Spline-Shaped Microstrip Edge-Fed Antenna for Automotive Radar Systems Operating at 77 GHz

Core Concepts

An innovative single-layer, horizontally-polarized, millimeter-wave microstrip edge-fed antenna with a spline-shaped radiator profile is designed and optimized for 77 GHz automotive radar applications.

Abstract

The content presents the design and optimization of an innovative millimeter-wave microstrip edge-fed antenna (EFA) for 77 GHz automotive radar systems. The key features of the proposed antenna are: Single-layer layout with a horizontally-polarized radiation pattern, meeting the requirements for automotive radar applications. The radiator contour is modeled using a spline-shaped (SS) profile, which provides a flexible and efficient way to control the antenna's electromagnetic performance. The SS-EFA is designed and optimized using a customized implementation of the System-by-Design (SbD) paradigm, which enables a computationally efficient global optimization. The synthesized SS-EFA is integrated within a linear arrangement of identical replicas to account for the integration into a real radar system. The antenna exhibits suitable impedance matching, isolation, polarization purity, and stability of the beam shaping/pointing within the 76-78 GHz target band. The reliability of the full-wave simulation results is assessed through experimental validation on a printed circuit board (PCB)-manufactured prototype, confirming the suitability of the SS-EFA for automotive radar applications.

Stats

The antenna has an operating frequency band of 76-78 GHz. The reflection coefficient, S11, is less than -10 dB within the target band. The sidelobe level (SLL) is less than -15 dB. The half-power beamwidth (HPBW) is less than 18 degrees. The beam direction deviation (BDD) is less than 2 degrees. The polarization ratio (PR) is greater than 20 dB.

Quotes

"The radiator is designed under the main requirements of having (i) an horizontally-polarized pattern and (ii) a single-layer layout." "The flexibility of the proposed modeling approach enables an accurate control of the feeding phases within the operative band." "The continuous non-uniformity of the radiator width allows one to optimize the elevation FF features including a lowering of the sidelobe level (SLL), which is beneficial for reducing both near range clutter from the road surface and the multi-path interferences."

Key Insights Distilled From

Spline-Shaped Microstrip Edge-Fed Antenna for 77 GHz Automotive Radar Systems

by Marco Salucc... at arxiv.org 05-07-2024

https://arxiv.org/pdf/2208.00841.pdf

Deeper Inquiries

How can the proposed spline-shaped antenna design be extended to other frequency bands or applications beyond automotive radars?

The proposed spline-shaped antenna design can be extended to other frequency bands or applications by adjusting the dimensions and parameters of the antenna to resonate at different frequencies. Since the design is based on a flexible spline profile with a reduced set of geometric descriptors, it can be easily modified to operate at various frequencies within the millimeter-wave range or even at lower frequencies. By optimizing the control points of the spline curve and adjusting the feeding mechanism, the antenna can be tailored to meet the requirements of different frequency bands or applications. Additionally, the single-layer layout and horizontal polarization characteristics of the antenna make it suitable for a wide range of radar and communication systems beyond automotive radars.

What are the potential limitations or drawbacks of the spline-shaped approach compared to other antenna modeling techniques?

While the spline-shaped approach offers flexibility and simplicity in modeling complex antenna geometries, it may have some limitations compared to other antenna modeling techniques. One potential drawback is the increased computational complexity involved in optimizing the control points of the spline curve, especially for designs with a large number of degrees of freedom. This can result in longer optimization times and higher computational resources required for the design process. Additionally, the smooth and continuous profile of the spline may limit the sharpness of antenna features such as beam shaping or sidelobe suppression, which could be better achieved with other antenna structures like horn antennas or reflector antennas. Furthermore, the manufacturing process of spline-shaped antennas may be more challenging and less standardized compared to traditional antenna designs, potentially leading to higher production costs and complexity.

How could the antenna's performance be further improved, for example by exploring different feeding mechanisms or integrating it with other radar components?

To further improve the antenna's performance, several strategies can be explored. One approach is to investigate different feeding mechanisms, such as aperture coupling or proximity coupling, to enhance the antenna's efficiency and impedance matching. By optimizing the feeding structure and location, the antenna's radiation characteristics can be improved, leading to better overall performance. Additionally, integrating the antenna with other radar components, such as low-noise amplifiers or phase shifters, can enhance the system's functionality and capabilities. By carefully designing the integration of these components with the antenna, factors like mutual coupling and impedance matching can be optimized, resulting in a more efficient and reliable radar system. Furthermore, exploring advanced materials or manufacturing techniques to reduce losses and improve the antenna's bandwidth can also contribute to enhancing its performance in real-world applications.