Oscillator systems having annular resonant circuitry
Systems and apparatus are provided for solid-state oscillators and related resonant circuitry. An exemplary oscillator system includes an amplifier having an amplifier input and an amplifier output and resonant circuitry coupled between the amplifier output and the amplifier input. In exemplary embodiments, the resonant circuitry includes an annular resonance structure that is substantially symmetrical and includes a pair of arcuate inductive elements. In accordance with one or more embodiments, the resonant circuitry includes an additional inductive element that is capacitively coupled to the annular resonance structure via an air gap to improve the quality factor of the resonant circuitry.
1. An oscillator system comprising:
a first amplifier having a first amplifier input and a first amplifier output; and
an annular resonance structure formed on a substrate, wherein the annular resonance structure includes a first inductive element coupled to the first amplifier output and a second inductive element coupled to the first amplifier input, wherein the first and second inductive elements have substantially identical electrical characteristics, the first and second inductive elements curve towards one another so that the annular resonance structure encompasses a voided interior region, a first longitudinal end of the first inductive element faces a first longitudinal element of the second inductive elements across a first air gap, and a second longitudinal end of the first inductive element faces a second longitudinal element of the second inductive element across a second air gap.
2. The oscillator system of claim 1 , further comprising a third inductive element coupled between the first amplifier and the annular resonance structure, wherein the third inductive element is disposed proximate the annular resonance structure and separated from the annular resonance structure by a third air gap, the third inductive element being coupled to the annular resonance structure via a capacitance provided by the third air gap.
3. The oscillator system of claim 1 , wherein: the first inductive element is a first arcuate inductive element; the second inductive element is a second arcuate inductive element; and wherein the oscillator system includes a first capacitive element coupled between the first longitudinal ends of the first and second arcuate inductive elements; and a second capacitive element coupled between the second longitudinal ends of the first and second arcuate inductive elements.
4. The oscillator system of claim 3 , further comprising a third inductive element coupled between the first amplifier and the first arcuate inductive element, wherein:
the third inductive element is disposed proximate the first arcuate inductive element and separated from the first arcuate inductive element by a third air gap to provide a capacitance between the third inductive element and the first arcuate inductive element; and
the third inductive element is capacitively coupled to the first arcuate inductive element via the capacitance.
5. The oscillator system of claim 3 , wherein the first arcuate inductive element and the second arcuate inductive element are complementary in shape.
6. The oscillator system of claim 3 , wherein the annular resonance structure is symmetrical.
7. The oscillator system of claim 3 , wherein:
the first arcuate inductive element comprises a first substantially C-shaped conductive material; and
the second arcuate inductive element comprises a second substantially C-shaped conductive material.
8. The oscillator system of claim 3 , wherein:
the first arcuate inductive element comprises a first substantially U-shaped conductive material; and
the second arcuate inductive element comprises a second substantially U-shaped conductive material.
9. The oscillator system of claim 1 , wherein the annular resonance structure is symmetrical.
10. The oscillator system of claim 1 , further comprising
a second amplifier having a second amplifier input coupled to the first amplifier input and second amplifier output; and
a power combiner having a first input coupled to the first amplifier output and a second input coupled to the second amplifier output.
11. The oscillator system of claim 10 , wherein the first amplifier is configured to operate in Class AB mode and the second amplifier is configured to operate in Class C mode.
12. The oscillator system of claim 10 , further comprising:
a third amplifier having a third amplifier input and a third amplifier output coupled to a third input of the power combiner; and
a power splitter having a first output coupled to the first amplifier input, a second output coupled to the second amplifier input, and a third output coupled to the third amplifier input.
13. The oscillator system of claim 1 , wherein further comprising: a first capacitive element coupled between the first longitudinal ends of the first and second inductive elements; and a second capacitive elements coupled between the second longitudinal ends of the first and second inductive elements.
14. The oscillator system of claim 13 , further comprising a third inductive element disposed proximate the first inductive element and separated from the first inductive element by a third air gap to provide a capacitance between the third inductive element and the first inductive element, wherein the third inductive element is capacitively coupled to the first inductive element via the capacitance.
15. The oscillator system of claim 14 , further comprising a fourth inductive element disposed proximate the second inductive element and separated from the second inductive element by a fourth air gap to provide a second capacitance between the fourth inductive element and the second inductive element, wherein the fourth inductive element is capacitively coupled to the second inductive element via the second capacitance.
16. The oscillator system of claim 13 , wherein the first inductive element and the second inductive element are complementary in shape and substantially oppose one another.
17. The oscillator system of claim 13 , wherein:
the first capacitive element has a first terminal coupled to the first longitudinal end of the first inductive element and a second terminal coupled to the first longitudinal end of the second inductive element; and
the second capacitive element has a third terminal coupled to the second longitudinal end of the first inductive element and a fourth terminal coupled to the second longitudinal end of the second inductive element.