TVTL Mixer-First Phased Array Receiver for Space Frequency Interference Rejection

This article proposes a modified architecture for a mixer-first phased array receiver, addressing the crucial need for high linearity and low noise in commercial wireless applications. Instead of using the conventional low-noise amplifier (LNA), a new time-variant transmission line (TVTL) mixer is implemented as the initial stage. The monolithic microwave integrated circuit (MMIC) TVTL chip's performance exhibits a broadband conversion gain of up to 4.2 dB. Furthermore, it shows an input-referred P1dB of 12 dBm along with a low noise figure (NF) of 3 dB. Furthermore, a low-cost and low-power liquid crystal phase shifter (LCPS) is integrated into the LO path to minimize the impact of lossy phase shifters on the receiver's NF. To validate the proposed architecture, a 1-D electronically steered phased array is designed, fabricated, and measured. The array utilizes a four-element patch antenna array, four TVTL chips as mixers, and four LCPSs. Measurement results show continuous beam scanning from 0(degrees) to 20(degrees) elevation angle, confirming the effectiveness of the proposed architecture in achieving enhanced linearity and tolerance to strong in-band and out-of-band interference/jamming.