College - Author 1
College of Engineering
Department - Author 1
Electrical Engineering Department
Degree Name - Author 1
BS in Electrical Engineering
College - Author 2
College of Engineering
Department - Author 2
Electrical Engineering Department
Degree - Author 2
BS in Electrical Engineering
College - Author 3
College of Engineering
Department - Author 3
Electrical Engineering Department
Degree - Author 3
BS in Electrical Engineering
College - Author 4
College of Engineering
Department - Author 4
Electrical Engineering Department
Degree - Author 4
BS in Electrical Engineering
College - Author 5
College of Engineering
Department - Author 5
Electrical Engineering Department
Degree - Author 5
BS in Electrical Engineering
Date
7-2026
Primary Advisor
Payam Nayeri, College of Engineering, Electrical Engineering Department
Additional Advisors
Steve Dunton, College of Engineering, Electrical Engineering Department
Abstract/Summary
This project presents the design, fabrication, and experimental evaluation of a broadband 3x3 Archimedean spiral antenna array tile for 2.8-3.8 GHz. Each element combines a two-arm spiral on Rogers RO4350B, a printed 50 to 150 Ω tapered balun, and a conductive backplane. Klopfenstein and Exponential feed implementations were modeled in Ansys HFSS, generated and tuned with automated scripting, fabricated, and evaluated with calibrated network and anechoic-chamber measurements. The Klopfenstein-fed hardware met the -10 dB input-reflection criterion across the project band. The exponential array provided a broad matched response but reached approximately -8 dB near 2.95 GHz. Measured center-element patterns retained the broadside, forward-directed behavior predicted by simulation, although upper-band agreement was limited by the 1.2 m chamber setup range and phase incoherence. At 3.3 GHz, simulation produced approximately 7.58 dBi boresight RHCP gain and 7.4 dB RHCP-to-LHCP discrimination. The completed work provides a scalable tapered balun fed antenna array for demonstrations and a restored Python-based chamber workflow for future antenna measurements at Cal Poly.
URL: https://digitalcommons.calpoly.edu/eesp/744