Substrate Integrated Components for Passive Millimeterwave-Frequency Beamforming Networks

Abstract

In this paper, we propose passive millimeterwave (mmWave) components for Butler matrix beamforming networks implemented in grounded-coplanar waveguide (GCPW) technology designed for integration and co-optimization with an antenna array operating in the 28 GHz 5G band. Within the frequency band of interest, covering the [26.5 GHz–29.5 GHz] spectrum, the insertion loss of the designed hybrid coupler and crossover stays well below 0.75 dB, while the amplitude imbalance remains below 0.5 dB and the phase imbalance does not exceed 5°.