Narrow-band, bandstop filter
AssigneeOrion Industries, Inc.
InventorDouglas R. Jachowski
Life of this patent
Estimating the term…
Abstract
A multi-resonant notch filter incorporates a stepped impedance transmission line with impedance values going from a relatively low value and increasing upward to a relatively high value then back down to a relatively low value again. A plurality of resonant cavitites is coupled to the relatively high central impedance line section of the filter. Other resonators can be coupled to lower impedance sections of the transmission line.
Claims22
A filter comprising:
- a plurality of substantially identical tunable, dielectric resonators;
- a transmission line with an input end and an output end, said line having a first selected impedance value with at least some members of said plurality of resonates coupled thereto and selectively spaced from one another, and from said ends, on said transmission line;
- and
- first and second impedance transformers with said first transformer coupled to said input end and with said second transformer coupled to said output end, each said transformer having an impedance value less than said first impedance value.
A filter comprising:
- a plurality of substantially identical resonators;
- a transmission line with an input end and an output end, said line having a first selected impedance value with at least some members of said plurality of resonators coupled thereto and selectively spaced from one another, and from said ends, on said transmission line;
- first and second impedance transformers with said first transformer coupled to said input end and with said second transformer coupled to said output end, each said transformer having an impedance value less than said first impedance value;
- and
- including second and third transmission line segments each having an impedance value less than said transformer impedance value with each said segment coupled to one of said impedance transformers.
A filter comprising:
- a plurality of substantially identical resonators;
- a transmission line with an input end and an output end, said line having a first selected impedance value with at least some members of said plurality of resonators coupled thereto and selectively spaced from one another, and from said ends, on said transmission line;
- first and second impedance transformers with said first transformer coupled to said input end and with said second transformer coupled to said output end, each said transformer having a impedance value less than said first impedance value;
- and
- with said transmission line folded into a predetermined shape.
A filter useable over a selected frequency band with a center frequency having an associated wavelength comprising:
- a plurality of substantially identical resonators;
- a transmission line with an input end and an output end, said line having a first selected impedance value with at lest some members of said plurality of resonators coupled thereto and selectively spaced from one another, and from said ends, on said transmission line;
- first and second impedance transformers with said first transformer coupled to said input end and wit said second transformer coupled to said output end, each said transformer having an impedance value less than said first impedance value wherein said resonators coupled to said transmission line are spaced from one another an odd number of quarter wavelengths;
- and
- having first and second resonators spaced from one another, on said transmission line on the order of three, quarter wavelengths.
A notch filter with two substantially identical sections comprising:
- a first section with a first transmission line segment having first and second transmission line ends and a first impedance;
- at least one tunable dielectric resonator electrically coupled to said line spaced from said second end;
- a quarter wavelength transformer section with an impedance value lower than said first impedance coupled to said first end and spaced from said resonator;
- and
- a second section, identical to said first section with said second transmission line ends electrically coupled together with each said dielectric resonator tuned to a different frequency.
A notch filter with two substantially identical sections comprising:
- a first section with a first transmission line segment having first and second transmission line ends and a first impedance;
- at least one tunable resonator electrically coupled to said line spaced from said second end;
- a quarter wavelength transformer section with an impedance value lower than said first impedance coupled to said first end and spaced from said resonator;
- a second section, identical to said first section with said second transmission line ends electrically coupled together with each said resonator tuned to a different frequency;
- and
- with each said section including a second transmission line section coupled to said transformer section, said second transmission line section having an impedance less than said transformer section impedance.
A notch filter with two substantially identical sections comprising:
- a first section with a first transmission line segment having first and second transmission line ends and a first impedance;
- at least one tunable resonator electrically coupled to said line spaced from said second end;
- a quarter wavelength transformer section with an impedance value lower than said first impedance coupled to said first end and spaced from said resonator;
- a second section, identical to said first section with said second transmission line ends electrically coupled together with each said resonator tuned to a different frequency;
- and
- with said first transmission line segment formed with a substantial bend therein.
A notch filter comprising:
- a stepped impedance common communication line having an input region, an output region and a center coupling region, each said region having a predetermined impedance value with said input and said output regions each having substantially equal impedance values less than said center coupled in region impedance values;
- and
- a plurality of substantially identical tunable dielectric resonators with at least some of said resonators coupled to said center region, spaced from said input and said output regions, with others of said resonators coupled to said input and said output regions, spaced from said center region, and at least some of said resonators tuned to different frequencies than others.
A filter as in claim 29 usable at a selected frequency with an associated wavelength and having first and second resonators coupled respectively to said input and output regions spaced from said center region a distance on the order of an odd number of quarter wavelengths.
Dependencies are inferred from the claim text.