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Learn how to configure Rohde & Schwarz products to fit your application. Search our database by product, technology, or application to find relevant technical documents.
Search Application Notes & Cards
Learn how to configure Rohde & Schwarz products to fit your application. Search our database by product, technology, or application to find relevant technical documents.
34 Results
Test Solutions Based on R&S®CMX500 Platform
The evolution of mobile communication enters 5G New Radio (NR) era with pivotal features. Voice call service is however still considered as an indispensable element for mobile devices and worldwide network operators continue to maintain the voice service for their subscribers. In comparison to other Over-the-Top (OTT) voice services, such as WhatsApp©, Teams© etc., Voice over NR (VoNR) and Voice over LTE (VoLTE) maintain QoS, support well established handover mechanism and emergency call, and do not require to pre-install OTT app on the phone.In order to provide premium voice service and enhance the superb user experience, audio tests on mobile devices are essential before the product launch. Different audio test aspects among which acoustic, functional, performance and field tests need to be considered.This application note describes the performance test with focus on VoNR audio quality measurement via electrical interface of the mobile device. The test solution is based on R&S®CMX500 with its integrated POLQA algorithm.
26-Jul-2023 | AN-No. 1SL401
Comprehensive test solutions guide for production and R&D
Small cell is a compact base station with smaller form factor and lower transmission power in comparison to the conventional macro base station. It covers relatively small area and serves less users. Usually, small cell can be integrated into the existing mobile network. By the evolution of radio access technology, the role of small cell has been changing through the evolution path. In the 2G/3G time, its role was to provide coverage in corner cases. Later during LTE, networks are not just providing coverage but capacity too. Small cells were then used to provide the addition capacity where required without adding additional spectrum. Now in 5G era, network operators use densification as an important strategy to provide seamless 5G services which demand coverage, capacity and performance too. With use cases requiring the 5G millimeter wave (mmW) rollouts, it makes sense to use small cells for densification due to the propagation characteristics of mmW.In this application note, we will shed light on the testing aspects of a small cell throughout the product life cycle with particular focus on the production test solution for the small cell device under test (DUT) in FR2 (frequency range 2, mmW frequency band) in Over the Air (OTA) environment for option 6 split based on radio communication tester R&S®CMP200 and OTA chamber R&S®CMQ200. The document is complemented with more insights into test solutions used in typical R&D test applications towards the second half of the application note.
19-Jun-2023 | AN-No. 1SL395
Solutions and Tipps for NR FR1 in TDD Downlink Mode
5G New Radio (NR) is a radio technology specified by 3GPP and was first released in 3GPP release 15. It is designed to target three use cases, i.e. enhanced mobile broadband (eMBB), massive machine type communication (mMTC) and ultra-reliable low latency communication (URLLC). Among these three use cases, eMBB represents actually a further evolution of mobile broadband communication from LTE standard. According to the technical performance requirement defined by IMT-2020, by deploying 5G technology, peak data rates of eMBB application are expected to reach 20 Gbps in downlink (DL) and 10 Gbps in uplink (UL) direction, respectively. Typical use cases of eMBB are data hungry applications, such as high resolution 8K video streaming, virtual reality (VR), augmented reality (AR) etc.Verification of a 5G capable user equipment (UE) with respect to its achievable maximum data throughput under controllable and deterministic test conditions is an essential process during the design phase of the product. Performance centric verification through identification of the data throughput bottleneck, product benchmarking against a golden device enhances tremendously the user experience in the end.This document focuses on 5G NR frequency range 1 (FR1) with TDD duplex mode in E-UTRAN New-radio Dual Connectivity (ENDC) operating mode. As 5G NR physical layer offers a plethora of flexibility, the motivation here is to provide a kind of guideline of relevant parameter settings to stimulate device under test (DUT)'s max throughput capacity. The status quo of the R&S solutions at the time when the application note is created are described. Shown feature sets are constantly evolving, so the screenshots used and the parameters shown may change.
