US5949309A — Dielectric resonator filter configured to filter …

Claim 1

Independent Claim 267 words

A signal filter that passes an in-band portion of an amplified radio frequency signal to be transmitted from an antenna and suppresses an out-of-band portion of said amplified radio frequency signal, comprising: a housing having a hollow interior portion; an input terminal connected to said housing and configured to receive said amplified radio frequency signal as an input signal; plural resonant cavities contained within said hollow interior portion of said housing, each comprising conductive walls and a dielectric resonator configured to suppress a narrowband frequency component in said out-of-band portion of said amplified radio frequency signal; a microstrip transmission line disposed within said hollow interior portion of said housing, comprising, a dielectric layer, a conductive trace having a planar external surface, and a conductive layer, said dielectric layer being sandwiched between said conductive trace and said conductive layer, said microstrip transmission line connected on one end to said input terminal and configured to receive said input signal, respective segments of said planar external surface of said conductive trace exposed to an interior portion of respective of said plural resonant cavities so that at least one of said dielectric resonator suppresses said narrowband frequency component and provides a filtered output signal at another end of said microstrip transmission line, and a stub for providing a symmetrical frequency response and group delay in said in-band portion between at least two of said narrowband frequency components filtered by at least two of said resonant cavities; and an output terminal connected to said housing and said another end of said microstrip transmission line and configured to output said filtered output signal.

Claim 2

Dependent Claim 267 words

A signal filter that passes an in-band portion of an amplified radio frequency signal to be transmitted from an antenna and suppresses an out-of-band portion of said amplified radio frequency signal, comprising: a housing having a hollow interior portion; an input terminal connected to said housing and configured to receive said amplified radio frequency signal as an input signal; plural resonant cavities contained within said hollow interior portion of said housing, each comprising conductive walls and a dielectric resonator configured to suppress a narrowband frequency component in said out-of-band portion of said amplified radio frequency signal; a microstrip transmission line disposed within said hollow interior portion of said housing, comprising, a dielectric layer, a conductive trace having a planar external surface, and a conductive layer, said dielectric layer being sandwiched between said conductive trace and said conductive layer, said microstrip transmission line connected on one end to said input terminal and configured to receive said input signal, respective segments of said planar external surface of said conductive trace exposed to an interior portion of respective of said plural resonant cavities so that at least one of said dielectric resonator suppresses said narrowband frequency component and provides a filtered output signal at another end of said microstrip transmission line, and a stub for providing a symmetrical frequency response and group delay in said in-band portion between at least two of said narrowband frequency components filtered by at least two of said resonant cavities; and an output terminal connected to said housing and said another end of said microstrip transmission line and configured to output said filtered output signal.

Claim 3

Dependent Claim 46 words

The filter of claim 1, wherein: said each conductive walls comprises a material having a negative temperature coefficient; and said each dielectric resonator comprises a ceramic material having a positive temperature coefficient that is matched in magnitude to said negative temperature coefficient of said conductive walls.

Claim 4

Dependent Claim 68 words

The filter of claim 2, wherein: said microstrip transmission line comprises a trace layer which comprises said conductive trace, and said microstrip transmission line having a bored portion formed therein; and said each dielectric resonator of said plural resonant cavities comprising a base disposed through said bored portion, said base attached on a first surface to said dielectric resonator and attached on a second surface to said housing.

Claim 5

Dependent Claim 35 words

The filter of claim 1, wherein said microstrip transmission line comprises a printed circuit board on which said conductive layer is formed, said dielectric layer formed over said conductive layer of said printed circuit board.

Claim 6

Dependent Claim 11 words

The filter of claim 4, wherein said dielectric layer comprises polytetrafluoro-ethylene.

Claim 7

Dependent Claim 55 words

The filter of claim 4, wherein a thickness of said dielectric layer is in a range of 1/32 and 1/16 of an inch and supports transmission of signal frequencies in at least one of a first frequency range between 2.15 GHz and 2.162 GHz and a second frequency range between 2.5 GHz, to 2.686 GHz.

Claim 8

Dependent Claim 35 words

The filter of claim 1, wherein said stub is conductively connected to said conductive trace, said stub having an impedance that counterbalances an impedance disturbance on said microstrip transmission line caused by said dielectric resonator.

