Title :
Study of feedback technology for gain flatness of UWB LNA
Author :
Xie, Hongyun ; Zhang, Wanrong ; Li, Jia ; Shen, Pei ; Huang, Yiwen ; Huang, Lu ; Hu, Ning
Author_Institution :
Coll. of Electron. Inf. & Control Eng., Beijing Univ. of Technol., Beijing, China
Abstract :
The S parameter expression of the HBT with multiple feedbacks, especial the transmission gain S21, is presented and analyzed. Pure resistive feedback makes better input and output matching. Reactive feedback promotes the amplitude of S21 as the frequency increases, which compensates the inherent decrease of HBT´s gain in high frequency. The gain decrease induced by the resistive feedback is also counteracted. So the gain flatness is realized in the frequency band from 3.1GHz to 10.6GHz.
Keywords :
S-parameters; heterojunction bipolar transistors; low noise amplifiers; ultra wideband technology; HBT; S parameter expression; UWB LNA; feedback technology; frequency 3.1 GHz to 10.6 GHz; low noise amplifiers; resistive feedback; Energy consumption; Equivalent circuits; Feedback circuits; HDTV; Heterojunction bipolar transistors; Negative feedback; Noise figure; Pulse amplifiers; Scattering parameters; Ultra wideband technology; Low noise amplifier; Negative feedback; Reactive feedback; Ultra-wideband;
Conference_Titel :
Microwave, Antenna, Propagation and EMC Technologies for Wireless Communications, 2009 3rd IEEE International Symposium on
Conference_Location :
Beijing
Print_ISBN :
978-1-4244-4076-4
DOI :
10.1109/MAPE.2009.5355634
