Channel emulator RF module test hardware development

Abstract. The constant evolution of wireless communication systems set more and more stringent demands for the equipment used to test these systems. The hardware and software solutions used in the measurement equipment are extremely complex. Because of this complexity, the production process of these equipment needs to include strict testing. In this thesis, a radio frequency (RF) tester module for production testing of channel emulator RF module is designed. The thesis begins with an introduction to the device that needs to be tested, the channel emulator RF module. This RF module is part of the Keysight Technologies’ latest channel emulator model, PROPSIM FS16. The design of this thesis needs to enable the testing of the RF performance of the RF module transceiver. Benefits of modular production principle are introduced on a general level, and the justification for the production testing is given. It is concluded that testing hardware in a modular testing system is necessary for ensuring the production flow and for ensuring that the final product fulfills the specifications promised to the customer. Principles of RF testing are considered on a general level and the requirements regarding the designed RF tester module are presented. It is concluded that the RF tester module needs to route instrumentation signalling to the RF module. In addition, RF tester module needs to provide local oscillator signalling as well as DC power to the RF module. In the design part, the hardware design of the RF tester module printed circuit assembly (PCA) is presented. General RF design principles are discussed and aspects regarding the RF tester module PCA are considered with details. These include isolation, crosstalk and noise. Chosen components and the designed switching networks are elaborated and justified against the given requirements. It is found out that the instrumentation can be routed via a passive network, but the local oscillator networks need amplification to ensure correct power level. Active network power levels are verified with simulations and found out to be adequate. PCA layout design principles are reviewed on the extent that they play a prominent role in the RF PCA schematic design with the emphasis on the signal grounding issues. Lastly, the verification and calibration of the designed PCA is described, and the validation of the RF tester module in the complete RF test system is presented. It was found out that some local oscillator signal levels are lower in the final design, than was expected based on the simulations. This caused some delay in the validation phase, by producing false negative test results. After test parameter adjustments, it was found out that the required tests can be executed successfully with the designed RF tester module.Radiokanavaemulaattorin RF-moduulin testauslaitteiston kehitys. Tiivistelmä. Langattomien tietoliikennejärjestelmien jatkuva kehitys asettaa aina vain tiukempia vaatimuksia niiden testaamiseen tarkoitetuille laitteille. Näissä mittalaitteissa käytetyt laitteisto- ja ohjelmistoratkaisut ovat äärimmäisen monimutkaisia. Tästä johtuen, nämä laitteet täytyy tuotantovaiheessa testata erittäin tarkasti. Tässä opinnäytetyössä suunnitellaan RF-testimoduuli kanavaemulaattorin RF-moduulin tuotantotestaukseen. Aluksi esitellään testattava laite, eli kanavaemulaattorin RF-moduuli. Esiteltävä RF-moduuli on Keysight Technologiesin viimeisimmän kanavaemulaattorin PROPSIM FS16 osa. Tässä työssä esiteltävän laitteen tarkoituksena on mahdollistaa RF-moduulin lähetin-vastaanottimen suorituskyvyn testaaminen. Modulaarisen tuotannon edut esitellään yleisellä tasolla, jonka jälkeen perustelut tuotantotestaukselle esitellään. Päädytään johtopäätökseen, että moduulien testaus tuotannossa on välttämätöntä, jotta tuotannon kulku ja asiakkaalle luvatut spesifikaatiot voidaan varmistaa. RF-testauksen periaatteet käsitellään yleisellä tasolla, minkä jälkeen esitellään tämän työn RF-testimoduulin vaatimukset. Testimoduulin tulee reitittää testauksessa tarvittava instrumentaatio RF-moduulille. Tämän lisäksi RF-moduuli tarvitsee paikallisoskillaattorisignaalit ja DC tehonsyötön toimiakseen. Suunnitteluosiossa käydään läpi RF-testimoduulin piirilevysuunnittelu. RF- suunnittelussa huomioon otettavat seikat käsitellään niiltä osin kuin ne ovat relevantteja tässä työssä. Näitä ovat isolaatio, ylikuuluminen ja kohina. Valitut komponentit ja suunnitellut kytkinverkot esitellään ja perustellaan aiemmin esiteltyihin vaatimuksiin pohjaten. Havaitaan että instrumentaatiolle riittää pasiivinen kykentäverkko, mutta paikallisoskillaattorien verkkoihin tarvitaan vahvistusta. Aktiivisten verkkojen tehotasot testataan simuloinneilla ja havaitaan riittäviksi. Suunnittelun lopuksi käsitellään piirilevyn layout-suunnittelun RF-teknisesti tärkeimmät seikat, merkittävimpänä maadoitus. Lopuksi työssä suunniteltu RF-testimoduuli verifioidaan ensin piirilevytasolla, kalibroidaan ja validoidaan lopullisessa testijärjestelmässä. Havaitaan että välitaajuusoskillaattoreiden signaali on alhaisempi kuin on arvioitu. Tämä aiheuttaa virheellisiä testituloksia ja viivettä testirajojen asettelussa. Testiparametrien säädön jälkeen voidaan todeta, että työssä suunniteltua RF-testimoduulia voidaan käyttää RF- moduulin testausjärjestelmässä

