Reconfigurable Low-Noise Amplifier Using RF MEMS-CMOS Varactors in 180 nm Technology

Abstract

Mobile phones are one of the most commonly used wireless communication devices. Users show high interest in multifunctional devices that can provide different kinds of services for exchanging information. Therefore, new wireless communication standards are introduced to satisfy the user's needs. Radio Frequency (RF) circuits such as Low Noise Amplifiers (LNA) are classically designed to operate at a single frequency band. With increasing demands for new wireless standards, wireless communication devices are required to have a dedicated RF circuit for each application. In order to reduce the occupied real estate and power consumption of the electronic circuits, it is recommended to replace parallel architectures that are used to provide multi-standard receivers by one architecture that is able to operate over multiple frequency bands. The LNA is one of the components in RF circuits that can be redesigned to operate over a wider frequency range. This thesis proposes a frequency-reconfigurable narrow-band LNA based on inductively degenerated configuration topology whose frequency of operation has beed varied by changing the capacitance value of the Radio Frequency Micro Electro-Mechanical System-Complementary Metal-Oxide Semiconductor (RF MEMS-CMOS) varactor. A novel RF MEMS-CMOS varactor design with 89% tuning range with a minimum capacitance of 1 pF and a maximum capacitance of 2 pF is designed in 180 nm CMOS technology from Taiwan's Semiconductor Manufacturing Company (TSMC) to be used in the LNA in order to achieve reconfigurability. The LNA was designed in 180 nm CMOS technology using an IBM process. The simulation results of the designed reconfigurable narrow-band LNA show a gain of 12 dB and a return loss of less than −20 dB over the tuning range from 800 MHz to 1100 MHz. Moreover, the LNA remains stable and obtaines the noise figure of less than 1 dB over the desired frequency range.