초록 ▼

A self-aligning resonator filter, a self-aligning coupled resonator filter circuit, and a television tuner circuit incorporating the filter and the circuit are disclosed herein. The self-aligning resonator filter leverages the local oscillator of the tuner circuit and can be realized with a signific

A self-aligning resonator filter, a self-aligning coupled resonator filter circuit, and a television tuner circuit incorporating the filter and the circuit are disclosed herein. The self-aligning resonator filter leverages the local oscillator of the tuner circuit and can be realized with a significant reduction in the amount of off-chip components. The self-aligning resonator filter is configured to align its tunable resonator to resonate at a desired frequency in response to a phase difference measured across a resistance element during a tuning mode, and the resistance element is switched out of the self-aligning resonator filter during a run mode. The self-aligning coupled resonator filter circuit is configured to isolate its individual resonator stages during tuning such that each resonator stage can be aligned without being influenced by the other resonator stage. The television tuner circuit can be manufactured at relatively low cost while retaining high performance and the ability to be dynamically aligned while in use.

대표청구항 ▼

What is claimed is: 1. A self-aligning coupled resonator filter circuit comprising: a first tunable resonator stage having a first filter output node; second tunable resonator stage having a second filter input node coupled to said first filter output node; and a switching architecture configured t

What is claimed is: 1. A self-aligning coupled resonator filter circuit comprising: a first tunable resonator stage having a first filter output node; second tunable resonator stage having a second filter input node coupled to said first filter output node; and a switching architecture configured to isolate said first tunable resonator stage from said second tunable resonator stage for closed loop tuning of said first tunable resonator stage when the self-aligning coupled resonator filter circuit is in a first tuning mode, such that presence of said second tunable resonator stage does not influence tuning of said first tunable resonator stage, and to facilitate closed loop tuning of said second tunable resonator stage when the self-aligning coupled resonator filter circuit is in a second tuning mode, such that presence of said first tunable resonator stage does not influence tuning of said second tunable resonator stage. 2. A self-aligning coupled resonator filter circuit according to claim 1, said switching architecture being configured to connect a coupling capacitance element between said first filter output node and said second filter input node when the self aligning coupled resonator filter circuit is in said run mode. 3. A self-aligning coupled resonator filter circuit according to claim 2, said first tunable resonator stage comprising a first tunable resonator, and said switching architecture being configured to connect said coupling capacitance element in parallel with said first tunable resonator when the self-aligning coupled resonator filter circuit is in said first tuning mode. 4. A self-aligning coupled resonator filter circuit according to claim 2, said second tunable resonator stage comprising a second tunable resonator, and said switching architecture being configured to connect said coupling capacitance element in parallel with said second tunable resonator when the self-aligning coupled resonator filter circuit is in said second tuning mode. 5. A self-aligning coupled resonator filter circuit according to claim 1, further comprising an oscillator having an oscillator output node, said oscillator being configured to generate a tuning signal at said oscillator output node, wherein said first tunable resonator stage includes a first reference input node coupled to said oscillator output node, and said second tunable resonator stage includes a second reference input node coupled to said oscillator output node. 6. A self-aligning coupled resonator filter circuit comprising: a first tunable resonator stage having a first filter output node; a second tunable resonator stage having a second filter input node coupled to said first filter output node; a switching architecture configured to isolate said first tunable resonator stage from said second tunable resonator stage for closed loop tuning of said first tunable resonator stage when the self-aligning coupled resonator filter circuit is in a first tuning mode, and to facilitate tuning of said second tunable resonator stage when the self-aligning coupled resonator filter circuit is in a second tuning mode; and an oscillator having an oscillator output node, said oscillator being configured to generate a tuning signal at said oscillator output node, wherein said first tunable resonator stage includes a first reference input node coupled to said oscillator output node, and said second tunable resonator stage includes a second reference input node coupled to said oscillator output node; wherein said first tunable resonator stage comprises: a first tunable resonator coupled to said first filter output node; a first resistance element connected between said first reference input node and said first filter output node when the self-aligning coupled resonator filter circuit is in said first tuning mode; and a first phase detector loop controller coupled between said first reference input node and said first filter output node, said first phase detector loop controller being configured to measure a first phase difference across said first resistance element, and to adjust said first tunable resonator in response to said first phase difference. 7. A self-aligning coupled resonator filter circuit according to claim 6, further comprising a circuit input node, and said switching architecture comprising: a first switch coupled to said circuit input node, said first resistance element, and said first filter output node, said first switch being controllable to switch between a run state corresponding to a run mode for the self-aligning coupled resonator filter circuit and a first tuning state corresponding to said first tuning mode; said first switch being configured to disconnect said first resistance element from said first filter output node when the self-aligning coupled resonator filter circuit is in said run mode, and to connect said first resistance element to said first filter output node when the self aligning coupled resonator circuit is in said first tuning mode. 8. A self-aligning coupled resonator filter circuit according to claim 6, said second tunable resonator stage comprising: a second tunable resonator coupled to said second filter output node; a second resistance element connected between said second reference input node and said second filter output node when the self-aligning coupled resonator filter circuit is in said second tuning mode; and a second phase detector loop controller coupled between said second reference input node and said second filter output node, said second phase detector loop controller being configured to measure a second phase difference across said second resistance element, and to adjust said second tunable resonator in response to said second phase difference. 9. A self-aligning coupled resonator filter circuit according to claim 8, said switching architecture comprising: a second switch coupled to said second resistance element and said second filter output node, said second switch being controllable to switch between said run state and a second tuning state corresponding to said second tuning mode; said second switch being configured to disconnect said second resistance element from said second filter output node when the self-aligning coupled resonator filter circuit is in said run mode, and to connect said second resistance element to said second filter output node when the self-aligning coupled resonator filter circuit is in said second tuning mode. 10. A method for tuning a self-aligning coupled resonator circuit comprising a first tunable resonator, a second tunable resonator, a coupling capacitor coupled between an output of the first tunable resonator and an input of the second tunable resonator, and a switching architecture coupled between an output of the first tunable resonator and an input of the second tunable resonator, said method comprising: setting the switching architecture to a first tuning state that connects the coupling capacitor in parallel with the first tunable resonator and isolates the first tunable resonator from the second tunable resonator for closed loop tuning of the first tunable resonator when the self-aligning coupled resonator filter circuit is in a first tuning mode, such that presence of said second tunable resonator does not influence tuning of said first tunable resonator; and setting the switching architecture to a second tuning state that connects the coupling capacitor in parallel with the second tunable resonator and isolates the second tunable resonator from the first tunable resonator for closed loop tuning of the second tunable resonator when the self-aligning coupled resonator filter circuit is in a second tuning mode, such that presence of said first tunable resonator does not influence tuning of said second tunable resonator. 11. A method according to claim 10, further comprising setting the switching architecture to a run state that connects the output of the first tunable resonator to the input of the second tunable resonator via the coupling capacitor. 12. A method according to claim 11, wherein: setting the switching architecture to said run state connects an input of the first resonator to a circuit input node of the self-aligning coupled resonator circuit. 13. A method according to claim 10, wherein: setting the switching architecture to said first tuning state disconnects an input of the first tunable resonator from a circuit input node of the self-aligning coupled resonator circuit. 14. A method according to claim 10, wherein tuning of said self-aligning coupled resonator circuit is performed at each power-up cycle of a system that includes said self aligning coupled resonator circuit. 15. A method according to claim 10, wherein tuning of said self-aligning coupled resonator circuit is performed each time a tuner channel is selected for said self-aligning coupled resonator circuit.