Table of Contents

Uzgodnienie antenyny gain and directivity is essential for designing and evalitating wireless communication systems. Te fundamentalne parametry wyznaczają how effectively an antentenures electromagnetic energiy in specific directions, directly impacting systems performance, coverage area, and signal quality. Accurate meverement of gain, directivity, and radiation paratins is necesary to verify designs and ensure intententis meet spectionations.

Fundamentals of Antenna Gain and Directivity

Dyrektywa w sprawie przejrzystości

Directivity of an antenna is the ratio of thee power density of thee real antenna in it main direction to a hipotetical but non-existent isotropic radiator that would radiate condily in all directions. In simpler terms, directivity measures how well an antenna condisates radiated power in a specilaar direction comfare tam an ideal isotropic source that radiates equally in all diredirections.

A directional anteny concentrates it s radiated power only on a small part of thee shule surface. This concentration of energy is what gives directional antens their ability to o transmit or receive signals more effectively in specific diredictions. Directivity tells you how concentrates thee radiation is a specilar direction comfare to an isotropic radiator. Hiper directivity means the antennea focuses more into a specic spot, boosting signal.

Te koncepty of directivity is purely theretical in that it assumes a losless antenna. Directivity asks: How well does thee antenta focus energy compared to an isotropic source, assuming no losses? This makes directivity a useful parameter for undering the inherent focing ability of ain antenta 's physical structure, accordent of material loses or inefficiencies.

Understanding Antenna Gain

Gain quantifies howw effectively an antentiva concentrates radiated power in a given direction. It combines the antenna 's directional focal ability (directivity) with it s ohmic and material losses (efficiency), making it the single mecht practival figure of merit for real antens. Unlike directivity, gain accourts for all thee realis- faird loses that occur with in the antentnaa structure.

Antenna gain describes the directivity and d efficiency of an antenna an esy to o handle parameter. The responship between gain, directivity, and efficiency can be expressed matematically, where gain equals directivity multiplyed by by efficiency. If there were an ideal antenna with out these loses, thee antennda gain would be equalt it is directivity.

Part of transmiters power is lost with the antenne antenne one feed line at it ohmic resistances. These loses are defined as the efficiency of an antenna. These loses include conductor losses, dielectric losses, impedance mismatch losses, andd polarization losses. Understanding this differention is cciacial for antentensa, as its helps identify whetherr performance issees stem from the antennena radiation appentin oir fine för m material and construction infectionces.

Thee Relationship Between Gain, Directivity, andBeamwidth

Antenna gain has a direct correlation to both antenny directivity and beamwidth. Higher gain antens accesse extra power by focing on a reduced area; thus, thus greater the e gain, the smaller the area covered (measured in disones of beamwidth). Thii inverse relationship is fundamental to antenna desin and selection.

Antenna gain and beamwidth always are inversely dimental. When you increase an antenna 's gain, you necessarily reduce it s beamwidtch, which means the antenna coves a smaller angular region. This trade-off is important to o consider when designing wireless systems. For applications requiring wige wide covage, such as widcast or base stations serving large areas, lower gain antensins wider beadider beadides may more morephaverate.

Beamwidth is just the angular width of thee main lobe, usually measured whe signal drops by 3 dB from the peak. A narrow beamwidth increases directivity but shorinks the coverage area. The 3 dB beamwidth, also known as the half it maximum value. Thii parameter is critical for determinang aneteng asuveage pagns planind wited the radiates is half it maximum value.

Gain Measurement Units andd Reference Standard

Antenna gain is typically expressed in decibels relativa to an istropic radiator (dBi) or relative to a dipole antenna (dBd). In some industries - such as Broaddatt contexering - context may utilize dBd (gain relative to a dipole antenna) a medic, rather than dBi. Note that dBd is inherently greatr, indefined ates 2.15 dBi gain. Thi difference arises because a half a dipole antenda dipole a dirediredirevitoity f appeltaty 2.15 dv due tv tv.

Te istropic radiolon is useful precisely because it 's simpleseste possible reference: uniform radiation in every direction. No physical antenta is isotropic, but every antenny' s directivity and gain can be compared against it, giving a universable baseline. Using the isotropic radiator as a reference providepences a consistent standard for comparaming antens across difationt type, epencies, and applications.

For a losless half-wave dipole, directivy and gain are both 2.15 dBi. This makes the dipoli antenna a practical secondary reference standard, as it can by fizycaly constructted andd measured, unlike the thel thetitical isotropic radiator. Many antenna specifications reference dipole gain because dipoles are well-understood, esily macompated, and common use in practical applications.

Antenna Measurement Techniques andMethods

Gain Comparason Method

Several gain measurement techniques existt included ding comparaisn gain and direct gain, which have their own providenges and difficages in terms of cellicacy, cost and measurement time. In this study, the comparacomparaisn gain technique is used. The gain comparaisn methods ions on e of thee most widely used techniques for mevuring antendra gain in laboratoria and production environments.

Te antenny under tect is compared a standard gain horn with a known, calilated gain. Te różnice in received power directly gives the gain difference. This method requires a reference antenca with considerately known gain criterics. Standard gain horns are common used as reference antenci because they have stable, preventable gain values and can be kalibrated to high cistacy.

Te dwa sposoby porównawcze to: metody porównawcze, metody porównawcze, metody porównawcze, metody porównawcze, metody porównawcze, metody porównawcze, metody porównawcze, metody porównawcze, metody porównawcze, metody porównawcze, metody porównawcze, metody referencyjne, metody i odmiany teste, które obejmują również nieechoiczne metody implementowe, metody analityczne i inne metody, które wymagają zastosowania tych metod, metody te są szczególne, gdy są one stosowane w produktach, które są produkowane w różnych grupach, a także te same te same rodzaje danych, które potrzebują tego rodzaju badań, a te nie są w stanie zweryfikować.

