Research And Design Of The Planar Filtering Antenna

Antenna and bandpass filter are both key components for wireless communication system, which aim to transmit the signals within the operating frequency range and block the out-of-band noises., Combing antenna and filter, the filtering antenna can be formed. Compared with the traditional antenna design, the circuit size of the filtering antenna can be reduced as the matching section is removed. Meanwhile, the feature of high out-of-band suppression can improve the performance of the wireless communication system.In this thesis, filtering antennas have been studied widely based on the synthesis design method and three prototypes of planar filtering antennas are designed. Such antennas are as follows: a novel filtering antenna using a dual-mode resonator, a dual-band filtering antenna and wideband slot filtering antenna.In Chapter 3, two filtering antennas have been designed based on third-order and fifth-order bandpass filter. The center frequencies are 2.06 GHz and 2.04 GHz, and the fractional bandwidths are 2.33% and 3.24%, respectively. The two filtering antennas both exhibit good performance, and the measured results are in good agreement with the simulated ones.In Chapter 4, a dual-bands filtering antenna has been proposed, whose center frequencies are 2.03 GHz and 2.16 GHz and the fractional bandwidths are1.58% and 0.88%, respectively.In Chapter 5, a wideband filtering slot antennas have presented based on the half-wave resonator and the quarter-wavelength resonator. The center frequencies of both antennas are 4.9GHz, while the fractional bandwidths are 18.96% and 23.36%, respectively. The measured results and simulated results agree well with each other. The results show that both slot filtering antennas can be applied in wideband communication systems.