Thesis
Gain control and linearity improvement for low noise amplifiers in 5GHZ direct conversion receivers
Washington State University
Master of Science (MS), Washington State University
2005
Handle:
https://hdl.handle.net/2376/323
Abstract
The unprecedented growth in wireless technology has served to create an ever-increasing need for lower power, higher performance, and low cost receiver topologies. Apart from performance enhancement, recent times have also seen an increase in newer topologies catering to multi-mode receivers featuring reconfigurability. From multi-band to multi-gain, the spectrum is broad. Also with the advent and success of complementary metal oxide semiconductor (CMOS) technology, primarily owing to its economic feasibility, topological innovation is a hard requirement in order to match the performance standards set by high-performance technologies like GaAs and SiGe. CMOS technology has also made possible the creation of feasible System-On-a-Chip (SOC) solutions for higher integration needs. The need for multi-mode receivers is felt even more strongly with SOC solutions becoming more feasible. This dissertation explores the design of a multi-mode receiver front end component, viz. the Low Noise Amplifier (LNA). A LNA having a noise figure of 3.1dB, with dual-mode operation and a new integrated gain controllable on-chip active balun, have been designed in 0.25-um CMOS technology for a 5 GHz Industrial Scientific Medical (ISM) band direct conversion receiver (DCR). The circuit consumes 10mA of current in the high gain mode giving 20dB of gain while using 50% less power in the low gain mode and providing a gain of 12 dB. With the active balun having gain and phase mismatch within 0.5dB and 1 degree, respectively, the presented circuit is believed to be the first to integrate an LNA, gain controllability and an on-chip active balun, paving the way for higher silicon real estate efficiency in future designs. Measurement details for the LNA and active balun are presented and discussed. The thesis also explores the needs and theory behind receiver and LNA linearity. Different linearity enhancement techniques are discussed followed by the introduction of a novel enhanced third order transconductance (gm3) cancellation technique. An enhanced linearity LNA, designed using this technique is presented and analyzed. Advantages of this architecture are discussed and simulation results are shown along with the submitted layout.
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Details
- Title
- Gain control and linearity improvement for low noise amplifiers in 5GHZ direct conversion receivers
- Creators
- Mallesh Rajashekharaiah
- Contributors
- Deukhyoun Heo (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Electrical Engineering and Computer Science, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525007701842
- Language
- English
- Resource Type
- Thesis