| With the development of science and technology in recent years,the communication rate increases and the electromagnetic environment interference becomes more and more complicated,so it is very important to design a receiver system with ultra-wideband,high sensitivity and anti-electromagnetic interference.And antenna and filter are important devices in receiver front-end system,and their performance directly affects the efficiency of the whole system.This thesis is based on the research work I have undertaken during my master's degree,there is a series of studies on the design of the ultra-wide band Vivaldi antenna,Vivaldi array antenna,Vivaldi notched antenna and multi-band filters.The follows:(1)A miniaturized,high-gain ultra-wide band Vivaldi antenna with T slotted loading and dielectric cut-off is presented.By etching T-shaped slot on the main radiation surface,the current path is extended and miniaturization of the antenna is realized..The electric field radiation is extended and the high gain of the antenna is realized.The range of working frequency is 2-30 GHz and the maximum gain is 8 dBi.Finally,the array is designed based on this Vivaldi antenna unit,and a T type power divider is designed to achieve the impedance match,and a 1 × 4 Vivaldi array antenna is designed.Its working frequency range is 0.9-10.8GHz,and its maximum gain is 9.28 dBi.(2)Based on the design of Vivaldi antenna element proposed in Chapter 3,Vivaldi antennas with single notch band and multi-notch bands are designed by loading D-CRLH and Shunt-line resonator,respectively.Then the characteristics of the resonator are analyzed.Finally,the overall characteristics of the Vivaldi antenna with notch are analyzed.(3)Two design of multi-band bandpass filter(BPF)with multiple transmission zeros is proposed,which which consists of a cross-shaped stubstructure and a stepped impedance resonator(SIR).Also,based on the transmission line theory and ABCD matrix,the characteristic of resonance and transmission zero are investigated by using the derived formulas and circuit simulators.Then,the mixed electric and magnetic coupling(MEMC)between resonators and the source/load coupling are applied to produce transmission zeros for enhancing the selectivity and improving the out-of-band suppression of the quad-band BPF.Finally,two compact multi-band filter are designed and fabricated,and their measured frequency response are found agree well with the simulated results. |
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