ARRANGEMENT FOR USING AT LEAST ONE AUXILIARY ANTENNA TO PROVIDE DIFFERENT RADIATION PATTERNS TO ADJACENT-CHANNEL NTSC AND DTV TELEVISION SIGNALS TRANSMITTED FROM A COMMON MAIN ANTENNA.

摘要

First and second (especially NTSC and DTV) component television signals that respectively occupy first and second immediately-adjacent channels are simultaneously transmitted. These first and second component television signals have respective first and second radiation patterns that are different from each other. A main antenna broadcasts a composite signal including the first and second component television signals according to a composite radiation pattern. At least one auxiliary antenna transmits a tapped component signal derived from only one (NTSC or DTV but not both) of the first and second component television signals. The auxiliary antenna defines a component radiation pattern that, when added to the composite radiation pattern defined by the main antenna, results in a combined radiation pattern in which the first component television signal has a radiation pattern that is different from the radiation pattern of the second component television signal. In this manner, the NTSC and DTV signals transmitted from the same location may be steered differently from each other. Further, two separate auxiliary antennas for respective NTSC and DTV component television signals may be provided, to provide enhanced steering.