A Single-Feed, High-Gain, Circularly Polarized S-Band Antenna and Its Test Coupler
Abstract
unicationsCircular polarizationThe development of a single-feed, high-gain, circularly polarized 'cup-dipole' antenna, operated over the frequency band of 2.24-2.25 GHz, and its test coupler is described. The antenna consists of a turnstile feed of crossed dipoles of unequal lengths, backed by a cup cavity. With a cup size of 1.33 wavelength in diameter, it produces a gain of 12.7 dB when matched to a VSWR of 1.1. This corresponds to an effective receiving area 6% larger than the physical area. An even higher gain of 13.4 DB, or an aperture efficiency of 122.5%, is observed when the antenna is flush- mounted on a large plate. The radiation pattern shows that the antenna has a half-power breamwidth of approximately 40 degrees and an axial ratio of < or = 0.5 dB over the angular region of plus or minus 10 degrees off boresight.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 05, 1973
- Accession Number
- AD0769907
Entities
People
- Kuo-chun Lang
Organizations
- Massachusetts Institute of Technology