Active quarter-wavelength dielectric radiator with circularly polarised radiation pattern

Abstract

An active circularly-polarised dielectric radiator array (DRA), which is integrated with a transistor, is formed by a special arrangement of four slow wave λ/4 dielectric resonators (DRs) together with a 90° phase shifter. Small size, low phase noise and high frequency stability are the major characteristics of this DRA at 480 MHz. With proper circuit topology, the DRA can be used as a Doppler motion detector.