Since high data rates are necessary in optical communication systems, M-ary amplitude shift keying (ASK) has been developed to improve the spectral efficiency. The spectral efficiency is measured in terms of bits per second per hertz (bps/Hz) and is determined by the bandwidth. Thus, M-ary ASK allows higher data rate transmissions at a lower bandwidth to carry multiple data bits in a single symbol. In this project, MCML logic is utilized to implement M-ary ASK transmitter, which consists of an encoder, a D-Flip flop, a signal generator, and a laser driver. The differential topology is employed in all circuits to stabilize current ripple in the power supply and to operate in high-speed.
Low Noise Amplifier with Air-suspended RF MEMS Inductors
This work presents the development of a CMOS Ultra-wideband differential Low Noise Amplifier with air-suspended MEMS inductors substituting standard planar spiral inductors. Air-suspended MEMS inductors offer higher quality inductance factor and higher self-resonant frequency of operation when compared to monolithic spiral planar inductors. This extends the capabilities of a mixed-signal CMOS process, allowing for a high gain, full spectrum, 3.1 - 10.6GHz UWB Low Noise Amplifier. This is in collaboration with Dr. JB Lee's group at UT Dallas.
Ultra-Wideband Wireless Communication ICs
In current wireless communication applications, high data rate, low power, and low cost are desirable because of the surging demand for enhanced performance, battery-life, and cost efficiency of the electronic devices. To satisfy the above requirements, UWB technologies in 3.1-10.6 GHz band for communication systems with the average power emission restriction of -41.3 dBm/MHz has been adopted. Among different types of UWB systems, the impulse-radio UWB (IR-UWB) has been demonstrated to be low power, low cost, and highly immune to multipath fading, due to its less complicated carrier-free architecture and very low transmitting duty-cycle nature. In this project, CMOS integrated circuits has been developed for UWB communication systems.
Ultra-Wideband Radar SoC Development
The 22-29 GHz UWB automotive radar is defined as the short range radar (SRR) which can be operated with high range resolution and find the applications such as anti-collision sensing, adaptive cruise control (ACC) support, blind spot diction, and parking aid. In this work, the impulse radio UWB (IR-UWB) method is used to directly generate the transmitting pulses without employing any oscillator for low power consumption. The IR-UWB radar system on a chip has been developed using CMOS technology.
Glucose Sensing Readout Circuit
In amperometric glucose sensors, electrical current is generated as a result of chemical reaction between glucose molecules and sensor electrodes, and this current is then measured by the readout circuit. Current generated by this reaction is proportional to the concentration of glucose. In order to measure the glucose concentration level accurately, the CMOS readout circuit for amperometric sensors are developed to provide the wide input current range, linear output, and low power consumption.
In Situ Sensing System for Bilogical Toxin in HABs
The increasing occurrence of harmful algal blooms (HABs) in water resources worldwide is alarming the environmental and health authorities because of their potential to release lethal biological toxins, in particular, microcystins (MCs) produced from cyanobacterial HABs. To detect MCs, it is required to develop a highly sensitive optical sensors. Our work is focused on the development of the readout circuit for the optical sensors.