Research And Design Of Airborne Low-frequency Narrow-band Filter

The circuit has certain narrowband frequency selective amplification often been request in the wireless correspondence. We expect the filter of receiver have a narrow bandpass ,when dealing with a narrowband small singal.Designed a kind of active narrowband filter circuiut on the basis of circuit simulation and experiments. According to the actual needs the circuit board be made with some special process. Hardware filter require additional components, and adaptability is not strong. These shortcoming can be overcome with software filterAll kinds of methods design FIR digital was derived based on optimization algorithm.These methods has better performance. Radial basis function neural network algorithm has good convergence and convergence speed. Compared with other optimization algorithm also has certain advantages in stability. Radial basis function neural network algorithm combines the radial basis function (RBF) network and FIR digital filters. Improved RBF algorithm can adjust the weight coefficient .According to the actual need to adjust the weight coefficient.It is very important to the performance of FIR digital filters.The interfere come from 400Hz airborn power and 50Hz power is serious.When the signal very weak frequence interference is fatal. In the small signal processing how to suppress the power frequency interference is very important.The performance of the subsidence filter is decided the performance of communicational navigation system.The FIR digital filters using algorithm medths has good performance in experimental.