A Compact and Miniaturized Broadband Phase Shifter Using Coupled-lines.

In this paper, a compact and miniaturized broadband phase shifter using coupled-lines (CL) is proposed. This broadband phase shifter merely consists of two sections, one pair of CL as the reference and another two parallel CLs as the main body. An analysis of even-odd mode on the theoretical circuit is shown to explain the basic principle of the proposed phase shifter. For demonstration of this novel configuration, a broadband 90° phase shifter was designed and fabricated. The measured results present that the proposed phase shifter can provide a stable wide bandwidth (over 80%) of 90° phase difference with deviation less than 6.7°, good return losses more than 10 dB and low insertion losses less than 0.53 dB. [ABSTRACT FROM AUTHOR]