Wideband microstrip magnetoelectric dipole antenna with stripline aperture-coupled excitation

A novel wideband microstrip magnetoelectric (ME) dipole antenna excited by a stripline aperture-coupled feeding structure is proposed and demonstrated. An antenna prototype is fabricated with low-cost standard printed circuit board process on three substrates and tested. Measured results show that an impedance bandwidth for voltage standing wave ratio (VSWR) <2 is approximate to 42% (10.2-15.6GHz), and a measured boresight gain is approximate to 7.8 +/- 0.7dBi. Almost stable and symmetrical unidirectional radiation patterns with low in cross-polarization and backward radiation are obtained over the entire operating frequency band. By employing the proposed radiating element, two types of cavity (one is a square cavity, the other is a circular cavity) are introduced for enhancing the antenna gain and investigated. After analysis, a better one is chosen to be fabricated and measured. A measured impedance bandwidth for VSWR < 2 is approximate to 45% (10.1-15.9GHz), and a measured boresight gain is approximate to 8.9 +/- 0.5dBi. The measured average gain is approximate to 1.1 dBi larger than that of the radiating element. The measured radiation patterns, cross-polarization levels and half power beam width are almost the same as that of the radiating element except that the measured front-to-back ratios are improved several decibels.