07-Jul-2022 | AN-No. 1SL379
Software tool for fast and repeatable optimization of signal analyzer RF front-end settings
The signal conditioning in the RF front-end of signal analyzers is crucial to achieve the best performance with respect to image-suppression, noise-floor, dynamic range and other RF-key parameters.Precise signal levelling is especially important for complex measurements like Error-Vector-Magnitude (EVM). To minimize the measurement uncertainty from test system contributions over a wide range of different levels, the RF front-end needs to be adapted continuously according to the signal characteristics, signal power and frequency - ideally using an automatic levelling algorithm.This document describes the approach of a waveform specific, on-site characterization of the signal analyzer: For each waveform and frequency of interest, the instrument is evaluated in a first step. With this additional data, a fast and repeatable auto-levelling can be performed during the actual measurement.
24-Jan-2022 | AN-No. 1EF111
Functional Testing
Although data services in the context of eMBB, URLLC and mMTC are the pivotal drivers behind the 5G evolution, legacy services like voice and video communications still represent important services that operators want to offer to their subscribers. As part of the technology evolution, we have seen a major change from circuit-switched 2G networks with an initial focus on telephony to fully packet-switched 4G networks focused on internet data communications.This application note focuses on different details of voice services in 5G networks. Besides some theoretical background this document describes the procedure to setup a 5G network with R&S®CMW500 and R&S®CMX500 radio communication testers and how to carry out different functional voice call tests for 5G networks.
06-Oct-2021 | AN-No. 1SL364
Automated Solution with High Efficiency
5G New Radio (NR) presents dramatic challenges to the testing of User Equipment (UE) Power Amplifier (PA). Multiple frequency bands, flexible 5G operation mode, multiple PA performance metrics and the MIPI control interface increases the potential PA testing workload significantly. Manually repeating these tests under so many different scenarios can be costly and time consuming. An automated testing solution can help the test engineer to highly improve the testing efficiency.In this application note, it introduces an example of automated testing of 5G UE PA with R&S signal generator, signal and spectrum analyzer, vector signal explorer software, power meter along with power supply.The entire application note is organized with following structure:Chapter 2 outlines the challenges to 5G UE PA testing.Chapter 3 introduces the setup for 5G signal generation and analysis. For 5G signal generation, a batch program of converting *.CSV files with IQ vectors to ARB waveform files is introduced. For 5G signal analysis, the R&S®VSE software is recommended, which enables the separation of RF signal collection and measurement to improve testing efficiency.Chapter 4 provides the informative content about the integration of MIPI control interface for the PA ON/OFF state switching and register configuration.Chapter 5 gives a guide on the implementation of a quick power servo, in which the techniques to speed up the PA power level adjustment are discussed.Chapter 6 summarizes the automated testing procedure.
09-Aug-2021 | AN-No. 1SL365
Connecting simulation and measurements on physical devices
This application note is based on collaborative work between MathWorks® and Rohde & Schwarz. The focus is on linearization of a non-linear device, in our case the RF power amplifier. It is shown how simulation and the integrated functions of the Rohde & Schwarz instruments R&S®SMW200A and R&S®FSW work hand-in-hand with the simulation capabilities from MathWorks in MATLAB / Simulink. The goal is to provide a toolset to enable proper modeling and linearization approaches to optimize and verify the behavior of the power amplifier when used with complex wideband signals as used in 5G NR or latest satellite links.The application note brings code examples and an exemplary block set for MATLAB / Simulink to provide an easy start to replicate and use the described procedure.
05-Aug-2021 | AN-No. 1SL371
A turnkey 5G Field-to-Lab solution based on R&S®CMX500
5G New Radio (NR) is the fifth-generation radio interface and radio access technology (RAT) which was officially published by 3GPP in release 15. With the 5G technology, it enters a new era to meet the ever-increasing demands of mobile communications not only in the conventional cellular communication world, but also in the vertical industries.Since the commercialization of 5G NR, worldwide 162 networks have been deployed as per the report of GSA. On the path to the 5G NR network commercialization and service launch, field test is one of the essential user centric processes that User Equipment (UE) vendors should go through. Sophisticated features and versatile deployment options have to be thoroughly checked to ensure the reaching of certain confidence level before the official launch.However, field test is often linked with some challenges, such as► High costs due to the extensive drive tests► Time tedious analysis of a drive test that lowers the efficiency► Lack of test repeatability that makes the regressing tests impossibleWhat if providing an alternative solution in a laboratory environment to cope with all above mentioned challenges during the field test? R&S® as a world-wide well established test measurement equipment manufacturer and solution provider developed a 5G field-to-lab (F2L) turn-key solution, R&S®CM360°. It features► the simulation of the network with the real network configurations to avoid the cost intensive drive test by utilizing mobile radio tester R&S®CMX500► intuitive tools to visualize, drill down the problems and therefore enhance the debugging efficiency based on R&S®SmartAnlytics► the specialized key performance indicator (KPI) tests configured through real network data offered on R&S®CMX500 that guarantee the test reliability and repeatabilityThis application note aims to demonstrate the status of quo R&S®CM360° F2L solution.
