Abstract:
A microwave filter (78) has a plurality of resonant cavities (1-10) with each cavity containing a dielectric resonator (44). There are self-equalizing probes (80, 82) located between some of the cavities (3 and 8, 2 and 9), and a self-equalizing aperture (84) located between other of the cavities (4 and 7). A circulator (50) is connected to an output (52) of the filter. The circulator has an input/output (86) which is connected to an equalizer (D). The equalizer contains a dielectric resonator (54) that is slightly different from the dielectric resonators (44) of the filter (78) to permit the equalizer to be tuned at a slightly different frequency from the filter. The equalizer (D) and self-equalizing probes (80, 82) and aperture (84) are capable of being operated to reduce a dispersive slope of the filter. The filter operates in a single mode, although dual mode filters are also described. The electrical performance of the filter is superior to prior art filters, particularly in the wideband versions because the dispersive slope is reduced.
Abstract:
This invention relates to a modular contiguous channel multiplexer (46) having one or more modules (41, 42) that produce an asymmetric filter function that is combined with responses from other modules (44) to produce an overall symmetrical response. The multiplexer (46) can have channels (1, 2, 4) arranged in any order of relative frequencies and one or more channels (3, 5) can be added or removed from the multiplexer (46) without disturbing the operation of the existing or remaining channels (1, 2, 4). A method of constructing the multiplexer (46) involves choosing a downstream channel first, then choosing sequentially the channel immediately upstream from the channel last chosen and choosing filters (f, f1) of each channel to meet certain criteria. The filters (f, f1) of each channel are identical to one another but are not necessarily identical to filters (f, f1) in adjacent channels.
Abstract:
This invention relates to a modular contiguous channel multiplexer (46) having one or more modules (41, 42) that produce an asymmetric filter function that is combined with responses from other modules (44) to produce an overall symmetrical response. The multiplexer (46) can have channels (1, 2, 4) arranged in any order of relative frequencies and one or more channels (3, 5) can be added or removed from the multiplexer (46) without disturbing the operation of the existing or remaining channels (1, 2, 4). A method of constructing the multiplexer (46) involves choosing a downstream channel first, then choosing sequentially the channel immediately upstream from the channel last chosen and choosing filters (f, f1) of each channel to meet certain criteria. The filters (f, f1) of each channel are identical to one another but are not necessarily identical to filters (f, f1) in adjacent channels.