X/Ku-Band Four-Channel Transmit/Receive SiGe Phased-Array IC

This paper presents a phased-array core chip integrating four transmit/receive channels and supporting circuitry on a single chip working over 8-16 GHz, covering X and Ku frequency bands. Each RX and TX channel has a VGA and a phase shifter featuring precise amplitude and phase control for RF beamforming. The phase-compensated VGA provides 16 dB of gain control range in 0.5 dB steps while limiting the corresponding phase variation to 3°. The phase shifter, based on the principles of a vector modulator, provides 360° phase control range with resolution better than 2.8°, rms phase and gain error less than 2.8° and 0.3 dB respectively. Each RX channel has more than 10 dB of gain, and the noise figure for maximum gain condition is better than 10 dB. In receive mode, input P1dB is -16 dBm per channel and in transmit mode, output P1dB is greater than 9 dBm over 8-16 GHz. Each RX and TX channel draws 65 mA and 85 mA respectively from a 3.3 V supply. The chip, fabricated in a 0.18 μm SiGe BiCMOS technology, occupies 4mm × 4mm and was put in a 7mm × 7mm LGA package.

I. Introduction

Electronically steered antenna arrays have the ability to steer a directed beam much faster than the mechanical counterparts. They can also alleviate problems due to interference by controlling placement of nulls in the radiation pattern. Despite being very well-suited for a wide range of applications including different kinds of radars and communication systems [1], use of phased arrays beyond the defense sector is rather limited due to high cost, which is primarily driven by the use of discrete components in existing solutions.