16-Jul-2021 | AN-No. 1SL369
EN-DC Mode According to 3GPP 38.521-3
5G New Radio (NR) is a radio access technology (RAT) specified by 3rd Generation Partnership Project (3GPP) in release 15 technical standard which was first published in 2018. It is designed to enhance the spectrum efficiency to meet the diverse needs of wireless communication applications, such as enhanced mobile broadband (eMBB), massive machine type communications (mMTC) and ultra-reliable and low latency communications (URLLC).Two deployment modes are defined for 5G NR technology► non-standalone (NSA) mode involving both E-UTRA (access technology used for LTE) and 5G NR RAT► standalone (SA) mode allows the user equipment (UE) to access 5G core network (5GC) over LTE or 5G NR RATAll 5G NR air interface related core specifications as well as associated test specifications are included in the 3GPP 38 series specifications. In an UE product lifecycle, UE vendor is obliged to go through the device certification process by passing all the required conformance tests which include RF, protocol, performance tests before official launch of the product. RF conformance testing is of course essential for the market access. The conformity of 3GPP specification has to be ensured even in the early product R&D phase.This application note aims to guide the R&D reader through the 5G NR Frequency Range 1 (FR1) NSA RF UE conformance test according to 3GPP38.521-3 based on mobile radio tester R&S®CMX and associated web user interface R&S®CMsquares in interactive operation mode, i.e. manual operation mode, through test configuration examples. After reading this application note, the reader should be able to conduct 3GPP RF conformance tests with proper settings manually and understand measurement results in R&S®CMsquares.
25-Jun-2021 | AN-No. 1SL368
5G is the fifth generation of wireless communication technology supporting cellular networks. From GSM (2G) through to LTE (4G), each generation addresses technical challenges not overcome by its predecessor. As with previous generations, 5G requires new mobile devices and new base stations (BTS).Unlike previous generations, the use of radio beams in 5G requires completely new approaches with regard to the compliance, coverage, and quality of service testing.The new air interface is called 5G NR ("new radio"). This application note describes the measurement challenges of 5G NR and makes clear the benefits of using a monitoring receiver for measuring 5G signals.Real-world examples explain how to perform various key 5G measurements. The final section covers further 5G measurement possibilities using R&S products. "Over-the-air" (OTA) measurements are essential in 5G. This means staff from regulators and operators must work in unknown radio environments that vary according to location (e.g. urban or suburban) and mission (e.g. 5G BTS compliance testing or interference hunting). Measurement equipment must operate in a wide range of scenarios (close to the mast and far from the mast) and offer user-friendly functionality that enables the required measurements.Considering current global deployment trends, this paper focuses on the FR1 frequency band (sub 6 GHz).
07-Jun-2021 | AN-No. 1SL366
conducted conformance testing according to TS 38.141-1, Rel. 16
3GPP defines the Radio Frequency (RF) conformance test methods and requirements for 5G NR Base Stations (BS) in the technical specifications TS 38.141. This application note describes how all mandatory RF transmitter tests (TS 38.141-1, chapter 6), according to Release 16, can be performed quickly and conveniently with signal or spectrum analyzers from Rohde & Schwarz by either choosing manual operation or a remote control approach. Moreover, some test cases require additional signal generation equipment from Rohde & Schwarz.In Addition, a new Python software library comes with this application note to enable the remote control approach of base station testing. This example requires the RsInstrument module which can be found on pypi.org or installed via 'pip' and is provided as is.
27-Jan-2021 | AN-No. GFM313
conducted conformance testing according to TS 38.141-1, Rel. 15
3GPP defines the Radio Frequency (RF) conformance test methods and requirements for 5G NR Base Stations (BS) in the technical specifications TS 38.141. This application note describes how all mandatory RF receiver tests (TS 38.141-1, chapter 7), according to Release 15, can be performed quickly and conveniently with signal generators from Rohde & Schwarz by either choosing manual operation or a remote control approach. Moreover, one test case requires a signal or spectrum analyzer from Rohde & Schwarz which is highlighted seperately in the corresponding chapter.In Addition, a new Python software library comes with this application note to enable the remote control approach of base station testing. This example requires the RsInstrument module which can be found on pypi.org or installed via 'pip' and is provided as is.
