Wideband/image-rejection distributed mixer integrated with a CRLH leaky wave antenna

In this paper, we propose a distributed mixer integrated with a CRLH leaky wave antenna. The down converting mixer uses GaAs MESFETs as the nonlinear mixing devices, consisting of a CRLH transmission line in the gate line and a microstrip line in the drain line. The RF signal is received from the free space through the CRLH leaky wave antenna, whereas the LO signal is injected from the port of the same CRLH transmission line operated in the guided wave region. To synchronize the phase and align the unit-cell between the gate and drain line, we periodically loaded capacitors on the microstrip line. Due to the cutoff frequency of the CRLH-TL dispersion relationship, the proposed distributed mixers can exhibit image frequency rejection.