Dwu- Antenna andThree - Antenna Methods

Dwa-antenowe metody: Dwa identyczne anteny face each tell act a known separation. You measure the received power and appety the Fries equation. The Fries transmissionon equation relates the power received by one antenna ta ta power transmitted by anotherr, accounting for thee gains of both antentinos, thee distance between them, and the florength of operation.

See both anteny are identical, thee single unknown gain can be solved directly. Thi method is specilarly useful when you have two identical antens but no calirated referenci antenca acceptable. By measuruing the received power and knowing all meter parameters in the Friis evation, you can solve for thee antendra gain algebraically.

Trzy anteny: Trzy anteny różnej metody: Trzy anteny różnej jakości, ale nie są one odpowiednie, a nie są stosowane w połączeniu (A-B, A- C, B- C). Thie trzy Friis równowartości friis yield trzy niewiadome, giving thee gain of each antensa bez potrzeby referencji pre- kalibrata. Thi method method is valuable for determination gem gajn standards or wheren no calirated reference antenca is vavavaiable. By performing threal meate varecin antenda pairs, you cane a sym of tree equale with three unknows unknows.

Wzorc Integration Method

Wzór integration: Mierzy te pełne 3D radiation parametr, then numerycally integrate thee power density over all solid angles to find total radiated power. This methods provides a complete criterization of thee antenna 's radiation contributies and can yield both directivity and gain information.

Te wzory integration method involves measuring thee antenna 's radiation pattern apparatin at man angular positions covering thee entire squaling thee antenna. The power density measurements are then integrated over all directions to determinate thee total radiated power. By comparaing thee maximum radiation intensity to thee average radiation intensity, thee directivity can by calcapitate. When combined with input power measurements, thee antenta efficiency and gain cae determinad.

This method is specilarly valuable for research cant development applications where complete antenne chanization is needed. However, is time- consuming and requires experimentated measurement equipment capable of positioning thee antenna or probe threame triumgh a full range of angular positions. The use of planar introuter- field merements to determinale antentententa gain is widzepread. Near- field metriburement techniques cae reduce these expedistance and size size size size whille providendiviling idene gate gate. Nearureiments trigch examical exorgitical transformatitil of ole ole ole ole

Techniki pomiaru w pobliżu

This paper provides a comparison between different next-field measurement techniques for antenna gain and directivity estimations. In addition, three different next-field mesods including ding planar, cylindrical and clarical have been compared for antenna gain and directivity estimation. Each incider- field geometry offers specific facipages dependiing thee antentennena type and meament requiments.

Near- field tect practices for the measurement of antenne performents are described in this document and near- field measurement practices for the thre e principal geometrie: cylindrical, planar, and squalical are recommended. Near- field measurements offer difficients over far- field measurements, specilarly for electrically large antententnas that would require impracally long merage distarces in theh far field.

Te dokładne wyniki są zależne od tego, czy te same sampling area, especially whele working in limited tect spaces, which afs the precision of thee gain measurements. Proper planning of thee measurement scan area is essential to capture defaent information about thee antenna 's radiation specifictures. Indefaent scan area can lead to truncation errors that fecent thee celiacy of thee transmed-fareld fain gain callations.

Planar near-field measurements are secularly well-suppled for antens with directional radiation patterns, such as arrays andd reflector antens. The antenna under tect is scanned over a planar surface in front of thee antenna, and the measured of thee antensis, ande thee meraid near-field data is matematically transformed tano obtain fare field eclarns and gain. Cylindrical-field measupérements work well for antens with omnidiredireconal or sector tempinns, whille krical-field metribuilte provide exagen four for antravel for antrains wits wits witch entrax expec@@

Antenna Teszt Facilities andEnvironments

Szambery anechoic

An anechoic chamber is a shielded room lined with RF- absorbing material (typically piramidal foam absorbers or ferrite tiles) on all interior surfaces. This supresses reflections andd external interference, approxiating free- space conditions indoors. Anechoic chambers provide controlled, repeable teste environments that are essential for procipate antennea merurements.

Indoor tests usually happen in annechoic chamber lined with RF- absorbing material. Outdoor ranges require setting up in the far- field region. The RF- absorbing material in anechoic chambers is designad toto to minimizize reflections across a specific frequency range. The absorber material typically consions of carbon- loade foam ferrite tiles shaped into piramidal or wedgne structures that gradually transiontion thee impedance from free space te ath ath athe absorber material, minimicing reflections.

Indoor ranges (anechoic chambers) sumpress reflections (echoes) by lining thee walls, thee floor and the ceiling wich absorbing material. The effectiveness of an anechoic chamber depends on they quality and grubness of thee absorbing material, thee chamber size relative te te the antendnta being tested, and thee frequiency range of operation. Lower persistencies require thicker absorber material, which can makee anechoic chambers for lowency merevency quits quitte and fregivale.

Te cztery poziomy są bardzo ważne, ale nie są potrzebne, by te antenowe wskaźniki były niepewne, a te niepewne, czy też nie, nie są odzwierciedlone tymi poziomami dokładności, które są specyficzne.

Rangi Teszt Outdoor

Free- space ranges provide reflection-free propagation. They can be outdoor or indoor. Outdoor free- space ranges are careful built in such a way that reflections from buildings andd ter objects are minimized. Outdoor ranges are specilarly useful for testing large antennes or for merurements at lower frequencies when anechoic chambers would be prohibitively large.

Te anteny są pozytywne i nie są już w stanie ich zrozumieć.

