Analysis of Three-Conductor Coupled-Line 180 degrees Hybrid for Single-Balanced Subharmonic Mixer Design in 0.15-mu m pHEMT Technology

作者：Su Chun Chi^*; Lin Chih Ming; Hung Shih Han; Huang Chia Chen; Wang Yeong Her

来源：IEEE Transactions on Microwave Theory and Techniques, 2014, 62(10): 2405-2414.

DOI：10.1109/TMTT.2014.2338272

• Balun
• broadband
• down-converter
• hybrid
• subharmonic mixer (SHM)

A novel 180 degrees hybrid with two lambda/4 sections of three-conductor coupled-line structure inhered different operating frequencies with overlapped characteristic and perfect isolation between the Sigma-port and Delta-port is employed to implement a Ka- to M-band single-balanced subharmonic mixer (SHM) in a 0.15-mu m GaAs pHEMT process with a compact die size of less than 0.82 x 0.83 mm(2). The thorough analysis based on the scattering matrix of the 180 degrees hybrid is also presented. Incorporating the inherent features of the 180 degrees hybrid with an antiparallel diode pair configuration, the proposed SHM achieved a wide operating bandwidth from 37 to 85 GHz with low conversion loss from 9 to 14 dB, enhanced local oscillation (LO)-to-RF isolation and 2LO-to-RF isolation under 10-dBm LO power level. This proposed architecture is really attractive to SHM design in modern millimeter-wave territory.

• 出版日期2014-10