Research On Microstrip Filter And Antenna Based On Crlh TL

With the development of wireless communication technology, its application in remote control system has become more and more widespread. So the WiFi technology application in the field of control deserves deeper research, and it can be foreseen that our production and life style will be promoted and changed. In addition, the wireless module of the control terminal is mostly working in two or more frequency bands, and the miniaturization of antenna within the control terminal has also become a key technology in antenna design. On the other hand, wireless signal coverage is expanding, which may bring some electromagnetic interference to high-precision receiving device. Therefore, as widely used microwave devices, performance and miniaturization demands of microstrip band-pass or band-stop filters are getting higher, and there is considerable application prospect in the anti-interference of control system.Because of these, the paper researched and completed the innovative design of a miniaturized microstrip antenna operating at 2.45 GHz and two dual-band microstrip filters:1. Based on the CRLH TLs, a compact 2.45 GHz antenna with electromagnetic bandgap (EBG) double-negative (DNG) meta-materials is designed and manufactured. The two electromagnetic bandgap (EBG) structures modified by adjusting to non-uniform structures are used as the basic radiation part of microstrip antenna. The resonant frequency can be determined by the size of the microstrip patch and the radius of via. Moreover, the patch dimension is only 20.0 mm×19.8 mm.2. Based on hairpin stepped impedance resonators (SIR), a dual band-stop filter operating at 0.9 GHz and 1.8 GHz is designed, fabricated and measured for the isolation of mobile phone interference. The multistage stepped-impedance is loaded on coupling line of the traditional hairpin SIR, and two stop-band are generated. The center stop-band frequeny depends on the dimensions of the external SIR, and both of the two stop-band frequencies and bandwidths can be adjustable by the multistage stepped-impedance.3. A compact dual-band filter is designed and fabricated based on asymmetrical stepped impedance resonators (SIR) for the requirements of base station. The filter is operating at 0.9 GHz and 1.8 GHz, and the two central passband frequencies and bandwidths of the proposed filter can be adjustable by the geometric parameters. The folded stepped impedance resonator modified by adding an inner quasi-lumped SIR stub is used as the basic module of a novel configuration of dual band-pass filter to produce two different passbands. The first passband of the filter only depends on the dimensions of the external SIR, while the second passband depends on both the external SIR and the quasi-lumped stub.