Design Of A Miniaturized Triple-Frequency Microstrip Antenna

A new miniaturized triple-frequency microstrip antenna is proposed. The proposed antenna mainly consists of two circular rings, a circle, a horizontal rectangular strip, three vertical rectangular strips and a defected ground plane. The proposed antenna can generate three separate impedance bandwidths to cover all the 2.4/5.2/5.8GHz Bluetooth/WLAN (Wireless Local Area Network)/RFID (Radio Frequency Identification Devices) operating bands and the 2.5/ 3.5/5.5GHz WiMAX (Worldwide Interoperability for Microwave Access) operating bands. By adding a vertical rectangular strip and a circle along the microstrip direction, the antenna excites two resonant modes and is with miniaturized structure. Because of the introduction of the cambered ground plane with a circular defect, the third wide band with better impedance matching is obtained. Result shows the proposed antenna has good performance.