A New VGA Circuit Using a Feedback Structure in 0,35µm CMOS Technology

In this work, a new structure to design variable gain amplifier (VGA) circuit is presented. The VGA circuit has been designed in 0.35µm CMOS technology. The VGA circuit employs a pseudo-exponential function. The VGA circuit works in voltage mode. The VGA circuit has a negative feedback structure and it has no stability problem because the magnitude of the loop gain is less than 1 for low frequencies. With respect to simulations, the VGA circuit has a gain range of 27dB between -13dB and +14dB, bandwidth performance of 200MHz for the maximum gain, and power consumption of approximately 1.3mW.