LTE Spectrum Sharing Research Testbed: Integrated Hardware, Software, Network and Data

This paper presents Virginia Tech's wireless testbed supporting research on long-term evolution (LTE) signaling and radio frequency (RF) spectrum coexistence. LTE is continuously refined and new features released. As the communications contexts for LTE expand, new research problems arise and include operation in harsh RF signaling environments and coexistence with other radios. Our testbed provides an integrated research tool for investigating these and other research problems; it allows analyzing the severity of the problem, designing and rapidly prototyping solutions, and assessing them with standard-compliant equipment and test procedures. The modular testbed integrates general-purpose software-defined radio hardware, LTE-specific test equipment, RF components, free open-source and commercial LTE software, a configurable RF network and recorded radar waveform samples. It supports RF channel emulated and over-the-air radiated modes. The testbed can be remotely accessed and configured. An RF switching network allows for designing many different experiments that can involve a variety of real and virtual radios with support for multiple-input multiple-output (MIMO) antenna operation. We present the testbed, the research it has enabled and some valuable lessons that we learned and that may help designing, developing, and operating future wireless testbeds.Comment: In Proceeding of the 10th ACM International Workshop on Wireless Network Testbeds, Experimental Evaluation & Characterization (WiNTECH), Snowbird, Utah, October 201

Optimisation of Bluetooth wireless personal area networks

In recent years there has been a marked growth in the use of wireless cellular telephones, PCs and the Internet. This proliferation of information technology has hastened the advent of wireless networks which aim to increase the accessibility and reach of communications devices. Ambient Intelligence (Ami) is a vision of the future of computing in which all kinds of everyday objects will contain intelligence. To be effective, Ami requires Ubiquitous Computing and Communication, the latter being enabled by wireless networking. The IEEE's 802.11 task group has developed a series of radio based replacements for the familiar wired ethernet LAN. At the same time another IEEE standards task group, 802.15, together with a number of industry consortia, has introduced a new level of wireless networking based upon short range, ad-hoc connections. Currently, the most significant of these new Wireless Personal Area Network (WPAN) standards is Bluetooth, one of the first of the enabling technologies of Ami to be commercially available. Bluetooth operates in the internationally unlicensed Industrial, Scientific and Medical (ISM) band at 2.4 GHz. unfortunately, this spectrum is particularly crowded. It is also used by: WiFi (IEEE 802.11); a new WPAN standard called Zig- Bee; many types of simple devices such as garage door openers; and is polluted by unintentional radiators. The success of a radio specification for ubiquitous wireless communications is, therefore, dependant upon a robust tolerance to high levels of electromagnetic noise. This thesis addresses the optimisation of low power WPANs in this context, with particular reference to the physical layer radio specification of the Bluetooth system

System-level design and RF front-end implementation for a 3-10ghz multiband-ofdm ultrawideband receiver and built-in testing techniques for analog and rf integrated circuits

