Radar signal generation and processing techniques are growing ever more advanced. These advances are being driven by the need to improve resolution (the ability to detect targets that are very close together) and reduce radar spectrum occupancy. Reducing spectral occupancy can serve two goals: reduce interference and minimize the probability of intercept (POI). These advanced designs are being implemented as digital radar where the data converters are very close to the antenna and parameters such as demodulation, matched filtering, range gating, etc. are performed using digital signal processing (DSP). Field Programmable Gate Arrays (FPGAs) are emerging as a useful approach to digitally implemented radar systems due to flexibility and cost reduction. The use of FPGAs and DSP means that the effectiveness of the radar system is becoming increasingly dependent on the pre-distortion, filtering and detection algorithms.
This application note will provide a summarized review of radar essentials and some of the challenges in modern radar systems. This is followed by an explanation of how to take advantage of the increased sample rate, analog bandwidth, memory, and digital outputs found in the Arbitrary Waveform Generators (AWGs) in order to: increase resolution, decrease false target returns, and increase the probability of detecting actual targets. The last section will cover troubleshooting the radar transceiver chain and generation of a phase modulated (Frank Code) pulsed radar signal using Tektronix RFXpress software.