Receiving Polarization Agile Active Antenna Based on Injection Locked Harmonic Self Oscillating Mixers

A polarization agile active antenna with phase shifter elements based on injection locked third harmonic self oscillating mixers is presented. This phase shifting topology provides the double functionality of continuous range phase shifter and downconverter. The phase shift value introduced by each circuit can be easily tuned through a DC voltage within a theoretical continuous range of 450° . The behavior of the isolated phase shifter circuit is studied, both as a function of the control voltage and versus frequency, through harmonic balance and envelope transient simulations. The polarization tuning performance of the complete active antenna is simulated, analyzing the impact of the operating parameters of the phase shifter on the overall behavior. A receiving polarization agile antenna with an input frequency band centered at 11.25 GHz and an output frequency band centered at 1.5 GHz has been manufactured for the experimental validation of the simulated results. A continuous range of polarization tuning has been observed, including two orthogonal linear polarizations along with left hand and right hand circular polarization.