Design and Optimization of a High-Gain Filtering Antenna Based on Parasitic Pixel Layer

A novel high-gain filtering antenna based on the parasitic pixel layer is designed and optimized in this letter. Initially, a circular patch surrounded by a shorted concentric annular ring one is proposed as the radiation source, such a design is able to realize an upper radiation null. Afterward, a parasitic pixel layer is placed upon the radiation source with an air gap. Another radiation null at the lower band is then obtained by optimizing the connection status between adjacent pixel elements based on the internal multiport method. Besides that, the parasitic pixel layer can enhance the realized broadside gain. Finally, a high-gain filtering antenna with a bandpass response is obtained. The antenna is validated by a full-wave simulation study followed by the experimental verification. Measured results indicate that the antenna can operate from 4.7 to 5.4 GHz with an average gain of 9.6 dBi and two radiation nulls at the lower and upper band edges of the reflection coefficient curve.