Coupled resonator based wideband millimeter-wave circuits

This paper discusses wideband millimeter-wave (mm-wave) circuits based on coupled resonator. Compared with conventional RLC resonator, the coupled resonator has more degrees of design freedom, with small chip area overhead. The coupled resonator also has the following useful properties: frequency boosting, “phase plateau” and wideband response, which are utilized to implement a wideband injection-locked frequency doubler, a phase shifter and a wideband amplifier in mm-wave frequency band.