Research On Front-end RF Channel

This paper gives a new method to solve some problems in current radar scout system, that is the front-end RF channel.The system has the adaptive ability for the magnitude and frequency of input signal, and it contain the adaptive RF channel and the digital control. This paper gives the design project of this system, and analyzes each several part of this system. The emphasis of this paper is the frequency-splitting filter with multiple channels and the frequencies-selected filter, work of 3 aspects is chiefly carried out as follows:1. Base on the basic theory of filter, get the approximate equivalent model of pectinate filter and synthesis method of coupled microstrip lines by referring to a great deal data and deducing the formula. Meantime simplify some tedious formulas in the design progress according to actual circumstance. The main calculation and the adjustment can be simulated by software,which suit to the engineers.2. The concrete design and achievement of the frequency-splitting filter. At first, calculate the initial dimension of filter by the software Matlab. the usage with principle of Band- splitting filte ,the corresponding algorithm was get and a frequency-splitting filter with six channels was designed with related software results. Then simulate and optimize the tunable filter by using the simulative software Ansoft Designer. The superiority lies in reduce the insertion loss to a great extent. The more channels the frequency-splitting filter divided, the more obvious the effect is.3. On the basis of pectinate filter,get a combline tunable filter namely the frequency-splitting filter . Then do a research on the frequencies-selected characteristics,which focus on the length of the coupled microstrip lines and the ractor diode.