Lens Antennas: Fundamentals and Present Applications
IEEE Malaysia Antenna Propagation / Microwave Theory Technique / Electromagnetic Compatibility (AP/MTT/EMC) Joint Chapter in collaboration with the Faculty of Electronic Engineering Technology (FTKEN) Universiti Malaysia Perlis (UniMAP), IEEE UniMAP Student Branch, and IEEE UTM Student Branch would like to invite you to the AP/MTT/EMC Webinar Series 1/2022, as follows:
Date : 26 January 2022 (Wednesday)
Time : 3.00 pm – 5.00 pm (MYT, GMT +8)
Speaker: Professor Oscar Quevedo-Teruel
Title: Lens Antennas: Fundamentals and Present Applications
Lens antennas are commonly englobed in a more general type of antennas, named aperture antennas. As their name indicates, they make use of a lens to modify the field distribution at the aperture of the antenna, which is typically fed by a single source. The lens is employed to transform the waves arriving from the source into a desired radiation pattern. Commonly, the desired radiation pattern is a directive beam in a given direction. However, like arrays, reflectors or leaky wave antennas, the goal changes depending on the application. For example, other desired features may be to produce multiple beams, or a broad beam-width.
Lenses were more commonly employed in optical applications. For this reason, most of the nomenclature comes from optics, and they are evaluated with rays theory. In this sense, the performance of the lens is conventionally described in terms of aberrations. An aberration is a failure of the rays to converge at the desired focus. This failure must be due to a defect or an improper design. Aberrations are classified as chromatic or monochromatic, depending on whether or not they have a frequency dependence. There are five monochromatic aberrations: spherical aberration, coma, astigmatism, Petzval field curvature, and distortion. However, this is not a common nomenclature for antenna designers in the radio-frequency and microwave regimes. In these regimes, the rays are substituted by electromagnetic fields, and the designers evaluate their antennas in terms of directivity, gain, efficiency, side lobe levels, cross polarization levels, etc. Therefore, there is a communication gap between both communities: optics and microwaves. In the THz regime, which is in between these two communities, researchers must understand both nomenclatures
In this talk, I will explain the operation of lens antennas, their potential, and two innovative techniques that have become very important in recent years. The first technique is transformation optics, which can be employed to produce three-dimensional directive lenses. The second one is metasurfaces, which can be used to produce low-cost and planar two-dimensional lenses. In the case of metasurfaces, fully metallic solutions are possible, which is a clear advantage in terms of losses. However, with the available technology, metasurfaces are only able to scan in one single plane. Finally, we introduce the concept of higher symmetries, that can be employed to enhance the bandwidth of conventional metasurfaces, or to increase their equivalent refractive indexes.
Oscar Quevedo-Teruel is a Senior Member of the IEEE. He received his Telecommunication Engineering and Ph.D. Degrees from Carlos III University of Madrid, Spain in 2005 and 2010. From 2010-2011, he joined the Department of Theoretical Physics of Condensed Matter at Universidad Autonoma de Madrid as a research fellow and went on to continue his postdoctoral research at Queen Mary University of London from 2011-2013.
In 2014, he joined the Division for Electromagnetic Engineering in the School of Electrical Engineering and Computer Science at KTH Royal Institute of Technology in Stockholm, Sweden where he is a Full Professor and Director of the Master Programme in Electromagnetics Fusion and Space Engineering. He has been an Associate Editor of the IEEE Transactions on Antennas and Propagation since 2018, a member of the Editoral Board of Nature Scientific Reports since 2021, and the founder and editor-in-chief of the EurAAP journal Reviews of Electromagnetics since 2020. He was the EurAAP delegate for Sweden, Norway, and Iceland from 2018-2020, and he has been a member of the EurAAP Board of Directors since January 2021. Since January 2022, he is the vice-chair of EurAAP. He is a distinguished lecturer of the IEEE Antennas and Propagation Society for the period of 2019-2022, and Chair of the IEEE APS Educational Initiatives Programme since 2020.
He has made scientific contributions to higher symmetries, transformation optics, lens antennas, metasurfaces, leaky wave antennas and high impedance surfaces. He is the co-author of 110 papers in international journals and 160 at international conferences.
For more details, kindly refer to the attached poster. An e-certificate will be provided to attended participants only.
Azremi Abdullah Al-Hadi, D.Sc (Tech)
IEEE Malaysia AP/MTT/EMC Joint Chapter
2020 IEEE AP-S Outstanding Chapter Award