Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List

Full text release has been delayed at the author's request until June 01, 2025

ETD Abstract Container

Abstract Header

Wideband and Multi-Band Circularly Periodic High Impedance Surfaces Integrated With Wideband Spiral Antennas

Lele, Kshitij
http://orcid.org/0009-0000-2658-6431
http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1705006765970062

Abstract Details

2024, Doctor of Philosophy (PhD), Ohio University, Electrical Engineering (Engineering and Technology).
This dissertation presents four design methodologies for circularly periodic multi-band and wideband High Impedance Surfaces (HISs). The resulting HIS designs are integrated with wideband spiral antennas to demonstrate unidirectional multi-band and/or wideband performance. For many applications (e.g., Global Navigation Satellite Systems (GNSS)), antennas having unidirectional radiation patterns are desirable to provide good signal reception and to minimize multi-path reflections. Spiral antennas, due to their wideband nature, can be used to cover a wide range of frequency bands using a single antenna element. However, in order to make their radiation characteristics unidirectional, a conductive and/or lossy ground plane is often used. Typically, such types of wideband spiral antennas use a metallic cavity filled with Radio Frequency (RF) absorber material or a lossy magnetic type back-plane. These antennas will typically have an increased height profile or sacrifice gain, and/or multipath mitigation performance. This dissertation is focused on using an HIS (also called metamaterial) as a perfect magnetic conductor (PMC) ground plane, as opposed to common perfect electric conductor (PEC) ground planes. HISs can be a good alternative because they can be placed relatively close to the antenna while still preserving the 0° reflection-phase characteristics at the surface of the HIS. Most HISs proposed in literature use rectangular and tend to have a relatively narrow bandwidth and are often referred to as Frequency Selective Surfaces (FSS). It has been previously shown that for curvilinear radiating elements like spiral or loop antennas, better performance is achieved by using circularly periodic HISs. Using a cylindrical wave and concentric circular waveguides to model circularly periodic HISs provides a better approximation of sources with curvilinear radiating elements. In addition, most HISs proposed so far tend to have relatively narrow bandwidth because they are homogeneous in nature i.e., all unit cell patches (which are the building blocks of the HIS) and rings are designed to operate at the same frequency. To overcome these challenges, four HIS designs spanning either single or multiple wide frequency bands are presented. The first design presents a multi-band HIS designed to reflect in-phase in three distinct frequency sub-bands (1.3 GHz, 2.4 GHz, 5.8 GHz). Then a wideband spiral antenna is placed above the multi-band HIS and S11, bandwidth and radiation pattern plots are presented to demonstrate multi-band performance. The second design presents a broadband HIS with three distinct design frequencies (2.4 GHz, 3.5 GHz, 5.0 GHz) stitched together to form a contiguous broadband HIS. Each frequency sub-band is designed to have 0° reflection phase at the design frequencies. Broadband performance is obtained by using the ±90° reflection phase bandwidth metric to stitch all sub-bands together. Full performance of the HIS design is demonstrated by integrating the broadband HIS with the broadband spiral antenna (placed at a distance of 0.09λ, at the lowest operating frequency, above the HIS) and enclosing the final antenna structure in a cavity to obtain broadband unidirectional performance. The third design presents a progressive Ultra-wideband (UWB) HIS design methodology that covers a broad continuous range of frequencies ranging from 1.1 GHz to 8.0 GHz. The design methodology defines two zones: a heterogenous zone and a homogenous zone. In the heterogenous zone, each ring is designed to operate at a different frequency whereas in the homogenous zone all rings are designed to operate at the same frequency. A wideband spiral antenna is then integrated with the progressive UWB HIS and the full structure is enclosed in an aluminum cavity to demonstrate unidirectional UWB performance. The fourth design presents a GNSS multi-band HIS design methodology that is designed specifically for commonly used GNSS frequency bands including GPS, GLONASS, GALILEO, BeiDou, QZSS, and and GNSS applications in the 2.4-2.5 GHz band, such as NavIC at 2.49 GHz, for ranging and WiFi functionality in NavIC, and QZSS and BDS, respectively. In order to cover all applications, the presented design is multi-band with the first band in the 1.1 – 1.6 GHz range and the second band in the 2.4- 2.5 GHz range. To achieve this, the design methodology defines three zones: an innerhomogenous zone, a heterogenous zone, and an outer-homogenous zone. A wideband spiral antenna is then integrated with the GNSS progressive multi-band HIS to demonstrate unidirectional performance. This GNSS progressive multi-band HIS-backed spiral antenna is enclosed in an absorber-filled aluminum cavity to further suppress back lobe radiation.
Chris Bartone, Ph.D. (Advisor)
Michael Braasch, Ph.D. (Committee Member)
David Ingram, Ph.D. (Committee Member)
Sabrina Ugazio, Ph.D. (Committee Member)
Eric Stinaff, Ph.D. (Committee Member)
Savas Kaya, Ph.D. (Committee Member)
158 p.
Electrical Engineering; Electromagnetics
High Impedance Surfaces, Metamaterials, Spiral Antennas, broadband HIS, multi-band HIS, circularly periodic HIS, GNSS.

Recommended Citations

Citations

  • Lele, K. (2024). Wideband and Multi-Band Circularly Periodic High Impedance Surfaces Integrated With Wideband Spiral Antennas [Doctoral dissertation, Ohio University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1705006765970062

    APA Style (7th edition)

  • Lele, Kshitij. Wideband and Multi-Band Circularly Periodic High Impedance Surfaces Integrated With Wideband Spiral Antennas. 2024. Ohio University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1705006765970062.

    MLA Style (8th edition)

  • Lele, Kshitij. "Wideband and Multi-Band Circularly Periodic High Impedance Surfaces Integrated With Wideband Spiral Antennas." Doctoral dissertation, Ohio University, 2024. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1705006765970062

    Chicago Manual of Style (17th edition)

ohiou1705006765970062
© 2024, all rights reserved.
This open access ETD is published by Ohio University and OhioLINK.