Articles

Electronic Quadrature Hybrid Duplexer for Wireless Simultaneous Transmit Receive Operation

This article presents a new four-port electronic device – the directional quadrature hybrid isolator (DQHI). The topology of this duplexer is similar to the four-arm quadrature hybrid (QH) except for a 90° non-reciprocal phase shifter (NRPS) replacing one of the λ/4 Z 0 arms.