$L$- and $S$-Band Compact Octave Bandwidth 4-bit MMIC Phase Shifters

This paper presents the design approach and test results of
L
- and
S-
band compact monolithic microwave integrated circuit (MMIC) phase shifters (PSs) developed for octave band applications. The PS designs were based on an optimum topology selected for each bit for compact size and low insertion loss, and have on-chip integrated digital control. The MMIC PSs were fabricated employing GaAs-based high-performance 0.4-mum MSAG MESFET technology with multilevel-plating process. We achieved a chip size of 2.6 mm
²
, the smallest size reported to date.