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Resonant Cavity Antennas for 5G Communication Systems

  • Author / Creator
    Goudarzi, Azita
  • Demand of high traffic capacity and speed in wireless communication systems led to the fifth-generation (5G) technologies with high data rate, high reliability, and low power consumption over the millimeter-wave (mmW) spectrum.

    Recently, much attention has been focused on the design of multi-functional antennas, which have a combination of characteristics in one single structure for different applications. In fact, having a high-gain antenna featured with beam steering, circular polarization, switched beam, multiple radiation beams, or wide frequency band is desired. Such structures are highly required for the next communication systems, since they lead to lower cost, compact size and even lower power consumption. This thesis develops switched beam or steerable beam resonant cavity antennas (RCAs) with reasonable antenna gain as platforms for future multi-functional aperture antennas. The most focus of this thesis is to design antennas for small cell base stations and wireless sensor networks, where antennas with switching beam/ steering beam are required.
    As initial prototypes, two high-gain circular polarized (CP) RCA with wide frequency band are designed, fabricated and measured, which can be scaled for mmW 5G applications.

    Next, two high-gain mmW RCA with unidirectional frequency scanning characteristics are designed, fabricated and measured for 5G applications. A general design guideline is given by theoretical analysis of the RCA structures using the ray tracing method to formulate the beam steering functionality versus frequency over desired predetermined angles. The conventional structures of the RCAs tend to obtain a conical beam because of the intrinsic characteristics of the symmetric structures of the partially reflective surface (PRS) and the feed position. The realization of a RCA with unidirectional beam has been a challenge, which requires constructive modification of the conventional RCAs and is considered in these designs. Besides, a scenario is defined for the potential application of the designed antennas for 5G base stations. Also, to ensure that the designed antenna can meet the latest standards of 5G base stations, several criteria are investigated through some calculations.
    Finally, a technique to obtain a high-gain multi-beam antenna is proposed using the RCA structures. A thin single metallo-dielectric layer is used as the PRS layer to enhance the radiation performance of the entire structure and provide an off-axis pencil beam at an arbitrary elevation angle. A cylindrical cavity is designed using a right-angle-type semi-waveguide (RATSW) structure as the main radiator. To confirm the functionality of the proposed RCA, a prototype is fabricated with five coaxial probes to generate five radiation beams; however, the structure can be extended to more antenna beams by using higher number of probes. The cavity structure of the proposed antenna is fabricated by the three-dimensional (3D) printing technology as an easy manufacturing process. Also, a conceptional scenario for the potential applications of the proposed antenna in the 5G base stations is presented and discussed.

  • Subjects / Keywords
  • Graduation date
    Fall 2021
  • Type of Item
    Thesis
  • Degree
    Master of Science
  • DOI
    https://doi.org/10.7939/r3-6zqw-xm34
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.