A Compact Dual-Band Dual-Pattern Mode Antenna Design

A compact dual-band dual-pattern mode antenna is proposed in this article. A microstrip rectangular semi-ring antenna that has the feature of compact size is first employed as the driven element. Then by placing a parasitic element next to the driven element, a novel dual-band dual-pattern mode antenna is designed. In the first band, the beam peak of the proposed antenna steers from the broadside, called the microstrip Yagi mode. In the second band, the beam peak of the proposed antenna changes to the broadside direction, which can be regarded as the broadside mode. A prototype operated at C-band is designed, fabricated, and measured to verify the proposed design methodology.