A 12GHz 22dB-gain-control SiGe bipolar VGA with 2° phase shift variation

A 12GHz VGA is presented that shows a gain control from -9dB to 13dB in a linear-in-dB fashion. As the gain is changed, the phase shift over the entire 10 to 14.4 GHz bandwidth varies as little as ≤2° due to a compensation circuitry that reduces the input-output phase shift sensitivity to gain variations. The VGA prototypes, implemented in a SiGe bipolar technology, show a noise figure of 5.1 dB, an IIP3 of -3dBm, and a power consumption of 83mW.