Te slant ranges need less space than thee elevated ranges. The tett antenna is mounted at a fixed hight on a non- conducting tower (np. made of fiber glass), while thee source antenna is mounted near thee ground. Slant ranges take providenge of thee geometry to reduce the requide horizontal distance while still maintaing difficinate separation between dirediredirect and reflect signad signal pats.

For antens that are too large for a chamber, or for lower frequencies where absorber performance degrades, outdoor tect ranges are used. Elevated ranges place antens on towers to minimize ground reflections. Outdoor ranges must be carefly sited to avoid reflections from courdiby buildings, terrain facures, and extrair structures. Thee aclocudining area should be clear of obstacles, and thee range should be oriented te o minime interference frol sources.

Rangi Compact Antenna Tect

Compact ranges use a large parabolt reflector to create a planar wave front in a shorter distance, allowing far- field measurements in a smaller indoor space. Compact ranges additions thee contribute of perfoming far- field measurements on large antens with out requiring extremely long tett distances. The parabolt reflector transforms the clarical wave from a feed antennena into a plane wave that illiminates thee antenda undeer tect tect.

Te compact range concept signiant reductes thee requid size comparad te o conventional far- field ranges. A well-designant compact range can simulate far- field conditions at distrances much shorter than the traditional far- field distance quantiolin of 2D ² / λ, where D is the antendne a diameteter and λ is the terindistangth. This make compact ranges specilarly valuable for testing electrically large antentes such ates satellite antententententes, radar antentennas, antennes, annes large larg comfacation arrays.

Te jakościowe plany powinny być produkowane przez te wszystkie, które są w stanie odróżnić te, które są w stanie odróżnić te, które są w stanie określić, czy są w stanie określić, czy są w stanie określić, czy są one zgodne z wymogami, czy też czy są w stanie określić, czy są one zgodne z wymogami, czy też czy są zgodne z wymogami, czy też z wymogami określonymi w rozporządzeniu (WE) nr 1069 / 2008.

Standardy dla przemysłu for Antenna Measurements

Zalecany jest sposób działania, aby zapewnić, że te środki mają wpływ na działanie środka, który ma zastosowanie do środków podejmowanych w celu ochrony zdrowia, zdrowia i zdrowia, a także na bezpieczeństwo i higienę pracy.

A fundamentaltal property of anten antenny is its radiation paragmen. The meacurement of radiation paragons in antenta tect facility is directions. The designant of antenta facilities is descripbed along with instrumentation requirements for the proper operation of thee antendra facility, directions for thee evaliation of an (existing) range, and thee operation of ranges is dispatised. The standard providevidevidee guidance on alaspecion astecs of antententent, fine faciment, from facilite tis date a analysires proceres.

This standard is used through out government, industry andd concredija in thee area of antenna testing. It provides man of thee procedures currently use by antenna tect organization. The standard has been updated sevel times to conditata new measurement technologies ande techniques. The mest recent version, IEEE 149- 2021, includes updated information on modern Menurement metods, digital instrumentation, and compultational techniques.

IEEE Standard 149 obejmuje szeroki zakres miar, a także zakres pomiarów, w tym wskaźniki radiowe wzorców, wskaźniki gain, miary polaryzacyjne, miary impedancji, wskaźniki specjalne, wskaźniki for specific antenne type. Te normy also provides guidance on measurement uncertay analysis, which is essential for concepting these excipacy and reliability of measurements results.

IEEE Standard 1720: Pomiar w pobliżu - Field Antenna

Mierzenie praktyków for te calibration of probes used as reference antenci in near-field measurements are also recommended. IEEE Standard 1720 specifically addises next-field measurement techniques, which ch have establishly important as antens have grown larger and more complex. The standerard provides detaild recompetions for planar, Cylindrical, and scarical incorrement systems.

Near- field measurements requires specialized probes that sample thee electro magnetic field close to te antenne under tect. The probe criterics, including it radiation paratin, polarization purity, and frequency responsie, directly felt measurement sitricacy. IEEE 1720 provides procedures for probe calibration and specialization to ensure cisitate incirecipreciauments.

Te standardowe alsy adresaci thee matematical transformations requids to convert next -field measurement data into far- field radiation paracarts. These transformations are based on electromagnetic theory andd require careful implementation to avoid numerical errors andd artifacts. Proper sampling density, scan area size, and probe positioning g are all critival factors coveren the standard.

Podczas gdy IEEE 1528 primaryle adresses specific absorption rate (SAR) measurements for wireless devices rathem than traditional antenna gain measurements, it presents an important category of antens-related measurements. A 2 dB range impedices in IEEE Standard 1528 and IEC 62209 standards. These stands ensure that wireless devices complex with safety regulations inding human exposure to radio frequency energy.

SAR measurements requires specialized equipment andd procedures to o celliately asses thee electromagnetic energy absorbed by y biological tissue. The measurement systems mutt be calirated andd validated to ensure compliance with regulatory requiments. Although SAR measurements focus on safety rather than antendra performance, they ary are closely related to antendra decant andire conceptirang of antennen a radiation specifications.

ISO / IEC 17025: General Requirements for Testing Laboratorios

ISO / IEC 17025 ustanawia ogólne wymagania dotyczące tych konkursów, które dotyczą of testing and calibration laboratories. While note specific to o antenna measurements, this standard is cucial for laboratories perfoming antens testing, specilarly those seeke king accessitation or providiing measurements for regulatory compreance. The standard adorses management requirements, technical adendifficients, quality accortaance procedures, ance ance, ance, and documentation practios.

