| 摘要 |
PURPOSE:To analyze frequency with the accuracy corresponding to pulse width by arranging plural filter groups consisting of plural filters with the same band width and different bands in parallel to constitute the final filter circuit. CONSTITUTION:An input signal is divided into several RF bands by plural band filters and the output of each band filter is converted into the common RF signal with the same band and multipled by a multiplexer. The common RF signal is inputted to all the narrow band filters 9a-11d included in the 1st, 2nd, and 3rd filter groups 9, 10, 11. Each output from these filters is inputted to a discriminator 8 through a detector 7 and the central frequency of the input signal is discriminated. A signal is outputted from filters 11a-11d in the 3rd filter group 11 with a wide band in case of the input of a pulse with short pulse width and from the filters 9a-9d in the 1st filter group 9 with a narrow band in case of the input of a pulse with long pulse width, thereby analyzing frequency highly accurately. |
