Third Order Intermodulations Phase Shifting in Power Amplifiers for Spatial filtering in Multi-beam 5G mmW Phased Array

Abstract

This paper proposes an innovative concept of spatial third-order intermodulation products (IMD3) filtering in millimeter-wave 5G phased arrays. This technique aims to relax the linearity constraints on the power amplifiers (PA) and thus power consumption. Implementation of independent control of the phase of IMD3 is proposed by using the nonlinear output capacitance of metal-oxide semi-conductors (MOS) amplifiers under phase-controlled second harmonic injection. The implemented control uses beamforming properties to perform spatial filtering of IMD3 product. A second harmonic injection on a power amplifier is proposed in STMicroelectronics CMOS065SOIMMW technology at 28 GHz. It shows phase control of IMD3 with a range of 35 degrees, allowing relaxation up to 17 dB on the linearity of large phased array power amplifiers.