Broadband Magnetoelectric Dipole Antenna with High Suppression in Second Harmonic Frequency

This manuscript presents a 45° single-polarized magnetoelectric (ME) dipole antenna with a broad band and high suppression in second harmonic frequency, moreover, no extra filtering circuit is required. The ME dipole is composed of several shorted pins and four rectangular patches, and it is excited by a slot. By adopting a H-shaped slot and bat-shaped stripline, it can realize a broad band and stable gain in the passband. In order to obtain a high suppression in second harmonic frequency, a shorted strip, a stub and a split resonant loop are adopted inside the dipole to introduce two radiation nulls to enhance the suppression in second harmonic frequency. It has weak interference on pass-band and doesn't increase the size of ME dipole. As a result, the antenna exhibits a broad band working in C-band and X-band from 6 to 10.8GHz, and the average gain is 5.5dBi. The harmonic suppression level can be up to 17dB from 17 to 21GHz and the efficiency is suppressed to less than 7%. These results reveal that the proposed antenna without extra filtering circuit can not only work in a wide band, but also have a high harmonic suppression.