A 23 G Hz RF - beamforming Transmitter with > 15.5 dBm $\mathrm{P}_{\text{sat}}$ and >21.7% Peak Efficiency for Inter-satellite Communications

This paper presents a 23GHz RF -beamforming transmitter (TX) for inter-satellite communications. By combining a variable gain amplifier (VGA), a phase shifter (PS), and a four-inductor-coupling differential quadrature-signal (IQ) generator, a power-efficient design with high compactness is demonstrated. The chip is fabricated in a 130nm SiGe BiCMOS technology. It achieves a measured saturated output power (Psat) of >15.5dBm and a peak TX efficiency of >21.7%, with 2.09° RMS phase error and >29.3dB maximum power gain. The realized mm-wave TX supports 64-QAM with a 900Mbps data rate, the Error Vector Magnitude (EVM) of 4.98% (-26.06dB), the Adjacent Channel Power Ratio (ACPR) of −30.1dBc, and TX efficiency of 8.52% are measured at 9.2dBm output power. The core area of this TX is 0.9mm x 0.23mm.