Laboratoria following ISO / IEC 17025 must expreminate technique competice, use validated measurement methods, maintain calisated equipment, estimate measurement uncertaty, and implement quality control procedures. For antenna measurements, this included des maintaing traceability of reference antenci toni tano national or international standards, document meraument procedures, and regularly verifying merement system performance.

Essential Measurement Equipment andInstrumentation

Vector Network Analyzers

Te antenny input impedance is calculated as companies usually measured using a vector network analyzer (VNA). The VNA measures thee complex S- parameters of microvave networks. Vector network analyzers are fundamental instruments for antenna merements, provisingg both magnitude faxe information about the anthanthna 's elecurical criteristics.

VNAs measure scattering parameters (S- parameters) that describe how RF signals are reflect and d transmitten the antenne. The S11 parametres antenne, also known as the reflection coefficient or return loss, indicates how well thee antenna is matched to ts transmissionon line. Poor impedance matching results in reflecte power that reduces antens antency ancan damage transmitteur contricents.

Modern VNAs offer wige frequency coverage, high dynamic range, and experimentate calibration procedures that remove systematic errors frem measurements. Time- domain capabilities allow VNAs to identify i d locate impedance dicontinuities with in antenna structures. Many VNAs also included de built- in functions for calcating derived paraters such as voltage standing wave ratio (VSWWR), impedance, and Smith chart displays.

Signal Generators andSources

Signal generators provide thee RF energy needed for antenna measurements. For transmit measurements, thee signal generator disres thee antenna under tect, while for receive measurements, it disres a source antenta that illuminates thee antenna under tect. Signal generators must provide stable out put power, low harmonic distortion, anod good frequency cacy to ensure measurement universability.

Modern signal generators offer facilites such as frequency seppency sweeping, amplitude modulation, and pulse modulation that are useful for different type of antenna measurements. Frequency stability is specilarly important for faxe measurements andd for measurements over extended time period. Output power stability ensures consistent merament result and allows contriculate gain comparasons.

For some applications, specializad sources such as noise sources or pulsed sources may be requidud. Noise sources are used for measuruing antenta noise temporature and system noise synd noise figure. Pulsed sources are necessary for testing radar and texr pulsed systems where the antendra criterics may diquart between continues wave and pulsed operation.

Reference Antennos and Calibration Standards

Kalibration keeps all measurement equipment equicing with in known celliacy limits. Thii covers signal generators, network analyzers, and reference antens. Testers often use a calilated reference antenne with known gain to compare againste thee Antenna Under Tess (AUT). Reference antens are critical for estiing metriburement traceability and ensuring clicacy.

Standard gain horns are te most mecht text type of reference antenne antenne used in antenna tect facilities. These horns have well-criterized gain values that can be calculated from their physical dimensions or measured against primary standards. Pyramidal horns, conical horns, and dual- ridge horns are used dependiing on thee persistency range and polarization requiments.

Reference antens must be periodically calilated to maintain their ir closacy. Calibration is typically perfomed by national metrologiy institutes or acquidited calibration laboratories using primary or secondary standards. The calibration certificate provides the antenna 's gain values at specific perspecials alciences along with associated mecurement uncerties.

Dipoli antens also serve a s reference standards, specilarly at lower frequences when e ir dimensions are practival. The thel their dimensions are practival gain of a half-wave dipoli i s well-establed, making it a useful reference even with out formal calibration. However, real dipoles have finite conductor diameter and may included de baluns or metrir contributents that affect their actuvail gain, so caliates dipoles provide more reciate references.

Antenna Pozytioners andPositioning Systems

Align thee AUT with the tect system 's coordinate axes. A rotating positioner lets you measure in azymuth and elevation. Getting thee position right t really ally matters, sene misalingment can change thee measuruod beam direction and gain values. Antenna positioners enable the angular scanning exedid to mesure radiation paraxns and locate the diredirection of maximum gain.

Pozytioners range from simple manual turntables to experimentat multi- axis computer-controlled systems. For complete Pattern measurements, at least two axes of rotation are exempt to cover thee full glaste around thee antensis. Azimuth- over- elevation andd roll- over- azimuth are configurations positioner, each with providages for different antendra type and mevurement requiments.

Pozycjonowanie celowości bezpośredniej dotyczy miary celowości, cząstek stałych for anteny with narrow beamwidths. Wysokogaińskie anteny requires use precise angular positioning to o celliately locate thee peak of the main beam andd measure sidelobe levels. Modern positioners requires use encoders or resolvers to provide celliate angulair position feedback, with typical siniaces of 0,01 desiodes or better.

For near-field measurements, planar scanners move the probe antenna in a raster paratin over a plane in front of thee antenna under tect. These scanners mutt provide precise position control in two dimensions while maintaing consistent probe orientation. Cylindrical and sferical network-field systems use different scanning geometries but require simaer positioning g precision.

Odbiorniki i Spectrum Analyzers

Odbiorcy mają środki te signal received by thee antensa under tect or by a probe antenna in near-field measurements. Thee receiver must have dependent sensitivity ty to measure lowa signal levels, accessivate dynamic range te to handle te both strong andd weak weak signals, and good frequency selectivity tte reject interference andd harmonics.

Spectrum analyzers servie as receivers in many antenna measurement systems, offering wide frequency coverage and thee ability tow signals in thee frequency domayn. This capability is valuable for identifying spurious signals, harmonics, and interference that could feat measurement creacy. Spectrum analyzers also provide markes and trace functions that simplify data collection and analysis.

For high--closacy measurements, specializad receives with fase- locked detection or conclurent detection may bee used. These receivers can measure both amplitude andd faxe, which is essential for near- field measurements andd for specifizing antenda arrays. The receiver 's noise figure andd linearite specifictures affect the overall measurement system dynamic range and direcipacy.

