A novel wideband phase shifter on coupled microstrip line

• Published in: Microwave and optical technology letters Vol. 66; no. 8
• Main Authors: Feng, Linping, Mo, Datie, Yu, Xinhua, Zhu, Haoshen
• Format: Journal Article
• Language: English
• Published: New York Wiley Subscription Services, Inc 01.08.2024
• Subjects: Broadband; coupled microstrip line; Coupling; Dielectric strength; etched slots; Insertion loss; Microstrip transmission lines; phase shifter; Phase shifters; Substrates; Transmission lines
• ISSN: 0895-2477; 1098-2760
• DOI: 10.1002/mop.34265

In this paper, a new 180° broadband phase shifter with coupled microstrip line with enhanced coupling by etched slots is proposed, which uses the energy coupling between the parallel‐coupled microstrip lines on the upper layer of the dielectric substrate and the etched rectangular slots (RS) structure on the bottom floor to circumvent the problem for achieving wide operating broadband and low insertion loss with compact size and simple structure. First, the main line and the reference line of the proposed phase shifter are composed of two parallel coupled lines and a uniform transmission line, respectively. Then, its working mechanism is described. Afterward, the phase shifter introduced an RS structure to increase the coupling strength, achieving a broadband of 69.7% and very low insertion loss (0.09 dB) with a phase shift of 180 ± 5°. Finally, a prototype 180° phase shifter with a center frequency of 3.0 GHz was designed, fabricated, and measured, and the measured results are good in agreement with the simulated ones.