CMOS Variable Gain Low Noise Amplifier for Radio Frequency Applications

The evolution of wireless telecommunication systems is expanding in an unprecedented way and such developments have prompted many design challenges specifically for low cost and low power System-on-Chip (SoC). In order to fulfill these needs, the design challenges need to be seen from all levels...

Full description

Saved in:

Bibliographic Details
Main Author:	Lee, Lini
Format:	Thesis
Language:	English English
Published:	2008
Subjects:	Radio frequency
Online Access:	http://psasir.upm.edu.my/id/eprint/5469/1/FK_2008_73a.pdf
Tags:	Add Tag No Tags, Be the first to tag this record!

id	my-upm-ir.5469
record_format	uketd_dc
spelling	my-upm-ir.54692013-05-27T07:23:04Z CMOS Variable Gain Low Noise Amplifier for Radio Frequency Applications 2008 Lee, Lini The evolution of wireless telecommunication systems is expanding in an unprecedented way and such developments have prompted many design challenges specifically for low cost and low power System-on-Chip (SoC). In order to fulfill these needs, the design challenges need to be seen from all levels of the wireless system design from architecture, circuit and the process technology. The first stage of a receiver is the radio frequency (RF) input with low noise amplifier (LNA) as the first building block. Hence, it dominates the performance of the receiver system especially in noise and sensitivity. An LNA which incorporates a variable gain stage is useful in the receiver system in order to achieve continuous gain controllability which can be used to prevent saturation in the receiver when the input signal becomes relatively large compared to the power supply. Thus, circuit solutions of current mirror, gain control loop, capacitively coupled scheme and parallel inter-stage resonance are proposed. On-chip inductors are needed in a LNA to fulfill its requirements of noise and input matching. Therefore, spiral inductors are designed, analyzed and implemented according to the specifications. The main key part of this thesis describes the designs of the variable gain LNA (VGLNA) for low power consumption, continuous gain control and high selectivity over a wide frequency band with the target applications of frequency band at 2.0, 2.4, 5.0, 5.7 and 8 GHz. The VGLNA utilizes current mirror which allows precise copying of the current independent of temperature. With an adequate biased voltage applied, continuous gain control of approximately 28 dB is achieved at low current without degrading the noise performance of the VGLNA significantly, maintaining it below 2 dB. Second approach proposes the capacitively coupled LNA which ensures that the minimum required voltage supply for this topology is only one threshold voltage and not doubled the amount though it is a cascode transistors structure. Hence with these two innovative approaches, the power dissipation of the LNA would be minimal. Continuous gain control is achieved with the gain control loop and current mirror methods. By introducing a simple gain control loop composed of a gain control transistor and a capacitor, a wide continuous gain tuning range is achieved and with the current mirror, the VGLNA has continuous controllability of the gain. A new circuit structure named parallel inter-stage resonance LNA is proposed and it offers high selectivity of gain over the 5 GHz frequency band while keeping the noise figure below 2 dB. The simulation results meet the desired specifications and the measurement results of transistors and inductors are shown to be comparable with the analytical results. Finally, it can be concluded that the VGLNA designs have shown continuous controllable gain and low noise with low power consumption, not forgetting high selectivity over a wide frequency band. Radio frequency Amplifier, Radio frequency 2008 Thesis http://psasir.upm.edu.my/id/eprint/5469/ http://psasir.upm.edu.my/id/eprint/5469/1/FK_2008_73a.pdf application/pdf en public phd doctoral Universiti Putra Malaysia Radio frequency Amplifier, Radio frequency Faculty of Engineering English
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English English
topic	Radio frequency Radio frequency
spellingShingle	Radio frequency Radio frequency Lee, Lini CMOS Variable Gain Low Noise Amplifier for Radio Frequency Applications
description	The evolution of wireless telecommunication systems is expanding in an unprecedented way and such developments have prompted many design challenges specifically for low cost and low power System-on-Chip (SoC). In order to fulfill these needs, the design challenges need to be seen from all levels of the wireless system design from architecture, circuit and the process technology. The first stage of a receiver is the radio frequency (RF) input with low noise amplifier (LNA) as the first building block. Hence, it dominates the performance of the receiver system especially in noise and sensitivity. An LNA which incorporates a variable gain stage is useful in the receiver system in order to achieve continuous gain controllability which can be used to prevent saturation in the receiver when the input signal becomes relatively large compared to the power supply. Thus, circuit solutions of current mirror, gain control loop, capacitively coupled scheme and parallel inter-stage resonance are proposed. On-chip inductors are needed in a LNA to fulfill its requirements of noise and input matching. Therefore, spiral inductors are designed, analyzed and implemented according to the specifications. The main key part of this thesis describes the designs of the variable gain LNA (VGLNA) for low power consumption, continuous gain control and high selectivity over a wide frequency band with the target applications of frequency band at 2.0, 2.4, 5.0, 5.7 and 8 GHz. The VGLNA utilizes current mirror which allows precise copying of the current independent of temperature. With an adequate biased voltage applied, continuous gain control of approximately 28 dB is achieved at low current without degrading the noise performance of the VGLNA significantly, maintaining it below 2 dB. Second approach proposes the capacitively coupled LNA which ensures that the minimum required voltage supply for this topology is only one threshold voltage and not doubled the amount though it is a cascode transistors structure. Hence with these two innovative approaches, the power dissipation of the LNA would be minimal. Continuous gain control is achieved with the gain control loop and current mirror methods. By introducing a simple gain control loop composed of a gain control transistor and a capacitor, a wide continuous gain tuning range is achieved and with the current mirror, the VGLNA has continuous controllability of the gain. A new circuit structure named parallel inter-stage resonance LNA is proposed and it offers high selectivity of gain over the 5 GHz frequency band while keeping the noise figure below 2 dB. The simulation results meet the desired specifications and the measurement results of transistors and inductors are shown to be comparable with the analytical results. Finally, it can be concluded that the VGLNA designs have shown continuous controllable gain and low noise with low power consumption, not forgetting high selectivity over a wide frequency band.
format	Thesis
qualification_name	Doctor of Philosophy (PhD.)
qualification_level	Doctorate
author	Lee, Lini
author_facet	Lee, Lini
author_sort	Lee, Lini
title	CMOS Variable Gain Low Noise Amplifier for Radio Frequency Applications
title_short	CMOS Variable Gain Low Noise Amplifier for Radio Frequency Applications
title_full	CMOS Variable Gain Low Noise Amplifier for Radio Frequency Applications
title_fullStr	CMOS Variable Gain Low Noise Amplifier for Radio Frequency Applications
title_full_unstemmed	CMOS Variable Gain Low Noise Amplifier for Radio Frequency Applications
title_sort	cmos variable gain low noise amplifier for radio frequency applications
granting_institution	Universiti Putra Malaysia
granting_department	Faculty of Engineering
publishDate	2008
url	http://psasir.upm.edu.my/id/eprint/5469/1/FK_2008_73a.pdf
_version_	1747810432504037376

CMOS Variable Gain Low Noise Amplifier for Radio Frequency Applications

Similar Items