Architecture and Design of a New Non-Quadrature Vector-Sum Microwave Phase Shifter at 10 GHz With Maximum Residual Phase Error of 1.80°

Abstract

This paper presents the architecture, design, and simulation of a new vector-sum phase shifter for prospected use in applications that require low amplitude loss. The architecture is based on non-quadrature phase generation and synthesis. The phase generation is done by splitting the input signal into two equal-phase output vectors and delaying one signal vector to the other; while the phase synthesis is implemented by subjecting the vectors through path selection and variable amplification & attenuation before subtracting the different paths. A two-bit phase path selection was employed for achieving 360° of coarse & fine tuning. EM simulations of the phase shifter architecture was carried out using RT-Duroid 5880 specifications <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\varepsilon_{r}=2.2,\boldsymbol{\tan\delta=0.004)}$</tex> at center frequency of 10 GHz. A maximum phase error of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{1.82^{\circ}}$</tex> was obtained for the entire interval of 360 degrees of phase shift. With less than <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2^{\mathrm{o}}$</tex> of phase error, the proposed phase shifter architecture is feasible for millimeter-wave phase array beamforming applications; as it offers the possibility of lower power consumption with the use of lesser compartmental blocks (i.e. compared to a T-bridge phase shifter which uses a chain of multiple blocks that can lead to excessive losses of more than 30 dB).