A new MMIC broadside coupler using an array of air-bridges for directivity enhancement

Author

Sheng-Fuh Chang ; Jia-Liang Chen ; Wen-Lin Chen ; Hann-Ping Hwang

Author_Institution

Dept. of Electr. Eng., Nat. Chung Cheng Univ., Chia-Yi, Taiwan

Volume

14

Issue

6

fYear

2004

fDate

6/1/2004 12:00:00 AM

Firstpage

304

Lastpage

306

Abstract

A new quadrature broadside coupler is proposed, which employs an array of air-bridges to enhance directivity via its phase-equalization effect on the c-mode and /spl pi/-modes. The realization of air-bridges follows a standard MMIC fabrication process. An experimental chip fabricated on the 75-μm GaAs substrate verifies the air-bridge effect and shows wideband characteristics of the coupling of 3.2/spl plusmn/0.4 dB, the insertion loss of 3.9/spl plusmn/0.4 dB, the output phase deviation from quadrature less than 6/spl deg/, and the isolation greater than 18 dB from 20 to 40 GHz.

Keywords

MMIC; microstrip directional couplers; 20 to 40 GHz; 39 dB; 75 microns; GaAs; MMIC fabrication; air-bridges array; directivity enhancement; phase-equalization effect; quadrature broadside coupler; wideband characteristics; Conductors; Coupling circuits; Dielectric substrates; Fabrication; Foundries; MMICs; Microstrip antenna arrays; Nonhomogeneous media; Phased arrays; Wideband;

fLanguage

English

Journal_Title

Microwave and Wireless Components Letters, IEEE

Publisher

ieee

ISSN

1531-1309

Type

jour

DOI

10.1109/LMWC.2004.824814

Filename

1303674