Design of Wideband Co-Linearly-Polarized Magnetoelectric Dipole Antenna With Stable Gain for Vehicular Sensing and Communications

A novel wideband co-linearly-polarized magnetoelectric (ME) dipole antenna with stable gain has been designed for vehicular sensing and communications applications, which uses folded ME dipole, decoupling plate, irregular metal wall, slots on the bottom of the suspended rectangular tube, and parasitic metal posts. Firstly, by using folded ME dipole, the operating bandwidth can be broadened significantly. Then, a series of technologies for adjusting the transmission zero are introduced to improve the isolation across the whole bandwidth, by using decoupling plate, irregular metal wall, slots on the bottom of the suspended rectangular tube to change the current distribution. Furthermore, several methods modifying the field distribution are employed to realize the stable and high gain covering the working band, by utilizing the additional metal posts combined with the irregular metal wall, slots on the bottom of the suspended rectangular tube for changing the deteriorated field distribution. Finally, the proposed antenna with the above three significant contributions is fabricated and measured to validate the proposed design. The experiment results show that the wide operational bandwidth across 1.75-3.95 GHz (77.2%), good polarization isolation higher than 22 dB, and the peak gain of 9.1 dBi with a stable fluctuation less than 1.5 dBi are obtained. These superiorities demonstrate a very promising candidate for applications in in-band full-duplex fields, which will greatly facilitate the development of vehicular sensing and communications.