Candidate: Mehran Hazer Sahlabadi
Date: April 16, 2026
Time: 2:00 PM
Location: Online
Supervisor: Prof. Slim Boumaiza
All are welcome!
Abstract:
The evolution of next-generation wireless systems has driven the adoption of large-scale antenna arrays to achieve higher data rates and improved spectral efficiency. However, operation at millimeter-wave frequencies introduces significant challenges, including increased losses, reduced efficiency, and stringent linearity requirements in RF front-end circuits. As a result, the design of compact and high-performance front-end building blocks is critical for scalable beamforming systems.
In this seminar, these challenges are addressed through circuit- and system-level design techniques targeting key components of beamforming front-ends.
First, a co-design methodology for the transmit/receive front-end is presented, in which the power amplifier, low-noise amplifier, and RF switch are jointly optimized and implemented in 45-nm SOI technology. This approach improves transmitter efficiency, reduces receiver noise, and enables compact broadband operation, overcoming key limitations of conventional TDD front-end architectures.
Second, a digitally controlled bidirectional variable-gain phase shifter is introduced, also implemented in 45-nm SOI technology, to provide precise amplitude and phase control required for beamforming. The proposed design achieves a wide gain tuning range with low gain and phase errors, enabling accurate and reliable beam steering in multi-beam wireless systems.
Finally, an analog predistortion technique is proposed to enhance power amplifier linearity. Unlike conventional approaches, the method remains effective across varying output power levels and modulation bandwidths, improving signal quality without relying on complex and power-intensive digital signal processing.
Overall, this work demonstrates scalable and energy-efficient circuit and system design strategies for next-generation beamforming front-ends, enabling high-performance wireless communication systems.