A sharply tuned bandpass RF filter is presented herein. The filter has an input
port for receiving television RF signals and passing same to an output port for
application to a load. The filter 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 exhibits an amplitude response within a mandated mask such that when
operated in an RF transmitter the amplitude of the response is attenuated uniformly
about the center frequency of the given channel within a frequency range of about
0.5W MHz to a maximum of about (0.5W+0.45) MHz and extending to an
attenuated level of about -;1 to -;18 dB from the in-band power level.