UROP Proceedings 2022-23

School of Engineering Department of Electronic and Computer Engineering 136 Design of Radio-frequency Integrated Circuits Supervisor: LUONG, Howard Cam / ECE Student: WANG, Jiajun / ELEC Course: UROP1100, Spring This report aims to specify how to design a CMOS low-power low-supply amplifier with a differential input and a single-ended output and to verify it using SPICE simulation. It will be illustrated in the order of motivation, model chosen, calculation and simulation. There exist many amplifier topologies, and it is important to choose the right one. The main challenge is the low-power requirement. Also, high output gain and output swing are other concerns. The design can’t be done in first try. In a typical IC design cycle, the design parameters need to be optimized and tuned, and the design process needs to be iterated until all the specifications are met simultaneously. An Optofluidic Biological Cell Stretcher Supervisor: POON, Andrew Wing On / ECE Student: ZHANG, Yixuan / ELEC Course: UROP1100, Fall UROP2100, Spring The elasticity of the cells is an important indicator of cell’s physiological activity. Most of the current mainstream measurement methods require mechanical stretching. Such direct external force intervention on cells may cause cells to lose their original properties. So, we are going to develop a new cell-stretcher using optical tweezers and a microfluidic channel, which can avoid direct contact with the cells. The cells would be trapped at the focus of a laser beam while flowing through the channel. Under the balance of the optical gradient force and the fluidic force, the cells would be stretched, allowing us to quantify their elasticity using the degree of deformation. An image processing tool was developed to analyze the location of the focus point of the single laser-beam trap automatically, to track the cells and to detect possible rotations during their translational motions based on the two-dimensional images, and eventually to extract the cell deformation. We also attempted to develop line optical tweezers, which could trap cells more efficiently with potentially a lower power density. Silicon Photonic Switch Components on a Chip Supervisor: POON, Andrew Wing On / ECE Student: ZHANG, Yixuan / ELEC Course: UROP1000, Summer Silicon-on-insulator (SOI) microring resonator has long been used as an optical channel frequency filter. In our application, we aimed to obtain a large free spectral range (FSR) of exceeding 60 nm at 1550 nm telecommunications wavelengths. Rather than using a single microring resonator, which requires a microring radius of about 1 mm and can cause an excess waveguide bending loss, we adopted the Vernier effect. By using two microrings with slightly different radius, we aimed to expand the FSR significantly. We demonstrated an initial design of a double-microring-resonator Vernier filter. To enable the resonance wavelength to be swept over a wide spectral window, we designed an PIN diode structure to electro-optically tune the Vernier filter. We discussed the numerically modelled tuning behaviour of the resonators.