Design and Analysis of Annular Ring Microstrip Patch Antenna for Satellite Communication

Microstrip antennas play a significant role in modern communication and radar systems due to their unique advantages. In this paper we have designed and analyzed a dual-band annulur ring microstrip patch antenna tailored for Ku and K-band satellite communication and radar applications. The antenna features an RT Duroid 5880 LZ substrate and incorporates a modified annulus ring structure with a "psi" shaped slot to enhance performance. The antenna operates in two distinct frequency bands: Band-I (16.725–17.357 GHz), centered at 17.02 GHz, with an S11 of -21.34 dB and an impedance bandwidth of 1.03 GHz, and Band-II (21.083–21.972 GHz), centered at 21.475 GHz, with an S11 of -36.66 dB and an impedance bandwidth of 889 MHz. At the respective center frequencies, the antenna achieves gains of 6.69 dB and 7.49 dB, with corresponding directivities of 8.47 dB and 9.64 dB. The radiation efficiencies are 81.3% for Band-I and 78.9% for Band-II. An optimization study of the impedance bandwidth revealed that the optimal feed width is 0.06 cm. The antenna's excellent dual-band performance, high gain, and radiation efficiency make it well-suited for satellite applications, particularly for radio location systems.