In SHINE, we aim to merge applied electromagnetics and integrated circuits/systems design to establish a cohesive research theme that enables the development of innovative circuits/systems for a wide range of applications.
Here are some examples of our current projects:

• In-band full duplex systems

  

  This research provides an innovative solution to a critical problem in simultaneous transmit and receive (STAR) communication and radar systems. In this research, our main focus is to address the significant issue of self-interference, a problem often leading to receiver nonlinearity and saturation. To address this challenge, we have designed a new active low-noise circulator in conjunction with a quadrature-fed antenna. This structure results in circular polarized radiation of the transmitting signal, segregating the echo and self interference (SI) signals, and significantly attenuating the SI. As a proof of concept, the proposed SI cancellation configuration is designed for a 77-81 GHz FMCW radar system sharing Tx/Rx antenna, and the radar’s performance verifies the superiority of the introduced technique.

• Wearable Electronics

  

  Wearable technology is becoming popular in medical fields, enabling an early detection of various diseases such as sleep disorders. Sleep apnea, a significant sleep disorder, presents challenges due to expensive diagnostic methods. To address this, a novel wireless wearable system has been developed which captures bio-signals and transmits them to a smartphone, allowing for a low-cost sleep apnea diagnosis. The system uses readily available components and records eight signals, including movement and Photoplethysmography (PPG) data. These signals are correlated with vital signs using an advanced signal processing, allowing for an impressive accuracy of 90.2% in apnea and hypopnea events detection. The resulting accuracy is further improved using sensor fusion techniques, reaching 95.1% for total apnea and hypopnea events, and nearly 98% for the Apnea-Hypopnea Index (AHI), maintaining an average reliability rate of approximately 93%.

• Ultra-low-power electronics

  

  There is an increasing demand for ultra-low-power electronic systems to extend the battery life of portable devices, implantable biomedical instruments, and wearable health monitoring systems. Low-power and low-voltage systems also allow for the operation of wireless IoT devices through energy harvesting. This research presents two novel, low-noise, low-voltage, and energy-efficient amplifiers with high CMRR that can be used for portable or implantable biopotential acquisition systems such as implantable ECG and brain electrical activity monitoring microsystems.

• low-power low-complexity hight-speed wireline transceivers

  

  To catch up with the escalating network traffic and to meet the ever-growing demand for high data rates in wireline communication systems while enhancing their power efficiency, we have offered several solutions in our group, a couple of which are outlined below:

  • We have introduced a novel signaling method (communication protocol) which is based on a Nyquist-rate orthogonal pulse amplitude modulation scheme. This innovative signaling approach allows for a high-rate data transmission and a high quality (with low sensitivity to noise and jitter) data reception while reducing the power consumption of wired transceivers. This efficiency is derived from the unique structure of the proposed signaling which eliminates the need for complex equalizers and clock and data recovery (CDR) circuits and allows for a simple implementation of the entire TRx using low-power integrated circuits.

  • Our group has also proposed a novel wireline communication system which incorporates a new oscillator allowing for precise control of both loop frequency and individual clock phases. This system is notable for its compact size and low power consumption.

• High-resolution vector modulators for communications and radars

  

  We have developed a low-power phase shifter with an independent control over both phase and amplitude of its output signal. This versatile phase shifter can be utilized to adjust clock pulse phases in wireline transceivers, as well as to independently control the phase and amplitude of excitation signals in phased array systems. With a 360-degree phase tuning range, compact size, minimal power consumption, and a simple control interface, this phase shifter is an excellent choice for 5G networks and low-power wireline communication systems.

• novel beamforming/steering methods

  

  Beamforming and steering, which have been typically achieved using phased array antennas, allow for mitigating the propagation loss of energy and are essential in modern communication and radar systems. This work introduces an innovative technique based on superimposing circular waveguide TEn1 modes for circular polarized beamforming and 360° beam steering. A remarkable advantage of this method is its realization using a single relatively compact antenna structure. This beamforming/steering antenna has potential applications in user mobile devices, base stations, repeaters, and radars. Moreover, owing to its circular polarized radiation, it offers improved immunity to issues like multipath fading and multiple reflections and eliminates the need for Tx and Rx precise antenna alignment.

• low-power low-temperature-coefficient oscillators

  

  The growth of demand for autonomous vehicles and higher data rates in communication protocols and hardware interfaces like CAN bus and USB has raised the need for stable clock sources maintaining low temperature coefficient (TC) over a wide temperature range (e.g. from -20°C to +100°C). Additionally, a robust oscillator consuming a very low amount of power is also crucial in wearables, network sensors, and IoT. Traditionally, temperature-dependent frequency variation has been mitigated using off-chip components, but this approach comes at the cost of increased size and power consumption. The main objective of this research is to design an integrated low-power oscillator that ensures a consistent frequency despite temperature changes.

• Integrated harmonic rejection mixers

  

  The increasing demand for wideband and multi-standard radio systems and the desire to minimize the number of high-frequency filters in radio systems have driven our motivation to design harmonic rejection mixers. We intend to reduce the power consumption of these mixers by utilizing low-power multi-phase square wave generators. Such harmonic rejection mixers would be well-suited for 5G telecommunications applications.

• self-calibrating phased arrays

  

  Self-calibrating phased arrays are capable of autonomously calibrating and optimizing their performance without external calibration equipment or any manual adjustment. These arrays include multiple antenna elements that can dynamically adjust their excitation phase and amplitude settings to compensate for component variations, environmental changes, or other sources of interference. Integrated self-calibrating phased arrays offer significant advantages, but they also face several challenges, including high power consumption, large area, complex circuitry, and limited tuning range. In this project, we focus on developing a low-complexity, compact, and low-power self-calibrating phased array with a large tuning range to facilitate their commercial use.