Dielectric resonator filter configured to filter radio frequency signals in a transmit system
First Claim
1. 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, anda 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.
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Accused Products
Abstract
A dielectric resonator filter is configured to suppress emissions in an out-of-band frequency portion of an amplified radio frequency (RF) signal prior to transmission of the RF signal by an antenna assembly. The filter includes plural tunable resonant cavities, each of which have a dielectric resonator and are arranged to suppress a magnitude of a frequency component in the out-of-band frequency portion of the RF signal. The amplified RF signal is applied to the plural resonant cavities with a microstrip transmission line. The dielectric resonators are arranged so as to automatically compensate for temperature-induced resonance condition variations.
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Citations
18 Claims
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1. 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:
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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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. 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:
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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. - View Dependent Claims (14, 15, 16, 17, 18)
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Specification