24-28 GHZ MULTIMODE ANTENNA DESIGN

Date

2023-9-06

Author

Çevik, Ayşe Kübra

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In this thesis, characteristic mode theory and symmetry analysis are used to design an antenna array element operating in the 24-28 GHz frequency band with a VSWR less than 1:2. Although the targeted frequency range is between 24-28 GHz, a wider bandwidth is obtained between 24-31 GHz. It is the frequency band intended to be used for 5G small cell base stations. Four characteristic modes each with a distinct radiation pattern, are excited on the designed patch antenna. Furthermore, a novel and low-profile planar exciter technique is proposed to excite the characteristic modes. The proposed exciter is a printed balun structure. In order to excite four modes, these baluns are placed in the middle of each of the four edges of the patch antenna. Furthermore, rectangular and circular slits are etched on the square patch to achieve a wider bandwidth. As a proof of concept, a scaled version of the designed Ka -band antenna is produced and measured. The scaled version of the antenna works in the 2.3-3.2 GHz frequency band. Since its dimensions are larger than the Ka- band antenna, it can be produced quickly with the LPKF device. Additionally, a feed network consisting of rat-race couplers is also designed and manufactured to provide the necessary phase distributions to excite the characteristic modes of the antenna. Far-field pattern measurements of the C-band patch is taken at 2.7 GHz, and it is seen that distinct patterns are obtained for each mode. The designed antenna has a simple and low-profile design; thus, it can be utilized as a part of a massive MIMO base station for 5G mmWave applications.

Subject Keywords

Characteristic Modes, 5G mmWave, Wide-Band, MIMO Antenna Element, Square Patch Antenna, Printed Balun

URI

https://hdl.handle.net/11511/105610

Collections

Graduate School of Natural and Applied Sciences, Thesis