A printed V-shaped circular antenna array for direction finding applications

The design and implementation of a v-shaped 8-element circular antenna array for vehicular direction finding (DF) applications is proposed. The antenna array is designed to operate at 2.45 GHz with a -10dB bandwidth of about 150 MHz, thus covering the ISM band. The antenna was designed on an FR4 epoxy substrate with 0.8 mm thickness and an outer radius of 100 mm. We present the simulation results for two different excitation modes; phase excited and switched operation. A comparison between the simulated and the measured resonating frequency, -10 dB bandwidth and the |S₁₁| characteristics for all the eight arms of the antenna under the switched mode of operating indicate a high correlation between the measured and simulated values. In addition, investigation of the azimuthal radiation patterns for the two modes prove the superiority of the phased excitation mode in terms of higher directive beams at the expense of increased hardware complexity.