Research And Design Of Frequency Reconfigurable Microstrip Antenna

Based on the frequency microstrip reconfigurable antenna research and design is the maincontent of this paper, with the rapid development of modern communications, in order to achieve the purpose of better communication, navigation and guidance, the transmit and receive antenna need to work at the same platform. In this way, many antennas on the same platform will generate increasing load and electromagnetic compatibility problems. How can use an antenna to achieve the integrated function of multiple antennas is became the hotspot of modern communication. Reconfigurable antenna can use an antenna to achieve a variety of antenna function, it is changed by PIN diodes or MEMS switches, though the opening and closing of the switches can change the radiation patch or ground structure, and thus change the operating frequency of the antenna real-time, the polarization direction and the radiation and so on.First, this article designs a frequency reconfigurable antenna with a feature of band-notch. The antenna adopts micro-strip feeder, with structure of two slotted1-grooves on the ground, instead of slot in radiation patch. When switch is mounted on slotted I-groove, antenna has four operative modes with switch open and closed. Simulations and measurement results show that the antenna’s effective band covers3.5GHz,5.5GHz WiMAX and5.8G WLAN.Second, this article designs a printing micro-strip frequency reconfigurable antenna with the size of50times35square millimeters. The antenna is constructed with three reverse L-shape patches, and the middle one is constituted of micro-strip and patch. Two short pins are set on the bottom of external radiation patch and on the top of middle radiation patch respectively. Switch is mounted on the slot of the ground, reducing its influences on directional diagram. Antenna obtains two operative modes with switch open and closed. Simulations and tests show with switch open, work bandwidth is between1.70GHz and1.95GHz, when the switch close the bandwidth is between3.7GHz-4.5GHz. Finally, this article make some improvements on the second type antenna. By abandoning the inside reverse L-shape patch, the size of antenna is reduced as45times35square millimeters. Then we present comparative results in advanced antenna with previous antenna, and simulation diagram with measurement results.