An Investigation into the Equivalnce of Radiation Characteristics of 90° Circular Sector Microstrip Antenna vis-à-vis Circular Microstrip Antenna

In this work, authors have investigated feed-probe influence on radiation characteristics of 90° circular sector microstrip antenna (CSMA). It is observed that by exciting a 90° CSMA with a feed-probe at two different feed-probe positions, two different modes TM₀₁ and TM21 can be excited within the antenna structure. The resonant frequencies of these two modes are different but both of these modes have broadside radiation patterns in E and H plane. It is also observed that a 90° CSMA resonating at higher order TM₀₁ mode has nearly equivalent radiation characteristics with a circular microstrip antenna resonating at dominant TM₁₁ mode resonating at nearly same frequency. Therefore, the 90° CSMA becomes a suitable alternative to a circular microstrip antenna.