A 1.5 to 37 GHz ultra-broadband MMIC Mouw's star mixer

Abstract

A MMIC ultra-broadband star mixer using Mouw's hybrid junction is presented in this paper. The MMIC chip uses 0.15 mu m HEMT process. The chip is measured in three mounting environments, namely, absorber backed, 15 mil Al(2)O(3) substrate plus absorber, and conductor backed and all of them show ultra-broadband performances. The measured results show that the bandwidth is from 1.5 to 37 GHz except a resonant dip near. 23 GHz occurs in conductor backed case.. The IF 3 dB bandwidth is from DC to 2.5 GHz. The chip can be used as either up- or down-converter. Because the spiral layout of the Mouw's hybrid junction shrinks the area significantly, no off chip baluns are required. The chip size is 2 mm by 2 mm.