A new type of planar 180° hybrid using intentional impedance mismatch for improved bandwidth and arbitrary power division ratio

Abstract

A wideband planar 180 hybrid is proposed for arbitrary power division ratios and implementing cascaded planar structure. In addition, the proposed structure not only has the same function as the conventional ring hybrid, but also has a planar cascade connection when connecting other components because the output ports have same direction. The proposed planar 180 hybrid consists of two 3 dB couplers, and 4 transmission lines (TLs) with symmetrical TLs connected in series with different impedances of ZA and ZB. The design theory of the proposed structure is based on a cascaded multiport connection form, converged from transmission matrix to S‐parameter, and the ratio of ZA and ZB impedances is derived for wideband performance. The design equations are verified as the measurement results of the magnitude and phase characteristics. The proposed structure, regardless of whether 2 TLs are connected in cascaded form, has a 29% reduced area compared with the conventional ring hybrid.

Phase shift switching of a miniaturized ultra‐wideband hybrid coupler for 5G technology

“…The first one, is a hybrid coupler (branch line coupler) with a 90° phase shift difference, while the second (ring coupler) is a 180° phase shifter coupler. To understand the coupler's functioning, port 1 (∑‐port) and port 2 (Δ‐port) are considered as input ports, port 3 and port 4 are considered as output ports 13‐21 …”

“…To understand the coupler's functioning, port 1 (Σ-port) and port 2 (Δ-port) are considered as input ports, port 3 and port 4 are considered as output ports. [13][14][15][16][17][18][19][20][21] In general, we define each coupler with a scattering matrix of S-parameters, and through it, we can evaluate the performance of each coupler. 22,23 The proposed coupler can be designed and implemented through four major steps:…”