A broadband circular microstrip antenna with two pairs of slots

A novel broadband circular microstrip antenna with two pairs of slots is proposed in this paper. Due to the two pairs of embedded slots in the circular patch, two resonant modes of similar radiation characteristics are found to be excited. The two closely excited resonant modes can cause the enhancement of the impedance bandwidth of the proposed circular microstrip antenna. The proposed antenna design and obtained broadband performance are presented. The measured bandwidth of 15.2% is achieved with small sizes, and the good radiation characteristic for operating frequencies within the impedance bandwidth is also observed.