Advanced Antenna Systems for Fully Polarimetric Radar in Automotive Scenario
Doctoral thesis, 2024

The increasing dependence on Advanced Driver Assistance Systems (ADAS)
highlights the critical need for fast target recognition, effective collision avoidance, cruise control, lane assistance, etc. This necessitates a significant advancement in sensor technology, particularly for accurate target classification
and road surface sensing. In this context, automotive radar systems, especially
fully polarimetric radars, play a crucial role due to their superior capability
in detecting low radar cross-section in all weather conditions.
This thesis focuses on developing an advanced antenna system optimized for
fully polarimetric automotive radar applications. The design criteria for these
antennas include high polarimetric performance, compact size, high efficiency,
seamless integration in the system, and cost-effectiveness suitable for mass
production. In response to these requirements, we present several 77 GHz
advanced antenna designs for various automotive polarimetric radar systems.
Employing gap waveguide technology, we have developed two single-layer
dual circularly polarized antenna arrays and one single-layer circularly polarized antenna array, each designed specifically for automotive radar applications. The first model is an 8x1 array with dual circular polarization, featuring
a wide impedance bandwidth, 11% axial ratio bandwidth, high port isolation
(18.6 dB), and moderate gain (14.8 dBi). The second model, an 18x8 seriesfed planar array, utilizes the leaky-wave principle to achieve a bandwidth of
approximately 3.9%, a gain of 27.3 dBi, and port isolation exceeding 17.5 dB.
The third model is a single circularly polarized antenna, designed for easy
integration with radar systems. It achieves high port isolation (≥ 35 dB)
for adjacent receiver channels, reducing mutual couplings through thin decoupling walls and dummy elements. This antenna offers an impressive field of
view, with an embedded axial ratio (E-AR) below 3 dB within the azimuth
plane, covering approximately ±60◦ at the receiver and ±50◦ at the transmitter. Additionally, this antenna system has been integrated into a radar
front-end, with measurement results indicating enhanced detection from low
radar cross-section targets.
This thesis provides a comprehensive exploration of the design concepts,
including comparative analyses and interpretation of results. The simplicity,
low loss, and cost-effectiveness of these antenna designs make them viable for
widespread applications in both academic research and industrial settings.

circular polarization

gap waveguide

Antenna

dual circular polarization

automotive radar

polarimetric radar

Opponent: Professor Ying Liu

Author

Zhaorui Zang

Chalmers, Electrical Engineering, Communication, Antennas and Optical Networks

Zhaorui Zang, Ashraf Uz Zaman, Jian Yang, Carlo Bencivenni, Konstantinos Konstantinidis, “Single Layer Dual Circularly Polarized Antenna Elements for Automotive Radar at 77 GHz”. 2021 15th European Conference on Antennas and Propagation, March, 2021.

Zhaorui Zang, Ashraf Uz Zaman, Jian Yang, “Single Layer Dual Circularly Polarized Antenna Array Based on Ridge Gap Waveguide for 77 GHz Automotive Radar”. Published in IEEE Transactions on Antennas and Propagation, July. 2022.

Zhaorui Zang, Ashraf Uz Zaman, Jian Yang, “Design of Dual Circularly Polarized Inclined Slot Pair Based on Stepped-Height Ridge Gap Waveguide with Series Excitation”. 2022 16th European Conference on Antennas and Propagation, March, 2022.

Zhaorui Zang, Ashraf Uz Zaman, Jian Yang, “Single-Layer Dual-Circularly Polarized Series-Fed Gap Waveguide-Based Slot Array for a 77 GHz Automotive Radar”. Published in IEEE Transactions on Antennas and Propagation, May. 2023.

Zhaorui Zang, Qiannan Ren, Ashraf Uz Zaman, Jian Yang, “77-GHz Fully Polarimetric Antenna System with Circularly Polarized Slots in Gap Waveguide for Automotive Radar”

In this doctoral research, we've developed an automotive radar antenna system that marks a significant advancement in road safety technology. This system incorporates three innovative antennas and features dual circular polarizations for both transmission and reception. This design greatly improves the radar's ability to detect low Radar Cross-Section (RCS) targets, such as bicycles and scooters, which are often difficult for traditional systems to spot.

The importance of our work extends to enhancing road safety. By increasing radar sensitivity, we aim to reduce traffic accidents and provide better protection for vulnerable road users, contributing to safer urban environments.

Looking ahead, the potential applications of our research go beyond automotive safety. The enhanced sensitivity of our radar system suggests its usefulness in other fields, such as surveillance and environmental monitoring. As technology progresses, our research contributes valuable insights into the evolving landscape of radar and sensor systems, offering new opportunities for improving safety and monitoring in various sectors.

Hardware For Next generation Millimeter Wave Automotive Radar Sensor

VINNOVA (2018-02707), 2019-01-01 -- 2022-12-31.

Areas of Advance

Information and Communication Technology

Roots

Basic sciences

Driving Forces

Innovation and entrepreneurship

Subject Categories

Electrical Engineering, Electronic Engineering, Information Engineering

ISBN

978-91-8103-007-5

Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 5465

Publisher

Chalmers

Opponent: Professor Ying Liu

More information

Latest update

2/9/2024 8