02-Dec-2020 | AN-No. GFM314
radiated conformance testing according to TS 38.141-2, Rel. 16
3GPP defines the Radio Frequency (RF) conformance test methods and requirements for 5G NR Base Stations (BS) in the technical specifications TS 38.141. This application note describes all mandatory RF receiver tests (TS 38.141-2, chapter 7), according to Release 16.Furthermore, this document provides a brief introduction about the different R&S OTA antenna test solutions and how they are applicable for base station conformance testing. Rohde & Schwarz offers suitable solutions for any test case that is mentioned in this application note.
30-Jun-2020 | AN-No. GFM325
5G New Radio (NR) FR1 MIMO or beamforming downlink signal analysis especially the phase measurement of each MIMO layer and the determination of the phase difference between the MIMO layers are essential for the 5G base station product design.In this application note, it describes two test solutions from R&S® to cope with the 5G FR1 downlink MIMO signal analysis challenges either using R&S®RTP/RTO oscilloscope or R&S®NRQ6 frequency selective power sensor as RF frontend to capture the signal and together with R&S®VSE as post-processing tool for the IQ analysis.The aim of this application note is to walk the user through the necessary steps on both test solutions to enable the 5G FR1 downlink MIMO signal analysis.It is assumed that the reader has certain pre-knowledge of 5G NR physical layer. In case a refreshment is needed, please refer to the for further reading.
26-Jun-2020 | AN-No. GFM343
Thanks to their multichannel capability, oscilloscopes are ideal for multichannel applications such as the analysis of MIMO signals (e.g. 5G NR, WLAN), multi-antenna radar signals and differential high-speed digital signals (e.g. USB 3.x). These applications require the oscilloscope channels to be tightly aligned. This means the channel-to-channel residual skew has to be measured accurately so that it can be compensated. The channel-to-channel phase mismatch is reduced to a minimum, which plays a crucial role in achieving reliable measurement results.
06-May-2020
Signal Generation and Analysis
This Application Note supplements the video series, describing signal generation and signal analysis for Dynamic Spectrum Sharing (DSS) for LTE and 5G NR. The video series is located below this paragraph.In this illustration, a four frame (40 subframes) long LTE sequence will be created, and exemplary MBSFN slots inserted, carrying 5G payloads. That signal sequence will be compiled and played by the SMW signal generator. The FSW signal analyzer LTE and 5G NR personalities are then used to analyze and verify the content of each subframe/slot.Three methods are presented, (1) Manual Entry using the GUI, (2) SCPI command sequence/remote control and (3) configuration file. The latter variants require the download of various files, available at the bottom.The configuration file approach offers the fastest time to initially setup. The SCPI command sequences provides some insight of the functionality and settings at each step, and the supplied MATLAB® script (only core license required) provides a prototype to illustrate the programming of successive slots or subframes. The Manual Entry approach, using the instrument's front panel GUI, provides a step-by-step set-up instruction, which can itself be augmented with SCPI recording, for easy modification and programming.MATLAB® is a registered trademark of The Mathworks, Inc.
30-Mar-2020 | AN-No. GFM337
radiated conformance testing according to TS 38.141-2, Rel. 16
3GPP defines the Radio Frequency (RF) conformance test methods and requirements for 5G NR Base Stations (BS) in the technical specifications TS 38.141. This application note describes all mandatory radiated RF transmitter tests (TS 38.141-2, chapter 6), according to Release 16.Furthermore, this document provides a brief introduction about the different R&S OTA antenna test solutions and how they are applicable for base station conformance testing. Rohde & Schwarz offers solutions for any test case that is mentioned in this application note.
