X-band SiGe bi-complementary metal–oxide semiconductor transmit/receive module core chip for phased array RADAR applications

This study presents a transmit/receive (T/R) module core chip with 4-bit operation using 0.25 μm silicon-germanium (SiGe) bi-complementary metal-oxide semiconductor (BiCMOS) technology, for X-band phased array RADAR applications. The T/R module core chip consists of sub-blocks such as low noise amplifier, power amplifier, phase shifter, single-pole double-throw switch and variable gain amplifier. Switches incorporate n-type MOS devices while amplifiers are implemented with SiGe heterojunction bipolar transistors. Measurement results for the complete core chip and its individual sub-blocks are reported here. Between 9 and 10 GHz, the constructed T/R module achieves about 11 dB gain for both receiver (RX) and transmitter (TX) chains, while it has -10.5 dBm receiver chain third-order intermodulation intercept point (IIP₃), and 16 dBm OP_{1 dB} for transmitter chain. Root-mean-square phase error is measured as 5, whereas noise figure varies between 4 and 6 dB. The total power dissipation of core chip is about 285 mW, with a total area of 4.9 mm².