Compact Microstrip Antenna Arrays with Low SLL and High Directivity

This paper presents two low side-lobe level (SLL) antenna arrays. Different from conventional low SLL array designs, the elements in the proposed arrays have equal spacing and are excited with uniform amplitude and phase. Adopting triangular or rectangular microstrip antenna as the element, the proposed arrays are numerically investigated. Less than -20 dB SLL and high directivity are obtained simultaneously. The merits of the proposed arrays are their high radiation efficiency, compact structure and ease of complicated feeding network.