Patent ID: 6933986
Filing Date: 2005-08-23
Classification: H04N

Abstract:
1. A sharply tuned bandpass RF filter, said filter having an input port for receiving digital television RF signals and passing same to an output port of said filter for application to a load; said filter being 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; said bandwidth of each said channel being on the order of W MHz; said filter exhibiting an amplitude response within a mandated digital television signal mask such that when operated in an RF transmitter the amplitude of the response is attenuated uniformly about the center frequency of said 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.