A Constant Gain Switched Resistor CMOS Variable Gain Amplifier using Feedback Capacitor Array

S.-G. Park (Korea)


Variable Gain Amplifier (VGA), Programmable Gain Amplifier (PGA), Radio Frequency Integrated Circuit (RFIC), Wireless Local Area Network (WLAN), CMOS analog integrated circuits, and switched resistor


Digitally variable gain amplifier (VGA) was implemented by using switched feedback capacitor array to achieve constant gain throughout the wide bandwidth frequency response in a standard 0.13μm one-poly-eight-metal (1P8M) RF CMOS technology for 802.11a/b/g/n WLAN application. According to the measurement results, the voltage gain of the VGA varying from 5dB to 67dB with 2dB steps and has a cut off frequency of from 60MHz to 200MHz, while maintaining a constant gain of under 0.5dB error. The circuit dissipates 11mA from a 1.2-V supply, and the chip area occupies 1.2 × 0.2 mm2 .

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