This paper presents development of a new planar spiral feed for a satellite boresight reference antenna, operating at two widely separated frequency bands (2200-2300 MHz and 8000-8400 MHz). A stepped ground plane cavity with different quarter wavelength distances is proposed to provide unidirectional patterns at these frequency bands. A back lobe suppression of around 12 dB in 2 GHz band and better than 15 dB in 8 GHz band with a measured on-axis axial ratio of less than 3 dB is achieved for the dual band planar spiral feed with stepped ground plane cavity configuration. A boresight reflector antenna employing this feed has measured beamwidths of 7 degrees and 1.8 degrees respectively and gain of 26 dBi and 36 dBi at 2250 MHz and 8200 MHz.Index Terms-Boresight reference, cavity backed feed, spiral antenna, stepped ground plane.

No abstract

A printed square slot loop antenna capable of radiating slant 45‐degree polarized signals over a wideband is presented. A radial wideband stub feeds the square slot loop at the diagonal and the antenna exhibits an impedance and radiation bandwidth of more than octaveband (1.7 to 3.5 GHz). © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 470–473, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22164

No abstract

No abstract