A 26.5-35 GHz High Linearity VGA with an RMS Phase Error of 0.9o-2.8o Utilizing a Novel Hybrid Coupling Technique in 45RFSOI

This paper presents a high-linearity common-gate VGA with a new gain control technique that uses a hybrid coupling network. This new technique mitigates the drawbacks of the conventional VGAs that results in high phase distortion across gain states. This VGA is implemented in GlobalFoundries 45RFSOI and achieves an RMS phase error of 0.9o-2.8o. This low error is maintained across 8.5 GHz of bandwidth. The measured IP1dB and IIP3 at the maximum gain state is 3.5 dBm and 11.5 dBm, respectively. The NF achieved is also kept low at 4.4-5.2 dB. Application areas are in high linearity beamformers for 5G and mm-wave applications.