Analysis of broadband pair of slot cut equilateral triangular microstrip antenna

The broadband microstrip antenna is realized by cutting slot of different shapes like, U-slot, V-slot and rectangular slot at an appropriate position inside the patch. The slot is said to introduce a resonant mode near the fundamental mode resonance frequency of the patch and realizes broader bandwidth. In most of the slot cut designs, the slot length is taken to be either quarter wave or half wave in length. In this paper, broadband pair of rectangular slots cut equilateral triangular microstrip antenna is discussed. The analysis to study the effect of rectangular slot on the broadband response of triangular patch is presented. It was observed that the slot does not introduce any mode but modifies the resonance frequency of higher order TM₁₁ mode of the patch and along with the fundamental TM₁₀ mode realizes broader bandwidth. The slot also alters the directions of surface current at higher order mode and gives broadside radiation pattern over the entire bandwidth.