Dual-mode diplexer with high isolation based on amplitude and phase cancellation technique

Wattikornsirikul, Natchayathorn; Kumngern, Montree

doi:10.2528/PIERM18102503

Dual-mode diplexer with high isolation based on amplitude and phase cancellation technique

Author(s)

Wattikornsirikul, Natchayathorn

Kumngern, Montree

Date Issued

January 1, 2018

Type

Article

DOI

10.2528/PIERM18102503

Abstract

This paper presents a dual-mode diplexer with easy fabrication and high signal isolation based on amplitude and phase cancellation technique. The dual-mode structure enables a compact and easy asymmetrical frequency response which also requires considerable attenuation between the proximity in frequency of the transmitter and that of the receiver. Two back-to back dual-mode three-port diplexers and a 180° phase shifter are easily employed to construct the proposed device, which are combined to form a four-port dual-mode diplexer. A 180° phase shift in one branch can be achieved by delayed transmission line. The simulated and measured four-port dual-mode diplexers are designed at the operational frequency of Tx/Rx at 1.95 GHz and 2.14 GHz, respectively. The measured results of Tx/Rx dual-mode diplexer devices are presented of 48.5 dB Tx/Rx isolation. This four-port dual-mode diplexer achieves the isolation (S32) more than 21.5 dB compared with a conventional three-port dual-mode diplexer.

Citation

Progress in Electromagnetics Research M, 76, 187-195, 2018