Abstract

This paper describes a systematic method to design wideband 90° phase shifter circuits to be implemented using MMIC technology. The circuit structuresare based on the combination of two RC-all pass filters, and the proposed method allows the computation of circuit elements in a simple manner for minimum phase shift and amplitud errors over any frequency range. One of the RC-all pass filter structure is an active structure which has no losses. A 90" phase shifter circuit has been designed using this method, the phase shift errror and amplitud error are 2° and 1 dB over more than two octave bandwidth, ( 0.8 - 4.8 Ghz ).