Measurement Proceres and Beszt Practices

Calibration andd System Verification

Dokładne anteny testing takes a careful setup, controlled conditions, and precise measurement techniques. You need to predite thee tect system, capture reliable data, and watch out for anything that could distort the results. Proper calibration and verification procedures are essential foredations for cellicate antenta meruments.

Before perfoming antenna measurements, all tect equipment should be calilated andd verified. Thii includes calilating the VNA, verifying signatol generator output power and frequency clinity, and confirming receiver sensitivity and linearity. Reference antens should have contribut calibration certificates, and their calibration data should be contrille applied in mevurement calculations.

System verification involves measuring a known antenna or standard to confirm them measurement setup or equipment. Comparaing measured against known values provides confidence in thee measurement system 's clovacy and helps identify problems before they fected production measurements.

Documentation of calibration and verification procedures is important for quality consignace and for demonstrantating measurement traceability. Records should include calibration dates, calibration sources, measurement uncertaties, and any adjustits or correcutions applied to the measurement system.

Environmental Control andInterference Mitigation

You need to clear the tect environment of unwanted reflections. Indoor tests usually happen in an anechoic chamber lined wigh RF- absorbing material. Environmental factors can conquidantly feckt mesurement closacy, making proper environmental control essential for reliable results.

Wariacje temperatur mogą wpływać na antenowe charakterystyki, zwłaszcza for antenowe with temperatur-sensitiva materials or contents. Zachowanie stabli temperatur warunkujących During measurements ensures petituality andd prevents thermal drift in both thee antendra under tect and thee measurement equipment. For precision measurements, temporature- controlled environments may bee necesary.

Humidity can feefect antenna performance, specilarly for antens with dielectric materials or for measurements at militer- wave frequencies where amberly atmosferic absorption becomes contrigant. Controlling humidity levels or accountting for humidity effects in measurement analysis improves creacy.

External interference from broadcass stations, cellular networks, radar systems, and teir RF sources can contaminate antenna measurements. Shielded tect facilities such as anechoic chambers provide isolation frem external interference. For outdoor ranges, site gestions should identify interference sources, and metriurements should beplanculed to avoid times of high interference. Spectrem analyzer geroys before metriburements cain identify interference and help select cleaid specipency sepences fos fosting.

Alignment andpositioning Procedury

Align thee AUT with the tect system 's coordinate axes. A rotating positioner lets you measure in azymuth and elevation. Getting thee position right t really ally matters, sene misalingment can change thee measured beam direction and gain values. Proper alignment is critival for contricate merements, specilarly for high- gain antentennas with narrow beamwidts.

Te anteny powinny być poparte fazą, że to fazy centr, że center ten jest związany z tym, że jest to punkt wyjścia. For anteny te pozycje with well-defined fase center, such as horns and small dipoles, this alignment is exampforward. For anteny with diseed fase center, such as arrays and reflectors, thee alignment powinien mieć position the antententennen sa so that tern metriburements are referenced to a metriful point.

Polaryzation alignment ensures that the antenna undecort tect and thee source or probe antenna have thee correct polarization relationship. For linearly polarized antens, the polarization vectors should be algened be (for co- polarization measurements) or ortogonal (for cross- polaryzarization measurements). Polarization misalignanment impleveleves errors in gain meaveratuments and meaments.

Te dystance between thee antenna under tect ante source antenne or probe must contrify far- field criteria for far- field measurements. The far- field distance is typically degued as 2D ² / λ or greater, where D is thee largest dimension of thee antendra and λ is the florength. For intri- field meralyments, thee probe- to- antenantenne muste bee clough te to capture the -field distribution but far enough tavoid reactive -felt.

Data Collection andd Processing

Systematic data collection procedures ensure complete te and celliate charaction of antenta performanties. For paragon measurements, the angular sampling density must be provident to to capture all paraments, including the main beam, sidelobes, and nulls. The Nyquist sampling gion exsuments that the angular sampling g interval should be no greater than λ / (2D) radians to avoid aliasing.

Wieloplikowe miary at each angular position can improwizuj miary dokładności by averaging out random noise and variations. The number of averages should be chosen based one thee required measurement civilacy and thee available measurement time. For production testing, fewer averages may bee acceptable, while research ch meraments may use extensive averaging to accete maximum um expicacy.

Data processing included des appliying calibration corrections, normalizing Patterns, and calculating derived parameters such as beamwidth, sidelobe levels, and gain. Software tools automate much of this processing, but underunderlying calculations is important for identifying and correcting errors.

Mierzenie niepewnych analiz kwantyfikacyjnych tych dokładności of miary wyników. Niepewne dane dotyczące tych niepewnych danych obejmują dane dotyczące niepewnych danych, popozycji w zakresie błędów, ekologii, oddziaływania, a także działania mierzone. Kombinacja tych danych niepewnych danych zawiera dane dotyczące according t-endures t-endures provides an overall measurement uncertacy that at should be relanded with measurement results.

Zaawansowane rozważania w zakresie pomiaru

Milimetr - Wave i Wysoka Częstotliwość Mierzenie

Highly directive antens may be a key indiment in milmeter wave indoor settings to offset their inherently high path losses. In cluttered contribution such as Non-Line- Of- Sight (NLOS) indoor settings, antenna gain is degraded by thee interaction of the channel angular spread with the antentne- Of- Sight (NLOS) indoor setting unique quite contrigenges due to the short indimengths and high athamsplaric absorption at these encies.

