Ultra-wide range variable phase-shifter for phased array applications

In this work, an ultra-wide range variable phase-shifter based on an injection-locked third harmonic self-oscillating mixer has been designed for its use in an active microstrip phased antenna array. The novel circuit provides the double functionality of tuneable phase-shifter and down-converter. Maximum conversion gain is obtained, through the optimization of a novel multiharmonic load at the input of the circuit. The ranges of synchronized operation are analysed versus the circuit parameters and the corresponding phase-shifts are calculated. The stability of the synchronized solutions of the circuit is analyzed by means of the envelope transient simulation method. An 11.3¿1.55 GHz phase-shifter/down-converter with a 3.25 GHz free-running frequency has been designed, providing a stable phase-shift variation at intermediate frequency of 465°.