20-Dec-2019 | AN-No. GFM324
This application note is step by step guide on 5G New Radio (5G NR) signal generation and analysis capabilities using the R&S®SMW200A Vector Signal Generator equipped with software option SMW-K144 (5G NR option), in combination with the R&S®FSW Signal and Spectrum Analyzer and the software options FSW-K144 & FSW-K145 (5G NR Downlink & Uplink Signal Analysis). The R&S®VSE Vector signal explorer has also been used for analysis purpose in parallel to the FSW-K144 & FSW-K145 software options.It is assumed that the reader already has a deep understanding of the 5G New Radio standard as well as the testing aspects. If not, then please refer to the 5G eBook more a detailed overview on the fundamentals, procedures, testing aspects of the 5G NR technology.
22-Nov-2019 | AN-No. GFM322
conducted conformance testing according to TS 38.141-1, Rel. 16
3GPP defines the Radio Frequency (RF) conformance test methods and requirements for 5G NR Base Stations (BS) in the technical specifications TS 38.141. This application note describes how all mandatory RF performance tests (TS 38.141-1, chapter 8), according to Release 16, can be performed quickly and conveniently with signal generators from Rohde & Schwarz by either choosing manual operation or a remote control approach.In Addition, a new Python software library comes with this application note to enable the remote control approach of base station testing. This example requires the RsInstrument module which can be found on pypi.org or installed via 'pip' and is provided as is.
24-Oct-2019 | AN-No. GFM315
The document gives an overview and user guide about a link budget calculator for the main components of a basic OTA system. The calculator shall guide the user to plan link budgets, especially with respect to SNR requirements for the receive components and the vector signal analyzer. An Excel sheet containing the Link Budget Calculator accompanies the application note.
19-Mar-2019 | AN-No. 1EF104
Verifying 5G transmitted signals in the field with the R&S®Spectrum Rider FPH handheld spectrum analyzer
18-Mar-2019
This application note describes how to measure the antenna pattern of a mm-Wave device in the R&S®ATS1000 shielded chamber. This includes the required calibration of the measurement setup and a possible near field to far field transformation when measuring larger devices.
28-May-2018 | AN-No. 1MA304
This application note shows how to use Rohde & Schwarz signal generators and analyzers for testing early 5G New Radio components, chipsets and devices. Methods for easy creation and analysis of custom OFDM are explained. The solution provides● a single user interface for signal generation and analysis configuration● Flexible OFDM configuration and signal generation incl. flexible pilot and data allocation● User defined modulation schemes including complex scenarios, e.g. 5G NR PSS
23-Oct-2017 | AN-No. 1MA308
RF interference is one of the largest contributors to poor network performance. It shows up in dropped calls and low data throughput rates. Traditionally, interference hunting means you get a list of sites with bad performance from an OSS. This defines the areas for interference hunting quite well.If, however, the problem remains after attempts at mitigation, it could be because other sources often mask symptoms of RF interference. Usually the strongest masking is due to the overlap between the interference signal and your network's signals. Analysis could involve complete cities or even countries, an error-prone task when using traditional spectrum analyzers and/or portable receivers and one that consumes a significant amount of time and budget.A more automated solution for larger areas can make the effort involved more manageable. The Rohde & Schwarz network scanner family (R&S®TSME, R&S®TSMA and R&S®TSMW) plus the network problem analyzer (NPA) feature of the R&S®ROMES4 measurement software is such a solution. It allows you to perform a fast drive test with a fleet of cars and collect spectrum data for your targeted or even complete network area in next to no time. Back at your office, the NPA tells you where to send dedicated interference hunting teams with an analyzer or receiver to track down the source of interference. This paper introduces the approach in detail.
02-Oct-2017 | AN-No. 1MA293
Radio frequencies in bands around 28 GHz are being discussed as candidates for mobile communications of the fifth generation (5G). Beam steering will be a key feature in the context of 5G. It will be a major challenge to test the beam steering capabilities of base stations and user equipment in every phase from research and development through production. Conducted measurements will be mainly replaced by over-the-air measurements of electromagnetic radiation. Rohde & Schwarz offers the R&S®NRPM Over-the-Air (OTA) Power Measurement Solution that perfectly fits such measurement needs.Part of this solution are the R&S®NRPM-A66 antenna modules. They have integrated diode detectors. Thus, there are no cables between the antenna and the detector as in traditional setups. This avoids high and potentially unknown RF losses. The R&S®NRPM-A66 antenna modules with their integrated diode detectors are factory calibrated, which means that the user does not have to calibrate them to achieve highly accurate measurement results.This application note contains theoretical background on OTA power and pattern measurements. It gives step-by-step instructions for the verification of the power level and the radiation pattern of a device under test (DUT) in comparison to a golden device, and it presents an approach for verifying the accuracy of beam steering.