Claim 9

Dependent Claim 30 words

The filter of claim 7, wherein said stub is disposed at a location on said microstrip transmission line that is across from at least one of said plural resonant cavities.

Claim 10

Dependent Claim 20 words

The filter of claim 7, wherein said stub has a length in the range of 0.05 inches to 0.3 inches.

Claim 11

Dependent Claim 40 words

The filter of claim 1, further comprising a tuning disk adjustably disposed within one of said plural resonant cavities at a variable distance from a dielectric resonator, a center frequency of said narrowband frequency component varying with said variable distance.

Claim 12

Dependent Claim 25 words

The filter of claim 10, wherein said tuning disk comprises at least one of a manually tunable tuning disk and an automatically tunable tuning disk.

Claim 13

Dependent Claim 62 words

The filter of claim 1, wherein at least one of said conductive walls being arranged in a plane that is substantially normal to a plane of said planar external surface of said conductive trace, said at least one of said conductive walls having a notched portion formed therein, said notched portion insulatively disposed over said planar external surface of said conductive trace.

Claim 14

Dependent Claim 175 words

A signal filter that passes an in-band portion of an amplified radio frequency signal to be transmitted from an antenna and suppresses an out-of-band portion of said amplified radio frequency signal, comprising: a housing having a hollow interior portion; an input terminal connected to said housing and configured to receive said amplified radio frequency signal as an input signal; resonant cavity means for suppressing magnitudes of a lower narrowband frequency component and an upper narrowband frequency component in said out-of-band portion of said amplified radio frequency signal; microstrip transmission line means for accepting said input signal from said input terminal, feeding said input signal to said resonant cavity means, and outputting a filtered output signal having said out-of-band portion suppressed in magnitude with respect to said input signal; means for providing a symmetrical frequency response and group delay in said in-band portion between said lower narrow band frequency component and said upper narrowband frequency component; and an output terminal that provides said filtered output signal from said microstrip transmission line means to an external device.

Claim 15

Dependent Claim 175 words

A signal filter that passes an in-band portion of an amplified radio frequency signal to be transmitted from an antenna and suppresses an out-of-band portion of said amplified radio frequency signal, comprising: a housing having a hollow interior portion; an input terminal connected to said housing and configured to receive said amplified radio frequency signal as an input signal; resonant cavity means for suppressing magnitudes of a lower narrowband frequency component and an upper narrowband frequency component in said out-of-band portion of said amplified radio frequency signal; microstrip transmission line means for accepting said input signal from said input terminal, feeding said input signal to said resonant cavity means, and outputting a filtered output signal having said out-of-band portion suppressed in magnitude with respect to said input signal; means for providing a symmetrical frequency response and group delay in said in-band portion between said lower narrow band frequency component and said upper narrowband frequency component; and an output terminal that provides said filtered output signal from said microstrip transmission line means to an external device.

Claim 16

Dependent Claim 23 words

The filter of claim 13, further comprising temperature stabilizing means for automatically compensating for temperature induced frequency changes in said resonant cavity means.

Claim 17

Dependent Claim 38 words

The filter of claim 13, wherein said means for providing a symmetrical frequency response and group delay comprises impedance compensating means for counterbalancing an impedance disturbance on said microstrip transmission line means caused by said resonant cavity means.

Claim 18

Dependent Claim 21 words

The filter of claim 13, wherein said resonant cavity means comprises tuning means for changing a frequency of said frequency component.

Claim 19

Dependent Claim 70 words

The filter of claim 13, wherein: said resonant cavity means establishes a resonance condition in at least one of a first frequency range between 2.15 GHz and 2.162 GHz and a second frequency range between 2.5 GHz, to 2.686 GHz; and said microstrip transmission line means for passing said in-band portion of said radio frequency signal in at least one of said first frequency range and said second frequency range.

Claim 20

Dependent Claim 40 words

The filter of claim 13, further comprising means for preserving a frequency symmetry of the in-band portion of said amplified radio frequency signal and applying a symmetrically shaped group delay to said in-band portion of said amplified radio frequency signal.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2002-09-06	2003-03-08	2003-09-07	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2006-09-06	2007-03-08	2007-09-07	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2010-09-06	2011-03-08	2011-09-07	$7700.00	Window Closed / Lapsed

Dielectric resonator filter configured to filter radio frequency signals in a transmit system

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