Analysis and design of an innovative 19.5 GHz active phase shifter architecture, implemented in a 0.13 μm BiCMOS SiGe:C process, for beamforming in 5G applications

Abstract

This paper presents the design and implementation of a 19.5 GHz active phase shifter for beamforming. The proposed circuit is based on an original architecture using an Injection-Locked Voltage-Controlled Oscillator (ILVCO) associated with a polyphase filter and followed by a phase selection circuit. This phase shifter is synthesized using the phase selection circuit (PS) for coarse adjustment in the steps of 90° and the injection-locked VCO for a fine-tuning adjustment between ± 45°. According to the post-layout simulation results, the frequency tuning range of the VCO varies from 17.89 to 20.16 GHz in free-running mode. This behaviour allows to obtain a phase shift range of 360° with an injected signal having a power of -8.5 dBm and a frequency of 19.5 GHz. In these conditions, from a 1.3 V supply voltage, the full circuit draws a current of 20.47 mA and the mean output power is equal to − 15.58 dBm on 50 Ω load. The proposed circuit is implemented in a BiCMOS SiGe:C 0.13 μm process and the whole layout has an area of 1.51 mm² including all the pads.