Analysis of Different Topology of Transformer Feedback LNA

Speaker:  Sadia Afroz

Host: MICS

Date: September 12 (Friday), 2014
Time: 3:00 PM - 4:00 PM
Location: Whittemore 654 (6th Floor Conference Room)

Abstract:

This presentation is on analysis of different topology of transformer feedback LNAs. At millimeter wave frequency gain of the transistors is poor and noise becomes high as it operates near cutoff frequency. Series-series inductive degeneration LNA is popular where input matching is provided by inductive source degeneration. However the feedback, induced by source inductor, leads to a lower dynamic range upon gate to source voltage, thus reducing overall gain, especially at high frequencies. Gm boosted technique can be applied to boost the gain. Active circuits degrades the performance at high frequencies. Different kind of transformer feedback LNAs are analyzed to boost the gain and lower the noise figure. They can be also useful for broadband application. Transformers are passive circuits and easy to implement at high frequencies. With transformer feedback, similar impedance matching and noise matching can be obtained with greater flexibility.

Speaker Bio:

Sadia Afroz received her B.Sc degree in Electrical engineering from Bangladesh University of engineering and Technology, Bangladesh in 2011.She is currently working towards PhD degree in electrical engineering at Virginia tech. She is working on millimeter wave Phased array transceiver system. Her research interest includes RF and millimeter wave integrated transceivers and imaging systems.