A 16–24-GHz SiGe Decibel-Linear Low-Gain-Error Digitally Controlled High-Efficiency Variable Gain Amplifier

This letter presents a 16–24-GHz decibel-linear low-gain-error variable gain amplifier (VGA) in 130-nm SiGe technology. Negative feedback resistor is used in current source to expand the gain variation range and improve decibel-linearity. The nonproportion metal-oxide-semiconductor (MOS) array is introduced to reduce the gain variation error. This design achieves a 15–0 dB gain variation range at 1-dB gain step with root mean square (rms) gain-error less than 0.3 dB. The measured OP
_1dB
is greater than 9.5 dBm between the 1-dB bandwidth of 16–24 GHz and this VGA consumes 8.8 mA from a 1.6-V supply.