| 摘要 |
A sharply tuned bandpass RF filter (100) is presented herein. The filter (10 0) has an input port (101) for receiving television RF signals and passing same to an output port (102) for application to a load (106). The filter (100) is tuned such that it exhibits the characteristic of passing only RF signals having frequencies within a given frequency channel out of a plurality of channels, all having the same frequency bandwidth while rejecting all other frequencies. The bandwidth of each channel is on the order of W MHz. The filter (100) exhibits an amplitude response within a mandated mask such that when operated in an RF transmitter the amplitude of the response is attenuat ed uniformly about the center frequency of the given channel within a frequency range of about .plusmn. 0.5W MHz to a maximum of about .plusmn. (0.5W+0.45) MHz and extending to an attenuated level of about -1 to -18 dB from the in- band power level.
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