Ultra-Wideband Quasi-Circulator Implemented by Cascading Distributed Balun With Phase Cancelation Technique

作者：Tang Si Da^*; Lin Chih Min; Hung Shih Han; Cheng Kai Wen; Wang Yeong Her

来源：IEEE Transactions on Microwave Theory and Techniques, 2016, 64(7): 2104-2112.

DOI：10.1109/TMTT.2016.2573279

• Broadband
• CMOS
• distributed amplifier
• phase cancelation
• quasi-circulator

This paper presents the implementation of a broadband quasi-circulator through a cascading distributed balun using a 90-nm CMOS process. The isolation, vertical bar S31 vertical bar, of the proposed three-port quasi-circulator can be acquired through the phase cancelation technique, by connecting an additional distributed amplifier in parallel between ports 1 and 3. The thorough analysis based on an eight-port chain matrix and scattering matrix is presented for refining the circuit parameters in the initial design. Measured results show that the proposed quasi-circulator attains a broad operation bandwidth ranging from 10 to 67 GHz. Moreover, the quasi-circulator also has good insertion gain of 0.5 to 4.8 dB, as well as isolation vertical bar S31 vertical bar, which is better than 23 dB. Consequently, the proposed quasi-circulator delivers wide bandwidth performance, good port-to-port isolations, good insertion gain, and high linearity based on the cascading distributed balun with phase cancelation technique.

• 出版日期2016-7