Design of a Novel 0.2 to 40 GHz Ultra-Wideband High-Gain Combined Antenna with and without Dielectric Lens

摘要

In this paper, at first, design and fabrication of an ultra wide-band combined antenna will be presented. By using the idea of combined antennas, a TEM horn antenna is combined with magnetic dipoles in order to achieve a good matching for this antenna. Proposing a suitable transition structure from Coaxial cable to the antenna, the discontinuity confronting the wave is reduced and finally, a bandwidth of 180 MHz to 30 GHz is obtained for this structure. Also, the fabrication results for this antenna verify simulation results. In the next step, another wideband element with smaller dimensions will be designed. The small dimensions of this element help its pattern not to deteriorate and not split into parts at high frequencies. Next, a dielectric lens is utilized in its aperture to increase the gain of this element. This lens increases the gain by 11 dB at high frequencies of the band. A bandwidth of 200 MHz to 40 GHz is achieved for this structure. The plots of return loss, pattern in several frequencies, and antenna's gain in terms of frequency will be presented.