A quad band quadrature branch line coupler using coupled line sections

Abstract

A new quad band quadrature branch line coupler (BLC) has been presented in this paper. The proposed BLC has been designed with the help of the T shaped coupled line sections, quad band impedance inverter. The BLC has been designed using Advanced Design System (ADS) software for f1 = 0.66 GHz, f2 = 1.52 GHz, f3 = 2.57 GHz and f4 = 3.44 GHz operating frequencies. The Rogers 5870 substrate has been selected for the BLC design. The BLC's S-parameters characteristics including insertion loss, isolation loss, quadrature phase and equal power division have been achieved with 0.58 dB maximum amplitude imbalance and 4.33° maximum phase deviation while preserved the <-10dB return loss and isolation loss at four frequency bands. The simulated results of the BLC verified the theoretical results of the BLC at four frequency bands.