Coaxial cavity waveguide antennas excited by stacked circular microstrip patches for use as prime‐focus reflector feeds. Issue 4 (28th December 2016)

• Record Type: Journal Article
• Authors: Pour, Zahra A.; Latif, Saeed I.; Qudrat‐E‐Maula, Mohammad; Shafai, Lotfollah
• Is Part Of: International journal of RF and microwave computer-aided engineering. Volume 27:Issue 4(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2016-12-28
• Subjects: coaxial cavity -- microstrip patch -- primary feeds -- reflector antennas -- waveguide; Microwave devices -- Computer-aided design -- Periodicals; Computer-aided engineering -- Periodicals; 621.3813
• DOI: 10.1002/mmce.21076
• Languages: English
• ISSNs: 1096-4290

Abstract

Abstract: A coaxial cavity antenna excited by a stacked circular microstrip antenna is investigated as a feed for prime‐focus parabolic reflector antennas. The radiation pattern of the proposed cavity‐backed antenna is saddle shaped, which widens the −10 dB beamwidths and increases the reflector efficiency especially for deep reflectors with small focal length‐to‐diameter ratios. With a single‐probe feed, the co‐polar radiation pattern is slightly asymmetric in the E‐plane, but is made symmetric by a differential feeding technique, using two probes. The impedance bandwidth of the proposed feed antenna is 20%. The antenna was fabricated and tested, and it exhibited good agreement between simulation and measurement results. The gain factor of the feed was also studied with a circular‐symmetric reflector and provided a gain factor of 79% at f/D = 0.375. This type of feed can be used as an alternative to conventional horn or waveguide feeds, where reduced size and light‐weight are desirable with added advantage of easy integration with electronics.