무선 통신 시스템 응용을 위한 초소형화된 능동형 90° 위상차 전력 분배기와 결합기에 관한 연구

Abstract

This paper propose highly miniaturized active 90° phase difference power divider and combiner for application to wireless communication system. The conventional passive 90° power divider and combiner cannot be integrated on MMIC because of their very large circuit size. Therefore, the highly miniaturized active 90° phase difference power divider and combiner are required for a development of highly integrated MMIC. In this paper, the highly miniaturized active 90° phase difference power divider and combiner employing InGaAs/GaAs HBT were designed, fabricated on GaAs substrate. According to the results, the circuit size of fabricated active 90° phase difference power divider and combiner were 1.67 × 0.87 mm and 2.42 × 1.05 mm, respectively, which were 31.6% and 2.2% of the size of conventional passive branch-line coupler. The output gain division characteristic of proposed divider circuit showed 8.4 dB and 7.9 dB respectively, and output phase difference characteristic showed -89.3°. The output gain coupling characteristic of proposed combiner circuit showed 9.4 dB and 10.5 dB respectively, and output phase difference characteristic showed -92.6°. The highly miniaturized active 90° phase difference power divider and combiner exhibited good RF performances compared with the conventional passive branch-line coupler.