文摘
A new circuit architecture for broadband digitally controlled variable gain amplifier (VGA) is introduced in this paper. The gain of the VGA is controlled precisely by using a resistor ladder attenuator and a closed-loop fine gain control block together. The bandwidth of the VGA is extended by applying a compensation technique in the fine gain control block. Implemented in 0.13-μm CMOS technology, the proposed VGA demonstrates a decibel-linear gain range of 24?dB (0-4?dB) with a gain step of 0.1?dB, a gain error <0.08?dB, a maximum input-referred third-order intercept point (IIP3) of 22.8?dBm, and a 3-dB bandwidth of 600?MHz.