Resonator circuit
The invention relates to a resonator circuit, the resonator circuit comprising a transformer comprising a primary winding and a secondary winding, wherein the primary winding is inductively coupled with the secondary winding, a primary capacitor being connected to the primary winding, the primary capacitor and the primary winding forming a primary circuit, and a secondary capacitor being connected to the secondary winding, the secondary capacitor and the secondary winding forming a secondary circuit, wherein the resonator circuit has a common mode resonance frequency at an excitation of the primary circuit in a common mode, wherein the resonator circuit has a differential mode resonance frequency at an excitation of the primary circuit in a differential mode, and wherein the common mode resonance frequency is different from the differential mode resonance frequency.
1. A resonator circuit, comprising:
a transformer comprising a primary winding and a secondary winding, wherein the primary winding is inductively coupled with the secondary winding, and wherein a ratio of turns of the primary winding to turns of the secondary winding is 1:2;
a primary capacitor connected to the primary winding, the primary capacitor and the primary winding forming a primary circuit; and
a secondary capacitor connected to the secondary winding, the secondary capacitor and the secondary winding forming a secondary circuit;
wherein the resonator circuit has a common mode resonance frequency at an excitation of the primary circuit in a common mode, wherein the resonator circuit has a differential mode resonance frequency at an excitation of the primary circuit in a differential mode, wherein the common mode resonance frequency is different from the differential mode resonance frequency, and wherein an inductive coupling factor of the transformer in the differential mode is stronger than an inductive coupling factor of the transformer in the common mode.
2. The resonator circuit of claim 1 , wherein the common mode resonance frequency is twice the differential mode resonance frequency.
3. The resonator circuit of claim 1 , wherein the resonator circuit has a further differential mode resonance frequency at an excitation of the primary circuit in the differential mode, wherein the further differential mode resonance frequency is different from the differential mode resonance frequency and the common mode resonance frequency.
4. The resonator circuit of claim 3 , wherein the further differential mode resonance frequency is three times the differential mode resonance frequency.
5. The resonator circuit of claim 1 , wherein the primary winding of the transformer comprises one turn, and wherein the secondary winding of the transformer comprises two turns.
6. The resonator circuit of claim 1 , wherein the primary winding of the transformer or the secondary winding of the transformer is planar.
7. The resonator circuit of claim 1 , wherein the primary winding of the transformer and the secondary winding of the transformer are arranged on the same plane.
8. The resonator circuit of claim 1 , wherein the primary winding of the transformer or the secondary winding of the transformer is connected to a constant voltage source or a ground potential.
9. The resonator circuit of claim 1 , wherein the primary capacitor of the primary circuit comprises a pair of single-ended capacitors.
10. The resonator circuit of claim 1 , wherein the secondary capacitor of the secondary circuit comprises a pair of differential capacitors.
11. The resonator circuit of claim 1 , wherein the primary capacitor or the secondary capacitor comprises a variable capacitor.
12. The resonator circuit of claim 1 , wherein the primary capacitor is connected in parallel to the primary winding.
13. A radio frequency oscillator, comprising:
a resonator circuit, comprising:
a transformer comprising a primary winding and a secondary winding, wherein the primary winding is inductively coupled with the secondary winding, and wherein a ratio of turns of the primary winding to turns of the secondary winding is 1:2;
a primary capacitor connected to the primary winding, the primary capacitor and the primary winding forming a primary circuit; and
a secondary capacitor connected to the secondary winding, the secondary capacitor and the secondary winding forming a secondary circuit;
wherein the resonator circuit has a common mode resonance frequency at an excitation of the primary circuit in a common mode, wherein the resonator circuit has a differential mode resonance frequency at an excitation of the primary circuit in a differential mode, and wherein the common mode resonance frequency is different from the differential mode resonance frequency;
wherein an inductive coupling factor of the transformer in the differential mode is stronger than an inductive coupling factor of the transformer in the common mode; and
an excitation circuit configured to excite the primary circuit of the resonator circuit in the differential mode.
14. The radio frequency oscillator of claim 13 , wherein the excitation circuit comprises at least one transistor for exciting the primary circuit of the resonator circuit.
15. The radio frequency oscillator of claim 13 , wherein the radio frequency oscillator is a class F oscillator.
16. The radio frequency oscillator of claim 14 , wherein the at least one transistor comprises at least one field-effect transistor.
17. The resonator circuit of claim 11 , wherein the variable capacitor is a digitally-tunable capacitor.
18. The resonator circuit of claim 1 , wherein the secondary capacitor is connected in parallel to the secondary winding.