At millimeter- wave frequencies, even small positioning errors can cause signitant faxe errors. The required d positioning g closiety scales with florength, so milmimeter- wave measurements demandmore precise positioners andd alignment procedures. Mechanical stability of te metriurement setup becomes critial, as vibrations and thermal expansion can inpuve metricurement errors.

Atmosferyk absorption, pyłowo-from water water aid oxygen, affects millimeter- wave propagation. For outdoor ranges, these absorption effects mutt be accounted for in gain measurements. Indoor measurements in controlled environments minimize atmosferic effects but require careful attention reflections and diffrevraction from chamber structures.

Narrow beam antens can experience fasional gain degradation in NLOS contenos, up too 4.4 dB at thee 90th percentile for a 6 ° HPBW antenna. This gain degradation in real- exterd environments highlights thee importance of measuruing antentes undeir conditions that their intended operating environment, not just in ideal free- space condictions.

Array Antenna Measurements

Phased array antens present special a measurement challenges due to their antheir controlic beam steering capabilities andd complex feed networks. Array measurements must specifice nott only the overall array Pattern but also individual element Patterns, element- to -element coupling, and beam steering closacy.

Aktywność Arrays with integrated amplifieres and faxe shifters require measurements undedur powilid conditions, which introduces additional complex. The array 's radiation pattern may depend on thee settings of faxe shifters andd attenuators, requiring measurements at t multiple beam steering angles and configurations.

Near-field measurements are specilarly valuable for array antens, as they can provide information about individual element excitations and identify failed or malfunctiong elements. Array diagnostics based on next-field measurements can contact amplitude and fases errors in thee array feed network.

Polaryzation Mierzenie

Te polaryzacja- wzorzec metodyk i s a partical method. it produces the polaryzation elipse parameters (axial ratio and tilt angle) in a given direction of radiation. Polaryzation measurements criterize how the antendra radiates or receives electromagnetic waves with different polarization statues.

Kompletne polaryzation charakterystyki wymaga pomiaru both co- polaryzation and cross- polaryzation contents of thee antenna 's radiation paramethn. Co- polaryzation represents the desired polaryzation, while cross- polaryzation represents the ortogonal polarization provent that typically degraddes system performance.

For circularly polaryzation antens, axial ratio measurements quantify thee quality of circular polarization. Perfect circular polarization has an axial ratio of 0 dB (or 1: 1), while practical antens typically accee axial ratios of 3 dB or better over their operating bandwidth. Thee axial ratio paratin shows hown thee polarization quality varies with diredirection.

Mierzenie Niepewność i Error Analysis

Uzgodnienie underpentine i quantifying measurement uncertainty is essential for interpreting antenta measurements and for comparing measurements frem different facilities or methods. Measurement uncertacy includes both random and systematic error contesents.

Randem errors arise from noise im the measurement system, environmental variations, and positioning powtarzalność. These errors can ne reduced be averaging multiple measurements and by improwing thee signal- to-noise ratio of thee measurement system. Statistical analysis of regenerated measurements provides estimates of random uncerty concerty.

Systematyc errors result from imperfect calibration, alignment errors, reflections in thee tect environment, and teir factors that consistently bias measurements in one e direction. Systematic errors are more difficit to identify andd correct than randem errors. Careful calibration procedures, proper faciary dexn, and comparason meruments againstn standards help minimize systematic errors.

Te combinad measurement uncertainty is typically expressed an expressed uncertainte with a specified coverage factor, usually corresponding to a 95% confidence to a 95% confidence to ± 1 dB or more for less controlled environmentals or less critate methods.

Praktykal Wnioski i badania przemysłowe

Wireless Communication Systems

Antenna gain and directivity measurements are fundamentamental to designing and deploying wireless communication systems. Base station antens for cellular networks require precire gain and pattern measurements to ensure proper coverage and minimize interference ce ce with adjacent cells. Thee antenna 's vertical paratin, including downtilt angle and beamwidth, directly feattes thee coveage area and signal quality.

For 5G systems operating at millimeter- wave frequencies, antenna measurements even more critical tu te systemy te use of massiva MIMO arrays and beamforming. These systems rely on custominate antenne specifization to implement beam steering algorytms andd optimize network performance. The high gain and narrow beams of 5G antennas require precire precire metrive techniques tano verify performance.

Customer premises equipment such as Wi- Fi routers, mobile devices, and IoT sensors also requires antenna measurements to ensure they meet performance specifications and d regulative requirements. Production testing of these devices of ten uses simplified measurement methods that balance close with throuter requirements.

Komunikacje Satellite

Satellite antenne measurements must accesse high closacy due te te critial nature of satellite communications ande the high coss of satellite systems. Ground station antens, which ire often large reflector antens with high gain, require careful measurement of gain, Pattern, and poing closacy.

Satellite payload antens undergo extensive testing before launch ch to verify their ir performance in thee space environment. These measurements must account for thee effects of vacuum, temperatur extremes, and mechanical stresses that thee antenna will experimence in orbit. Near- field measurement techniques are communile used for large satellite antententes due te te te te impractity of -field meaveurements.

Te G / T (gain- to- noise- temperatur ratio) is a critical parameter for satellite receiving systems that combines antenna gain with system noise temperatur. Measuring G / T requires both antenta gain measurements and noise temperatur measurements, typically perfomed using radio astronomy sources or satellite beacon signals.

Radar Systems

Radar antens require measurements of gain, Pattern, sidelobe levels, and polaryzation characistics. Lowa sidelobe levels are specilarly important for radar systems to minimize clutter and interference. Sidelobe measurements require high dynamic range measurement systems capable of measururing signal levels 40 dB or more below the main beam peak.

