A two-channel Ku-band BiCMOS digital beam-forming receiver for polarization-agile phased-array applications

A 15 GHz two-channel receiver is presented for digital beam-forming applications. The receiver is based on a dual-down-conversion architecture for interference mitigation and results in a channel gain (I and Q paths) of 47.1 dB centered at 15 GHz, with an instantaneous bandwidth of 170 MHz. A 2-bit gain control (0-16 dB) is also provided at the IF stage. The measured NF is 3.1 dB and is independent of the gain state. The measured OP1dB is -11 dBm and the input P1dB is -57 to -41 dBm depending on the gain, and is ideal for satellite applications. The channel-to-channel coupling is <-48 dB. The chip is built using a 0.18-mum SiGe BiCMOS process, has ESD protection diodes on the RF and DC pads, consumes 70 mA per channel from a 3.3 V power supply and is 2.6times2.2 mm², including all pads. To our knowledge, this is the first high-performance Ku-band beam-forming chip in SiGe BiCMOS technology.