Research And Design Of Miniaturized Triple-band Antenna

With the rapid development and wide popularization of the information age,the requirements of the electronic and communication system to the antenna are also increasing,the design of miniaturized multi-band antenna has become the focus of research in this field.Based on the traditional microstrip monopole antenna,this paper studies and designs the miniaturized triple-band antennas for different working frequency bands of WLAN and WiMAX.It mainly includes the following work content:(1)Two miniaturized triple-band antennas based on multi-branch structure are designed.The first antenna adopts the radiation structure of two C-shaped branches and one rectangular branch.Three branches correspond to three frequency bands,and the folded branches realize miniaturization design.The other antenna adopts the radiation structure of two annular branches to realize the three-frequency characteristic and miniaturization,and imperfectly add a semicircular patch to optimize impedance matching and bandwidth.The test results show that the three working bands of the two antennas can cover the 2.4GHz,5.8GHz of WLAN and 3.5GHz of WiMAX respectively;the gain of the three center frequencies of the double-ring branch antenna is greater than 0.5dBi,and the cross-polarization level is less than-5.77dB.Both antennas are miniaturized and have good performance.(2)A miniaturized triple-band antenna based on the slot structure of the ground plate is designed.The upper layer of the dielectric plate of the antenna only has a microstrip feeder,and an airplane-shaped slot is opened on the connection floor to realize the triple-band operation.The test results show that the three working frequency bands of the antenna can cover 2.4GHz of WLAN and 3.5GHz,5.5GHz of WiMAX;the gain of the three center frequencies is greater than 2dBi,and the cross-polarization level is less than-7.52dB.The antenna is miniaturized and has good dual polarization and omni-directional radiation characteristics.(3)A triple-band antenna based on the parasitic patch coupling structure is designed.The antenna realizes three-frequency resonance through the parasitic coupling between multiple radiation patches,and a circular slot is made on the connection floor to adjust impedance matching.The measured results show that the three working frequency bands of the antenna can cover 2.4GHz,5.2GHz of WLAN and 3.5GHz of WiMAX;the gain of the three center frequencies is greater than 1.5dBi,and the cross-polarization level is less than-6.92dB.The design method of the triple-band antenna is extended by the combination of the parasitic patch method and the slotting method.