Phase responses of harmonics reflected from radio-frequency electronics

Abstract

The phase responses of nonlinear-radar targets illuminated by stepped frequencies are studied. Data is presented for an experimental radar and two commercial electronic targets at short standoff ranges. The amplitudes and phases of harmonics generated by each target at each frequency are captured over a 100-MHz-wide transmit band. As in the authors' prior work, target detection is demonstrated by receiving at least one harmonic of at least one transmit frequency. In the present work, experiments confirm that the phase of a harmonic reflected from a radio-frequency electronic target at a standoff distance is linear versus frequency. Similar to traditional wideband radar, the change of the reflected phase with respect to frequency indicates the range to the nonlinear target.

First SIMO Harmonic Radar Based on the SFCW Concept and the HR Transfer Function

“…when the doubler is operated in its square-law region where the memory-less power series approximation is applicable [14,18,27].…”