Design And Research On Conformal Dual-band Antenna And Multi-band Filter

With the rapid development of wireless communication system, multi-band antennagradually become a hot research topic. The flexible antenna have received much attention fortheir advantages of convenient integration with other microwave components and easyconforming to the carrier in recent years. On the other hand, as a key research contents in thenew century-frequency selective surface (FSS), and which can be called a spatial filter, thedesign requirements keeps getting higher with the development of wireless communicationtechnology. Miniaturization, stable performance and multi-band are several developmentfeature. As a special filter, the metamaterial (MM) have received more and more attention. Inrecent years, domestic and foreign scholars committed to the research of multiple frequencyand miniaturization of unit, thus design special filter with high performance. In addition, as akey component of the wireless RF front end-filter, its miniaturization, multi-band and highperformance become the research hotspot. This thesis are studied mainly from the followingaspects:Firstly, a flexible fishtail-shaped antenna based on conventional bow-tie antenna and forWiMAX and X-band applications is presented, simulated, analyzed, fabricated, and measured.The new antenna get size greatly reduced and achieved dual-band performance comparedwith the conventional bow-tie antenna. Also, the antenna is fed by CPW feedlines that areeasy to integrate with system circuits. Finally, the proposed antenna under different bendingconditions is tested. Measurements show a very low susceptibility to performance due tobending, which indicates the future viability implementation of flexibility devices.Secondly, a dual-band special filter based on conventional split ring resonator ispresented. Transmission characteristics, the incident angle stability, and current distributionsare discussed. Then the dual-band special filter is fabricated and measured. Measured resultsagree well with simulated ones and prove the effectiveness of the principle. This planarspecial filter adopt a flexible dielectric-slab and is easily to conform to material surface. Ingeneral, the design dual-band special filter promote the development of the dual-band ormulti-band stealth medium and special filter of conformal shape.Finally, a simple tri-mode asymmetry stub-load resonator (ASLR) unit is proposed anddesigned, and the equivalent circuit and features are analyzed. Based on this, two ASLRs arefolded and coupled in preudo-interdigital format to design a triple-band bandpass filter. Theselectivity of passband is improved by using two order resonators, and the feeder on bothsides are coupled to the resonators through aperture couple. The frequency can selected byadjusting the ratios of impedance and electrical length, which improve the selectivity of the triple-band filter. The three passbands of the filter are GPS,4G, and WiMAX applications.The filter is compact and easy integrated with other components. At last, the filter isfabricated and measured, the measurements are in good agreement with simulations, whichtestify the correctness and effectiveness of the analysis and design theory.