Design of a Dual Band Feed Antenna with Large Frequency Ratio

In this paper, a dual band feed antenna with large frequency ratio is presented. In the high-frequency band, the antenna is fed by the inner circular waveguide and employs a linear-shaped dielectric rod for radiation. In the low-frequency band, the coaxial waveguide loaded with an orthomode transducer (OMT) constitutes the feeding network, and an axially corrugated horn is employed for radiation. According to simulation results, reflection coefficients of the antenna are lower than -10dB from 8.6 to 9.1GHz and lower than -15dB from 71 to 86GHz, respectively. The radiation patterns are almost rotationally symmetrical at the main lobe area in the two frequency bands.