Quadrature Phase Generation Using a Ring Resonator

This letter presents a novel microstrip-based design to generate quadrature phase signals from a single input. The operating concept relies on coupling to the electric field and the magnetic field at the fundamental mode of a ring resonator. Since the fundamental mode provides positive and negative fields, and since the electric field and the magnetic field have a 90° phase shift, a quadrature output is generated. The presented design of the quadrature phase generator is simulated, fabricated, and measured. The fabricated prototype operates at 3 GHz. The measured results show a good resemblance of a quadrature output.