An S-band 34dBm Stacked-HBT Phase Driver in 0.25μm BiCMOS Technology for GaN-Based Phased-Array Radar Transmit Chain

This paper describes an integrated S-band phaseshifter driver-amplifier to drive Gallium-Nitride (GaN) based power amplifiers in a phased-array radar transmit chain. This phase driver is implemented in a 0.25μm SiGe BiCMOS process and packaged into a QFN5x5. By using device stacking, the phase driver achieves an output power of more than 32.5dBm (1.7W) across the band (2.6-3.4GHz), with a maximum of 34.2dBm (2.7W). The RMS phase error is less than 3.75° at a 6-bit phase resolution. This enables a low-cost highly-integrated transmitter front-end for phased-array radar applications.