Based On Rf Direct Sampling Reasearch And Implementation On Reconfigurable Filter

With the rapid development of communication technology, electromagnetic environment is becoming sophisticated, it becomes the focus of current research to develop tunable filter which can cover the whole frequency band and has reconfigurability. In order to effectively combat radio interference, The development of reconfigurable filter not only needs to satisfy the basic function of tunable, but also need to be improved the receiver’s SNR, and has strong anti-interference capability and electromagnetic compatibility. Quality of RF direct sampling receiver performance depends mainly on its front end tunable narrowband bandpass filter. And the receiver size, cost, speed has the very big relations with tunable RF filter. Considering of above, This thesis focuses on the research of the capacitive coupling resonant varactor bandpass filter and a Reconfigurable Microstrip pectinate filter.This thesis based on the principle of capacitive coupled resonator bandpass filter designed a RF LC filter working on 80MHz-90 MHz. By using the ADS2009 software simulation can know the filter has good filtering effect, and can be used for radio frequency band.The focus of this thesis is to design a bandpass filter in a large range of reconfigurable tuning. So according to the project scope of work of the receiver, we designed a combline filter based on single chip microcomputer. The design of the filter can be divided into two parts: One part of the project is to design a microwave bandpass comb line filter; The second part is a single-chip digital circuit which control voltage. The working range is from 600 MHz to 1500 MHz.