Presenter

Mr Alaaeldien Medra - ETRO, Vrije Universiteit Brussel en IMEC

Abstract

With many emerging applications in the fields of road safety, smart homes and person detection, there is an increasing demand for cheap and ubiquitous accurate motion-detection radar sensors. The continuous-wave (CW) radar scheme is preferred for such applications as it uses constant envelope modulations, thus maximizing the power efficiency and the output power of the transmit part of the radar. Moreover, CW radar does not have a blind range as in pulsed radar. Exploiting the mm-wave frequency range improves the radar resolution for range and speed detection, thanks to the wide available bandwidth (BW) and the high carrier frequency, respectively. For the implementation of the chips needed for mm-wave radar, SiGe BiCMOS and GaAs technologies dominate the product scene. However, for small form factor and power-efficient sensors, CMOS is a better candidate as this technology allows for a co-integration of the analog and digital parts on one chip.
We propose a phase-modulated CW (PMCW) radar architecture, which is a digital-intensive architecture that allows for a more power efficient implementation in nanoscale CMOS technology. In this thesis, we tackle the main challenges in achieving a high-resolution PMCW radar sensor. From the receive side, implementing a highly linear front-end is one of the main issues together with finding a way to suppress the leakage from the transmitter to the receiver. This leakage is due to the fact that in CW radars, both the transmitter and receiver operate at the same time within the same frequency band.
First, we describe two implementations of a low-noise amplifier (LNA), operating at 79 GHz, which we realized in 28 nm CMOS. The two designs achieve a state-of-the-art performance, and a record noise figure and compression point. Then, we present an 80 GHz LNA with cancellation of the transmit leakage. The circuit achieves a cancellation of 27.5 dB, with minor degradation of the noise figure and gain of the LNA. Finally, we present the implementation of a 140 GHz power amplifier. Operating at such high frequency, mainly intended for indoor radar applications, allows the integration of the antenna on-chip, which results in a more compact radar sensor.

Short CV

Master of Science in Microelectronics System Design