Linearization of a harmonic radar transmitter by feed-forward filter reflection

In order to generate a detectable harmonic-radar response from an electronic device, the required power-on-target is comparable to that observed directly below a cellular base station. Also, the signal emitted from the target is often very weak. This weak signal must not be masked by harmonics generated by the radar itself. Thus, high transmit power must be provided with high linearity for detection of a nonlinear-radar target. In this paper, a technique is presented which achieves better than 135 dBc harmonic distortion at 7 W output power, at transmit frequencies between 800 MHz and 1 GHz.