Agilent 5989-7575EN Radar Measurements - Application Note c20140916 [88] free download

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Keysight Radar Measurements Application Note Introduction Today, different types of radar systems are used in a variety of applications: avionic, military, automotive, law enforcement, astronomy, mapping, weather, and more. Within this broad range of uses, several radar technologies have emerged to meet specific needs in terms of performance, cost, size and capability. For example, many police radars use continuous-wave (CW) radar to simply assess Doppler shifts from moving cars; range information is not needed. As a result, low cost and small size are more important than advanced capabilities and features. At the other extreme, complex phased-array radars may have thousands of transmit/receive (T/R) modules operating in tandem. In addition, these may rely on a variety of sophisticated techniques to improve per- formance: sidelobe nulling, staggered pulse repetition interval (PRI), frequency agility, real-time waveform optimization, wideband chirps and target-recognition capability are a few examples. To provide a foundation the discussion presented here, this application note starts with a brief review of radar basics. After that, the remainder of the note focuses on the fundamentals of measuring basic pulsed radars, which is the basis of most radar systems. Where appropriate, this note will discuss adaptations of certain measurements for more complex or modulated pulsed-radar systems. This note will emphasize the mea- surement of radar signals for transmitter testing. A separate Keysight application note titled Radar, EW & ELINT Testing: Identifying Common Test Challenges (publication 5990-7036EN) discusses signal generation and the characterization of radar receivers and electronic countermeasure (ECM) systems. Table of contents 1.0 Current trends and technologies in radar... 4 Current trends and technologies in radar... 4 2.0 Radar basics and the radar range equation... 5 The fundamentals of radar operation... 5 Pulse characteristics... 5 Pulse compression... 6 Doppler frequency... 7 The radar range equation... 8 3.0 Radar block diagram and the radar range e