A Wide Bandwidth 4×4 Circularly Polarized Microstrip Array Antenna for Communication Sensor

The development of a communication antenna employing a sequential phased feeding network and a 4×4 array antenna operating in the X-band is detailed in this article. The proposed antenna implemented a coaxial probe feeding method in its feeding network, which aimed to enhance the gain and axial ratio bandwidth. Each patch is circular-shaped, with a triangular negative perturbation and an elliptical ring slot at the center of the patch radiator. The bandwidth of the reflection coefficient and axial ratio goals must be up to 0.4 GHz. The paper also discusses the comparison between the microstrip feeding networks and the coaxial probe feeding networks. In comparison, coaxial probe feeding can produce better gain, which was up to 12 dBic at the center frequency (8.2 GHz), while microstrip feeding produced nothing but 9.7 dBic at the center frequency (8.2 GHz). The NPC-H220A, with a thickness of 1.6 mm, a dielectric constant of 2.17, and a loss tangent of 0.005, printed the antenna design with a total dimension of 123.7×123.7 mm. The antenna design achieves the required performance and achieves a radiation efficiency of >95%. The angular width is about 22.8°, and the side-lobe level is -21.4 dB. The proposed antenna is suitable for wide-band communication applications.