Design of a High-Efficiency Circularly Polarized Antenna Array for Microwave Power Transmission Applications

This paper introduces an enhanced single antenna (SA) design utilizing microstrip technology. The SA’s patch is designed in a square shape which is capable of operating with circular polarization (CP) at 2.45 GHz. To enhance the CP performance, two techniques are incorporated: the slot technique and the slit technique, which also improve the overall performance of the SA. Building upon this SA design, a three-element antenna array is developed, followed by the design and analysis of a six-element antenna array using three software tools (CST MWS, HFSS, and ADS) to validate its effectiveness. The primary objective of the six-element array is to achieve superior gain, directivity, and radiation efficiency compared to both the SA and the three-element array designs. This six-element antenna array is well-matched with the port excitation in terms of the reflection coefficient of -32.65 dB, and the input impedance of 47.15 Ω at 2.45 GHz. In addition, this array has good performance in terms of high gain of 9.09 dBi, high directivity of 9.19 dB, and high radiation efficiency of 97.16% at 2.45 GHz. Also, this array operates in a CP manner with an axial ratio of 1.61 dB. A comparative study is given to demonstrate the benefits of the proposed antenna array with those of existing designs. The proposed antenna array is considered an efficient and eco-friendly solution for feeding small electronic devices across multiple applications.