Research And Design Of Multi-band Planar Printed Antennas

With the rapid development of personal communication and wireless networks, asthe indispensable component of wireless communication system, the antenna isdeveloping into miniaturization, multi-band and broadband. Microstrip antenna，whichhas the features of small size, low profile, easy to fabricate and able to be integratedwith microwave circuits, can meet the demands of system requirements.The paper gives emphasis to the designs of multi-band WLAN/WiMAX antennas,four novel multi-band planar printed antennas are designed. First the paper gives anoutline of the development situation, the basic theory and analytical approach of themicrostrip antennas. Besides, the technological means of antennas of miniaturization,multi-band and broadband are summarized. At last, four novel multi-band antennas aredescribed in detail, It is Multi-band monopole antenna with CPW-fed working at thebands of DCS/WLAN/WiMAX, Tri-band monopole antenna with microstrip feed lineworking at the bands of WLAN/Bluetooth/WiMAX, Tri-band microstrip antenna withsemiellipse-shaped slot etched on the patch working at the bands ofUMTS/WLAN/WiMAX and Multi-band microstrip antenna with several slots likesemiellipse-shaped, rectangle-shaped and T-shaped etched on the patch working at thebands of DCS/WLAN/WiMAX.Ansoft Corporation’s electromagnetic simulation software HFSS is used foranalyzing the four antennas. The performances of major parameters, feed methods, andprinciple of radiation are discussed. The performance indexes meet requirements inworking band, gain and radiation direction. So they have certain value to the practicalwireless communication applications.