A Fast Impedance Tuner Implementation in a Cognitive Radar for Synchronous Real-Time Optimization in a Congested Environment

As S-Band frequencies continue to be reallocated for sharing with wireless communications, radar systems are forced to operate in a spectrum that is becoming increasingly congested and contested. Based on other spectrum users, cognitive radar systems must quickly react, change operating frequency, and reconfigure for best performance to share successfully. A real-time impedance tuner is implemented within a software-defined radar (SDRadar) system demonstrated here for maximizing transmitter output power (and transmission range) in real time when changing frequencies to share spectrum. The SDRadar and reconfigurable impedance tuner are shown to achieve up to 46 percent improvement in range, with synchronous reconfiguration accomplished in less than 10 ms. Considering recent and parallel developments in high-power, quickly reconfigurable impedance tuners, it is becoming apparent that power handling, speed, and performance improvements are expected to revolutionize adaptive radar transmission.