Integrated hybrid coupler for monopulse radar and biomedical sensors applications

Abstract

The 180-degree hybrid coupler was designed to miniaturize in the frequency range from 5 to 10 GHz with a 0-degree phase shift in the summation port and a 180-degree phase shift in the differential port. Miniaturization can minimize the power dissipation, and a passive component can solve the microstrip lines substrate materials’ complex accessibility problem! The metal layer of the inductor will be chosen and designed in Cadence with the corresponding permeability and permittivity of the metal. The design process started from rat-race hybrid coupler microstrip line in Advanced Design Systems (ADS) to lumped passive component and further active 65nm CMOS implementation in Cadence. Simulation result shown via material from center-tapped inductor has created a parasitic inductance which shifts the frequency of interest bandwidth 1GHz to the left after EMX simulation. The passive circuit has a forward gain of -10dB and a return loss of around -6dB. Literature studies have been carried out to miniaturize the hybrid coupler and its performance parameter analysis. The final result has shown that only four passive components were used, which covered the frequency band of interest, 5GHz.