White Papers

This White Paper provides a view on radar waveforms for Aerospace and Defence and commercial radar systems. Waveforms such as pulse and pulse-Doppler signal, continuous wave and frequency shift keying waveforms are described. It also shows continuous waveform trends designed for specific needs and application differences of continuous wave radar compared to pulse radar systems.

This application note introduces the practical aspects of cable and antenna testing. It covers interpreting measurement results and instrument operation including calibration options such as CalReady and QuickCal using FieldFox configured as a cable and antenna analyzer. Measurement examples are provided showing techniques for measuring insertion loss, return loss, and locating faults in a transmission system.

Accel-RF Instruments President, Roland Shaw, addresses the significant parameters that affect the reliability assessment of solid state power amplifiers utilizing GaN HEMT semiconductors. This tradeoff study contrasts three architectures of SSPA designs to demonstrate how a chosen topology may affect the mean time to failure of the resulting amplifier module. The example details the decision process for a multi-stage GaN HEMT Ka-band frequency SSPA utilizing the following topologies: Septum binary combiner, Waveguide radial combiner and Parallel-plate combiner. These architectures are viable candidates for Ka-band SSPA designs due to the low-loss combining techniques used in the implementation of the balanced output stage.

How Accurate Are Your High Power RF Measurements? Accurate power measurements of RF signals can be difficult to achieve without the proper calibration infrastructure. This paper describes a flow calorimeter that lowers the uncertainty of 100 W, 1 GHz measurements to 0.43% of full scale. Using this system, through-line wattmeters can be calibrated automatically with an uncertainty of 0.55%.

This Application Note describes testing S-parameters under pulsed conditions. A constant power level calibration is included. A LDMOS S-band radar power transistor is used as example DUT. The pulse profile mode of the R&S ZVA is used to analyze the time-dependent behavior of the DUT.

The Defense Industry is facing many challenges. From shrinking budgets to Better Buying Power 2.0 to increased competition for program wins. And, for applications that rely on RF and microwave technologies, the supply base is highly fragmented resulting in increased costs and risks for prime contractors. Mercury is pioneering open architectures for RF/Microwave solutions and has implemented a concept around Advanced Microelectronics Centers (AMC) to provide the design, manufacturing and testing capabilities needed to deliver on key program needs. This whitepaper discusses why open architectures will be a game changer in RF/Microwave and what makes the AMCs unique and relevant.

AR has just completed a brand new edition of our sought after full line product catalog. We have expanded our facility to provide unparalleled high power capabilities to test RF amplifiers in excess of 10,000 watts and added various new RF and microwave power amplifiers to our extensive product lines. The catalog continues to be easy to use, with "find-it-fast" charts and color coding to help get right to whatever you need for RF & EMC testing.

Next generation radar systems face multiple difficult demands. The pace and variety of new requirements need multi-use/function/mode adaptive radars, to be used for different applications. This whitepaper reviews existing pulse measurement test methods; discusses advantages/limitations; and introduces new test method that takes advantage of high-speed digitizing architecture, offering the industryâ??s highest resolution/timing accuracy level.

Many passive multiport devices - such as power dividers/combiners, baluns, hybrids, and impedance transformers - rely on electromagnetic (EM) coupling for their intended functions. In the microwave range this is typically achieved through a usage of capacitive (electrical) coupling between the closely spaced transmission lines. Adding the magnetic coupling by utilizing the ferrite-loaded transmission lines allows significantly expanding the operation band both up and down in frequencies. This paper provides the theoretical explanation for such a broad frequency effect of ferrite materials and illustrates the theory by presenting the 3-D simulation results for 2:1 impedance ratio ferrite transmission-line transformer.

To amplify weak signals received by the antenna in communication systems, low noise amplifiers (LNAs) are deployed. LNAs are used in various applications such as GPS receivers, wireless data systems, satellite communications, cellular handsets, radio systems, etc..