Composite right/left handed (CRLH) branch-line couplers
First Claim
1. A branch-line coupler apparatus for generating separate signal channels from a radio-frequency (RF) connection, comprising:
- a plurality of radio-frequency (RF) connections configured for receiving an input signal;
a plurality of branch lines interconnecting said plurality of RF connections;
wherein each said branch line comprises a transmission line (TL) segment;
wherein at least a portion of said branch lines comprises a composite right/left handed (CRLH) TL; and
wherein capacitance and inductance contributions of a left-handed (LH) TL section and a right-handed (RH) TL section of said CRLH TL are chosen so that a phase response of said CRLH TL is dominated by a LH contribution at below a center frequency, while the phase response is dominated by a RH contribution at above the center frequency.
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Accused Products
Abstract
High-frequency couplers and coupling techniques are described utilizing artificial composite right/left-handed transmission line (CRLH-TL). Three specific forms of couplers are described; (1) a coupled-line backward coupler is described with arbitrary tight/loose coupling and broad bandwidth; (2) a compact enhanced-bandwidth hybrid ring coupler is described with increased bandwidth and decreased size; and (3) a dual-band branch-line coupler that is not limited to a harmonic relation between the bands. These variations are preferably implemented in a microstrip fabrication process and may use lumped-element components. The couplers and coupling techniques are directed at increasing the utility while decreasing the size of high-frequency couplers, and are suitable for use with separate coupler or couplers integrated within integrated devices.
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Citations
16 Claims
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1. A branch-line coupler apparatus for generating separate signal channels from a radio-frequency (RF) connection, comprising:
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a plurality of radio-frequency (RF) connections configured for receiving an input signal; a plurality of branch lines interconnecting said plurality of RF connections; wherein each said branch line comprises a transmission line (TL) segment; wherein at least a portion of said branch lines comprises a composite right/left handed (CRLH) TL; and wherein capacitance and inductance contributions of a left-handed (LH) TL section and a right-handed (RH) TL section of said CRLH TL are chosen so that a phase response of said CRLH TL is dominated by a LH contribution at below a center frequency, while the phase response is dominated by a RH contribution at above the center frequency. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A branch-line coupler apparatus for generating separate signal channels from a radio-frequency (RF) connection, comprising:
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a plurality of radio-frequency (RF) connections configured for receiving an input signal; a plurality of branch lines interconnecting said plurality of RF connections; wherein each said branch line comprises a transmission line (TL) segment; wherein at least a portion of said branch lines comprises a composite right/left handed (CRLH) TL. - View Dependent Claims (12, 13, 14, 15)
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16. A branch-line coupler apparatus for generating separate signal channels from a radio-frequency (RF) connection, comprising:
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a plurality of radio-frequency (RF) connections configured for receiving an input signal; a plurality of branch lines interconnecting said plurality of RF connections; wherein each said branch line comprises a transmission line (TL) segment; wherein at least a portion of said branch lines comprise one or more unit cells; wherein at least one said unit cell comprises a series combination of a right-handed inductor and a left-handed capacitor; and wherein said series combination of said right-handed inductor and said left-handed capacitor is coupled to a paralleled combination of a right-handed shunt capacitor and a left-handed shunt inductor.
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Specification