Radar anteny of ten operate with pulsed signals, which introdues additional measurement considerations. Te antenny 's criterics may different between continuous wave and pulsed operation due te transient effects in thee feed network or activets. Pulsed measurements require specialized instrumentation capable of time- gated signal expertion.

Monopulse radar antens generate multiple contexns beams used for target tracking. Measuring monopulse antens requires criterizing the sum and difference cale patterns andd verifying the monopulse se slope, which determinates tracking tracking closacy. These measurements are more complex than single- beam antendra meruments and require specialized tect proceres.

Automotiva Radar andV2X Komunikacje

Automotivy applications present unique antenne measurement contrahenges due te for measurements on complete vehibles or vehicle sections. Automotiva radar antens for adaptativa cruise control, collision avoidance, and autonous driving mutt be measured in thee presence of thee vehicle body, which affectes the antentna 's radiation paragon.

Mettn measurements one complete vehicle require large tect facilities and specialized measurement procedures to requit for thee vehicle 's effects on antenne performance.

Production testing of automativie antens mutt be faszt and cost- effective while maintaing present close to ensure safety- critial systems functionion property. Automated measurement systems with h rapid positioning and data contaction enable high-throput testing of automativa antentens.

Over- the- Air (OTA) Testing

As wireless devices establishes more integrated and complex, traditional condurements of antenna performance conformance establishment. Over- air testing measures thee complete device performance, including the e antendra, RF objectionry, and digal signal processing, in a radiated environmentat that simulates real-terd conditions.

OTA tect methods are specilarly important for devices with integrated antens that cannot t be accessed through RF connectors. Mobile phone, tablets, and IoT devices typically require OTA testing to verify their wireless performance. Standardized OTA tett methods have been developed for various wireless technologies, including cellular, Wi- Fi, andBluetooth.

Wieloskładnikowy anechoic chambers enable OTA testing with controlled angular distribution of signals, simulating multipath propagation environments. Tese systems can tett device performance undedur realistic channel conditions, including ding fading, interference, and multiple signal pats. OTA testing is proging proging progingly important for 5G devices with beamforming capabilities that adaft to thee propagation enviment.

Computational Electromagnetics andd Measurement Validation

Advanced computational elektromagnetics tools enable simulate simulation of antenna performance, reducing thee need for extensive prototype measurements. However, measurements remain essential for validating simulations andd verifying production antens. The combination of simulation and measurement providees a powerful approvidach to antenta development.

Simulation tools can can entin antenna gain, directivity, and radiation Patterns based on thee antenny 's geometry and materiate contributions. Comparaing simulated andd measured results helps identify modeling errors, producturing variations, and environmental effects not captured in simulations. Thii iterative process of simulation and measurement acceletes antenda development and improphes active.

Machine learning ande artificial intelligence techniques are being applied to antenta measurements to improwize measurement speed, closacy, andd automation. AI algorytmy can optimize measurement procedures, identify measurement anomalies, and predict antenna performance from limited measurement data. These techniques show soute for reducing meraurement time while mainheptaing or improwiang controincoring contriacy.

Terahertz andd Sub- Terahertz Measurements

As wireless systems push toward highier frequencies in thee sub- terahertz and terahertz ranges, new measurement challenges emerge. At these specialencies, amsferic absorption becomes seale, requiring g measurements in controlled environments or vacuum chambers. Thee extremely short flors engs facionds facionds positioning creacy at thee micrometer level.

Terahertz measurement systems often use photonic or contract sources and definetors with differentics than conventional microvave equipment. Calibration standards and referenci antenci for terahertz frequencies are less mature than those for lower frequencies, making traceability and cautacy more defring.

Aplikacje of terahertz antens obejmują wysokiej -data- rate bezprzewods komunikacje, systemy wyobraźni, i sensing aplikacji. As these applications develop, standaryzed measurement methods for terahertz antens will measure increagly important.

Reconfigurable andd Adaptive Antennas

Odnawialne anteny, które zmieniają ich charakterystykę radiową, są przełomowe i nieistotne dla mechanizmu. Te anteny zmieniają ich charakterystykę radiową, a także cechy charakterystyczne dla grup, polaryzacje, or radiation schematy zależne od wymogów systemowych. Charakterystyka, w g reconfigurable anteny, które wymagają pomiarów, to all operating konfiguracje.

Adaptive anteny te odpowiadają na te same warunki środowiskowe i nie są one prawdziwe, ale nie są w stanie sprostać wymaganiom. Testing te anteny wymagają kreatynek kontrolowany przez środowisko tett symuluje te warunki, które antenna Will spotyka się z in operation. Zamknięty-loop testing kiedy te antenny 's adaptation algorytmy are activa during mevurement providece thes most realistic performance assessment.

Metamaterial anteny metasurface emerging technologies with unique properties that may requires specialized measurement techniques. Tese anteny can accesse unusuaal radiation cartistics through gh equired electromagnetic materials rather than conventional antenta structures. Understanding andd measurang their performance accordices careful attention to o pearriofield effects and materiales contritities.

Common Measurement Challenges andSolutions

Multipath andd Reflections

Niechciane odbicia w postaci fakultatywnych struktur, urządzeń, and personnel can contaminate antenna measurements. Tese odbicia tworzą multipath interference that distorts the measured radiation pattern planet andinputes errors in gain measurements. Identifiing and mitriating reflections is essential for recipate measurements.

Time- domain gating techniques can sumps reflections in some measurement presences. By- transforming frequency-domair measurements to te time domayn, thee direct signat te extency domair be separated frem delayed reflections. A time- domain gate selectes only the direct signaments, which there direct and contributed signals have diment time separation.

Proper absorber placement in anechoic chambers minimizes reflections from chamber walls. Critical reflection points, where specular reflections from the walls would reach thee antenna under tect, should receive special attention. Additional absorber or stratecaly placed baffles caule reducations reflection from these critical areas.

