Quadrature differential output six‐port rat‐race coupler

Abstract

This letter describes a design method for a six-port rat race circuit to obtain quadrature differential waveforms from a single end. The proposed six-port rat-race coupler succeeded in low insertion loss and wide bandwidth by using a 1/2 wavelength transmission line and an open stub. Over the frequency range from 0.89 to 1.05 GHz, a prototype 0.96-GHz-band six-port rat-race coupler was confirmed to have a transmission loss of 7.03 ± 0.45 dB, a reflection loss and isolation of 15 dB or more, and a phase error of within ± 3.3 • .

A compact differential branch‐line coupler using folded substrate integrated suspended parallel strip line

“…The differential or balanced circuits [1] have become more and more important in the modern communication systems, because they have advantages of suppressing environmental noise as compared to the single-ended circuits. The branch-line type coupler is generally used coupler in the RF and microwave circuits and systems, and differential or balanced branch-line couplers [2][3][4][5][6] have been investigated in the literature.…”

A Miniaturized Wideband 3 dB Rat-Race Coupler Utilizing Meander Lines

“…Moreover, the rat-race coupler can add and/or subtract the signals. Hence, this property is exploited in applications such as direction of arrival estimation [2,3] and quadrature differential waveforms generation [4].…”