An X-Band Dual Circular Polarized Single Feed Three-Element Microstrip Patch Array Antenna

The proposed study investigates dual circular polarization in the X-band (8-12 GHz) frequency range. Using a single input microstrip line feed approach, the design employs three microstrip patches (patch #1, #2, and #3) as an array. The design also incorporates both-sided MIC (microwave integrated circuit) technology, which simplifies the entire procedure. On Advanced Design System (ADS) software, the task is created and simulated with Teflon as a substrate material. The input signal from the input port is eventually routed to three patches using the U-shaped slot with flared arm ends in the ground plane. The meander line in the design is crucial for achieving circular polarization by allowing the phase difference between signals feeding to patches. Without the meander line, the antenna would only emit linear polarization. Left-hand circular polarization is achievable by meandering lines between Patch #1 and #3. Meander lines between the other patches (#1 and #2) gives polarization of other senses (right-hand circular polarization). At 10.05 GHz, the antenna has an axial ratio of 0.26 dB and an axial ratio bandwidth of 140 MHz. The antenna has a maximum gain of 9.5 dBi which is comparatively higher than other array antenna containing more than three elements in the design. The antenna has an impedance bandwidth of 6% for -10 dB return loss. The return loss less than -40 dB indicates that the antenna is properly matched in the resonant frequency.