Title :
A 1GHz CMOS variable gain amplifier with 70dB linear-in-magnitude controlled gain range for UWB systems
Author :
Cheng, Jia ; Huang, Fengyi ; Gao, Yang ; Wu, Lianhong ; Tian, Yu
Author_Institution :
Dept. of Radio Eng., Southeast Univ., Nanjing, China
Abstract :
This paper describes a design of an inductor-less variable gain amplifier (VGA) for UWB systems in a standard digital 0.18 ¿m CMOS technology. The VGA is implemented using four-stage modified Cherry-Hopper amplifier, and by changing the value of the feedback resistors in the Cherry-Hopper amplifiers, a variable gain from -17.4 dB to 52.7 dB can be obtained. The DC offset is reduced effectively by the use of dual feedback DC-offset cancellation network. The proposed VGA achieves a 3-dB bandwidth of 1 GHz with 70.1 dB gain turning range. It consumes 9 mW through a 1.8 V voltage supply. By avoiding the use of broadbanding techniques, such as peaking inductors, the amplifier cell only occupy an area of 38 ¿m × 80 ¿m (excluding the bondpads).
Keywords :
CMOS digital integrated circuits; UHF amplifiers; UHF integrated circuits; circuit feedback; gain control; ultra wideband technology; UWB systems; broadbanding techniques; dual feedback DC-offset cancellation network; feedback resistors; four-stage modified Cherry-Hopper amplifier; frequency 1 GHz; gain 70.1 dB; inductor-less variable gain amplifier; linear-in-magnitude controlled gain range; power 9 mW; size 0.18 mum; standard digital CMOS technology; voltage 1.8 V; Bandwidth; Broadband amplifiers; CMOS technology; Control systems; Feedback; Gain; Inductors; Resistors; Turning; Voltage; CMOS analog integrated circuit; Cherry-Hooper amplifier; DC-offset cancellation; UWB; variable gain amplifier (VGA);
Conference_Titel :
Communications, 2009. APCC 2009. 15th Asia-Pacific Conference on
Conference_Location :
Shanghai
Print_ISBN :
978-1-4244-4784-8
Electronic_ISBN :
978-1-4244-4785-5
DOI :
10.1109/APCC.2009.5375656