29-Aug-2017 | AN-No. 1GP118
Energy efficiency of RF Frontends (RFFE), especially transmitters, continues to gain greater prominence.Meeting the efficiency challenge is increasingly difficult at higher operating frequencies and bandwidths, such as those proposed for 5G.There is a group of transmitter RFFE architectures whose signal output is constructed from two, or more, efficiently generated components. This signal construction in effect, means that such architectures use predictive, post-correction linearization. Their predictive nature enables distortion to be completely eliminated.The capabilities of multi-channel signal synthesis setups with R&S®SMW200A, in combination with the R&S®FSW analyzer enable measurement, hence development, of these types of transmitters.The document focusses on devices for the 3.5 GHz NR (5G New Radio) candidate band, but its findings are equally applicable to developments and measurements for, for example, K-band satellite applications or mmW NR candidate bands, where efficiency is an even more crucial design target.
01-Aug-2017 | AN-No. 1MA289
What used to be the car radio has evolved from adding a cassette player to state of the art entertainment on the move. All this while keeping driver & passengers connected. The design challenge is to bring all the communication and broadcast standards into a small form factor that fits in the dashboard of the car. The RF modules need to support multiple standards in a single assembly and multiple modules are placed next to each other. The frequencies defined by the RF standards are in very close proximity and hence need to co-exist with each other. Moreover, the antennas inside the car are subjected to cross-coupling effects with mobile devices of passengers. To ensure the RF performance of the infotainment system, all of these scenarios need to be thoroughly tested.This application note highlights some of the RF measurement challenges and introduces Rohde & Schwarz equipment required for relevant RF characterization of car infotainment devices.
08-May-2017 | AN-No. 1MA275
Rapid and accurate verification of beamforming weights is required for example, for codebook generation or beamforming algorithm development or verification. This document describes the unique application of Rohde & Schwarz VNA (Vector Network Analyzers) to fully characterize the passive part of multi-element antennas intended for beamforming.A range of R&S VNA models are optionally equipped with multiple independent sources, whose relative amplitude and phase may be arbitrarily controlled ("defined coherence mode"), in addition to frequency and true time delay. These sources may be connected to individual elements of a multi-element antenna to derive and verify transmit (Tx) mode beamsteering and beamforming operation.The R&S®ZVA in "Defined Coherence Mode" can electronically be switched to / from the conventional S-parameter mode. Therefore, Sparameter and beamforming measurements may be performed efficiently within a single connection cycle of the antenna.Multiple VNA may be daisy-chained, to extend the concept shown to support an arbitrary number of ports.The R&S®Quickstep sequencing software may be downloaded from:https://www.rohde-schwarz.com/software/quickstep/
20-Mar-2017 | AN-No. 1MA278
The Doherty Amplifier continues to be rolled out in an increasing number of TxFE (Transmit Frontend) applications, as the quasi-linear amplifier architecture of choice.The advent of 5G, with its inevitable microwave or millimeter wave air interface, increase the design challenges associated with its construction; not least of all because of the potential for increased dispersion in the constituent amplifiers and combiners.This application note describes a measurement-based development methodology by which the Doherty Amplifier may be enhanced, increasing performance and/or performance bandwidth. This methodology is supported with a working example.The methodology may also be extended to balanced, spatially combined and anti-phase (so called "pushpull" or "differential") amplifiers, the latter often itself nested in Doherty configurations.The R&S®Quickstep sequencing software may be downloaded from:
26-Sep-2016 | AN-No. 1MA279
Designing and implementing an active phased array antenna requires precise characterization of individual components and the integrated performance of the array. To ensure an accurate test of the intended adaptive nature of the active phased array antenna, the embedded algorithms need to be tested as well.This application note aims to explain test procedures and give recommendations towards characterization of the relevant parameters for active phased array antennas and their passive subsystem, as often used in applications for Mobile Communication and RADAR. This application note describes transmit signal quality testing, multi-element amplitude and phase measurement techniques both in receive and transmit cases and introduces a new automated test methodology antenna radiation pattern measurement over frequency. This paper also describes the test system used for transmit and receive module (TRM) characterization in active array antennas.
04-Jul-2016 | AN-No. 1MA248