Title :
A SiGe HBT low noise variable gain amplifier with controllable feedback of a p-i-n diode
Author :
Xie, H.Y. ; Lu, Z.Y. ; Gan, J.N. ; Jin, D.Y. ; Zhang, W.R. ; Ding, C.B. ; Liu, B.Y. ; Zhang, D.H.
Author_Institution :
Colledge of Electron. Inf. & Control Eng., Beijing Univ. of Technol., Beijing, China
Abstract :
A low noise amplifier with dB-linear variable gain has been designed and fabricated based on high performance SiGe HBT in this paper. Negative feedback technology has been adopted to change the transmission gain of HBT through variable resistance of a forward biased p-i-n diode in the feedback path. The simulation results and measurement results agree well in frequency of 1.8GHz for CDMA application. A dynamic gain control of 14 dB in a control voltage range of 0.6-3.0 V has been achieved through the controllable feedback of the p-i-n diode. The noise figure was always lower than 5.5dB when the controlled voltage changed and the minimum noise figure is about 2.6dB. Both input matching and output matching maintained constants under all controlled voltage points.
Keywords :
Ge-Si alloys; code division multiple access; feedback amplifiers; heterojunction bipolar transistors; low noise amplifiers; p-i-n diodes; CDMA application; SiGe; SiGe HBT; controllable feedback; dB-linear variable gain; dynamic gain control; forward biased p-i-n diode; frequency 1.8 GHz; low noise variable gain amplifier; negative feedback technology; voltage 0.6 V to 3.0 V; Gain; Heterojunction bipolar transistors; Impedance matching; Noise; Noise figure; P-i-n diodes; Voltage control;
Conference_Titel :
Microwave Conference Proceedings (CJMW), 2011 China-Japan Joint
Conference_Location :
Hangzhou
Print_ISBN :
978-1-4577-0625-7
Electronic_ISBN :
978-7-308-08555-7
