The Design Of The Digitally Tunable Frequency-Hopping Filter With Variable Coupling

With the rapid development of modern wireless communication technology,and peopleincreasingly diversified demand for communication,the microwave filter design with theadvantages of low cost,high performance,small size and ease to design gets the more andmore favour of people. One of the main means of anti-interference in military communicationis the use of frequency hopping technology in wireless communication, and if the system isused in proper center frequency can quickly change of the frequency hopping bandpassfilter,which can improve anti-jamming performance of the system significantly Because ofthis frequency hopping communication as one of the main methods of modern militarycommunication, become the hot spot of research at home and abroad today.The frequency hopping filter is an important part of a frequency hopping radio,the range ofearly frequency hopping radio is relatively narrow, mostly in30~80MHz,in order to increasethe anti-jamming performance, the frequency range of high-end extended to110MHz. But theproblem is that in the whole frequency range bandwidth difference is too big, in-band flatnessseriously bad and the VSWR is too high at the low-end and high-end,which can’t satisfy therequirement of the communication technology and seriously restrict the development of fhcommunication.In this paper, the main work is to research and design a LC frequency hopping filter at30MHz~110MHz. The thesis summarizes the background and significance of frequencyhopping filter and the research status and main function of the frequency hopping filter.On thebasis, put forward the improvement scheme of the inductive coupling numerical controlfrequency hopping filter and gives the corresponding parameter measuring principle andmethod. based on the theory of filter network, introduced the design of low-pass prototypefilter, then derived the coupled resonator bandpass filter. According to improve theperformance of the frequency hopping filter at the low-end and high-end.Then use the ADSsimulation software to optimize the simulation and finally achieve the required design index.Finally complete the debugging and testing of filter material, analyzes the weakness offilter and puts forward the content to research on the follow-up work of the subject.