Low noise integrated active antenna as image reject mixer (IRM)

Abstract

A patch antenna integrated with two Low Noise Amplifiers (LNA) is implemented to act as an Image Reject Mixer (IRM). The low noise active antenna system transforms a received radio frequency signal into two signals, which are out-of phase to each other. The image signals can be cancelled by the IRM. The antenna, LNA's, mixers and local oscillator (LO) are integrated into a single Active Integrated Antenna (AIA) module. An external IF 90/spl deg/ hybrid coupler is required in the IRM. The advantages of the LNA active antenna mixer system are low noise, image signal rejection, low cost and simple circuitry of front-end, and improved receiver sensitivity.