This work consists of two main parts: a) Design of a 3-10GHz UltraWideBand (UWB) Receiver and b) Built-In Testing Techniques (BIT) for Analog and RF circuits. The MultiBand OFDM (MB-OFDM) proposal for UWB communications has received significant attention for the implementation of very high data rate (up to 480Mb/s) wireless devices. A wideband LNA with a tunable notch filter, a downconversion quadrature mixer, and the overall radio system-level design are proposed for an 11-band 3.4-10.3GHz direct conversion receiver for MB-OFDM UWB implemented in a 0.25mm BiCMOS process. The packaged IC includes an RF front-end with interference rejection at 5.25GHz, a frequency synthesizer generating 11 carrier tones in quadrature with fast hopping, and a linear phase baseband section with 42dB of gain programmability. The receiver IC mounted on a FR-4 substrate provides a maximum gain of 67-78dB and NF of 5-10dB across all bands while consuming 114mA from a 2.5V supply. Two BIT techniques for analog and RF circuits are developed. The goal is to reduce the test cost by reducing the use of analog instrumentation. An integrated frequency response characterization system with a digital interface is proposed to test the magnitude and phase responses at different nodes of an analog circuit. A complete prototype in CMOS 0.35mm technology employs only 0.3mm2 of area. Its operation is demonstrated by performing frequency response measurements in a range of 1 to 130MHz on 2 analog filters integrated on the same chip. A very compact CMOS RF RMS Detector and a methodology for its use in the built-in measurement of the gain and 1dB compression point of RF circuits are proposed to address the problem of on-chip testing at RF frequencies. The proposed device generates a DC voltage proportional to the RMS voltage amplitude of an RF signal. A design in CMOS 0.35mm technology presents and input capacitance <15fF and occupies and area of 0.03mm2. The application of these two techniques in combination with a loop-back test architecture significantly enhances the testability of a wireless transceiver system

High Speed Test Interface Module Using MEMS Technology

With the transient frequency of available CMOS technologies exceeding hundreds of gigahertz and the increasing complexity of Integrated Circuit (IC) designs, it is now apparent that the architecture of current testers needs to be greatly improved to keep up with the formidable challenges ahead. Test requirements for modern integrated circuits are becoming more stringent, complex and costly. These requirements include an increasing number of test channels, higher test-speeds and enhanced measurement accuracy and resolution. In a conventional test configuration, the signal path from Automatic Test Equipment (ATE) to the Device-Under-Test (DUT) includes long traces of wires. At frequencies above a few gigahertz, testing integrated circuits becomes a challenging task. The effects on transmission lines become critical requiring impedance matching to minimize signal reflection. AC resistance due to the skin effect and electromagnetic coupling caused by radiation can also become important factors affecting the test results. In the design of a Device Interface Board (DIB), the greater the physical separation of the DUT and the ATE pin electronics, the greater the distortion and signal degradation. In this work, a new Test Interface Module (TIM) based on MEMS technology is proposed to reduce the distance between the tester and device-under-test by orders of magnitude. The proposed solution increases the bandwidth of test channels and reduces the undesired effects of transmission lines on the test results. The MEMS test interface includes a fixed socket and a removable socket. The removable socket incorporates MEMS contact springs to provide temporary with the DUT pads and the fixed socket contains a bed of micro-pins to establish electrical connections with the ATE pin electronics. The MEMS based contact springs have been modified to implement a high-density wafer level test probes for Through Silicon Vias (TSVs) in three dimensional integrated circuits (3D-IC). Prototypes have been fabricated using Silicon On Insulator SOI wafer. Experimental results indicate that the proposed architectures can operate up to 50 GHz without much loss or distortion. The MEMS probes can also maintain a good elastic performance without any damage or deformation in the test phase

Shuttle orbiter Ku-band radar/communications system design evaluation

Tasks performed in an examination and critique of a Ku-band radar communications system for the shuttle orbiter are reported. Topics cover: (1) Ku-band high gain antenna/widebeam horn design evaluation; (2) evaluation of the Ku-band SPA and EA-1 LRU software; (3) system test evaluation; (4) critical design review and development test evaluation; (5) Ku-band bent pipe channel performance evaluation; (6) Ku-band LRU interchangeability analysis; and (7) deliverable test equipment evaluation. Where discrepancies were found, modifications and improvements to the Ku-band system and the associated test procedures are suggested