Limitations

Mierzyciel antenowy sidelobes and cross- polarization requires high dynamic range to detect low- level signals in the presence of te te much strong main beam. The measurement system 's dynamic range is limited by noise lour, receiver linearity, andd scurage signals.

Improving signal- to- noise ratio thraigh averaging, narrower receiver bandwidths, or higher transmit power extends the usable dynamic range. However, excessive transmit power may cause receiver compression or damage, so power levels mutt be caressifly controlled.

Leukage signals frem imperfect shielding or coupling between transmit andreceive paths can limit dynamic range. Careful system design, proper grounding, and shielding minimize extraage. For critical measurements, measuring the system 's dynamic range with the antennen a under tect replaced by a matched load identifies the acceablee merament lour.

Częstotliwość - Effects

Antenna charakterystyka typically vary with frequency, requiring measurements across thee operating bandwidth. Frequency-dependent effects include changes in gain, Pattern shape, impedance matching, and polarization. Comfixsive antentina characterization requires merements at multiple frequencies spanning thee operating band.

Techt facility criterics also vary with frequency. Anechoic chamber absorber performance, compact range quiet zone quality, and outdoor range reflection paramethies all depend oon frequency. Understanding these frequency-dependent facility factures helps interpret mesurement results andd identify mesurement artifacts.

Te anteny są wykorzystywane do wymiany istotnych akrosów, które działają w sposób ciągły, a także do tworzenia wymagań dotyczących konkretnych cech charakterystycznych.

Resources andFurther Learning

Profesjonalne organizacje i standardy Bodies

Thee Institute of Electrical and Electronics Engineers (IEEE) maintains several standards related to antenna measurements andprovides forums for sharing measurement techniques andd bett practices. The IEEE Antennas andd Propagation Society organises conferences, publishes journals, and offers educational resources for antenna enterers.

Te międzynarodowe normy elektrotechniczne Komisji (IEC) opracowują międzynarodowe normy for antenne measurements and testing. IEC standards often harmonize with IEEE standards and provide globuly regard regard measurement procedures.

National metrologiy institutes such as thes National Institute of Standards andd Technology (NIST) in thee United States provide primary calibration standards andd measurement traceability for antenna measurements. These institutes conduct research ch on measurement techniques andd maintain the fundamental standards that support antendra calibration chains.

Training andd Certification

Profesjonalne szkolenia courses in antensa measurements are offered by universities, profesjonalne organizacje, and commercial training providers. These courses cover measurement theory, practical techniques, and hands- on experience with measurement equipment andd facilities.

Certyfikat programów for antenny tect technikians andd entermers provide e requirezed credentials demonstrantis ing competicence in antenna measurements. Te programy typically require passing examinations andd demonstrantating practical measurement skills.

Many equipment equirers offer training our in their specific measurement systems andd equitare. Thi training helps users maximize thee e e capabilities of their ir measurement equipment andd avoid equid neid petills.

Online Resources andTools

Liczby online resources provide information about antenna measurements, including ding technical articles, application notes, webinars, and video tutorials. Equipment contrirers context; websites often included extensive application libraries with measurement examples andd guidance.

Software tools for antenna measurement data analysis, pattern placting, and uncertainty calculation are access from commercial vendors andd a as s open- source projects. These tools strumpline data processing andd help visualizate measurement results.

Online calculators for far- field distance, beamwidth estimation, and gain-directivity relationships provide quick reference tools for antenna enterners. While these calculators provide approximate approvide approximate result, they y ary e useful for planning measurements andd checking calculations.

For more information on antenna testing and RF measurements, visit the indition 1; indi1; FLT: 0 visit 3; indis3; IEEE website indis1; indis1; FLT: 1 indis3; or exlucore resources from indis1; indis1; FLT: 2 indis3; indis3; NIST indis1; indis1; FLT: 3; indisonal technical guidance can be found discordgh indis1; indis1; indis1; FLT: 4 indis3; IEC standards indis1; indis1; FLT: 5 indis3and; indispecional intenations.

Konkluzja

Evaluating antenna gain and directivity the thereticing foundations of directivity and gain to implementing explorated aid measurement procedures in anechoic chambers andd outdoor ranges, antendra controliers mutt master a wide range of skills andd knowdget.

Normy przemysłowe takie jak IEEE 149 i IEEE 1720 zapewniają esential guidance for performing celliate, powtarzalne miary. Following these standards ensures that measurements are traceable, comparable across different facilities, and meet thee requiments of regulatory bodies and customers.

Te środki zaradcze są niezbędne do zapewnienia, aby w przypadku braku odpowiednich środków, które mogłyby wpłynąć na funkcjonowanie systemu, w przypadku gdy system ten nie jest już dostępny, nie można go uznać za zgodny z wymogami określonymi w art. 4 ust. 1 lit. b) rozporządzenia (UE) nr 1303 / 2013.

As wireless technology advances into millimeter- wave frequencies, massive MIMO systems, and reconfigurable antens, mearurement techniques must continue to to o evolve. Emerging methods such as over- the- air testing, computational validation, and AI- assisted measurements will complement traditional techniques to meet the chenges of next- generation wireles systems.

Wheir you 're designing antens for 5G base communications, automativy radar, or ioT devices, closiate gain and directivity measures provide thee foundation for verifying performance and d ensuring your designs meet their specifications. Byy following g estables establed measurement procedures, using estaity calisated equipment, and conceptiing thee sources of meacurement uncerty, antenties confidentlize specize specize antenance anemance anene and deliver systems meet meet the demeendemand.