A Miniaturized Microstrip-Based Phase Inverter as a Phase Delay Component at 24 GHz

This paper presents a miniaturized microstrip-based phase inverter (PI) operating from 23.05 to 25 GHz. The proposed miniaturized PI integrates interdigital capacitors and meander slots on the ground plane while utilizing only two metallic vias to achieve a compact size. The circuit area of the layout is only 24.4% when compared to the original microstrip-based PI and 32.4% when compared to the ordinary 180°-delay meander line. Simulated and measured results demonstrate an 8.13% usable bandwidth, 0.53-dB average insertion loss, and phase deviation within ± 10° from 23.05 to 25 GHz. This design offers promising size reduction and competitive performance for microwave circuit integration.