Inductor-capacitor oscillator with embedded second harmonic filter and associated dual core oscillator

Patent metadata

Field	Value
Publication number	US-11152891-B1
Application number	US-202017114410-A
Country	US
Kind code	B1
Filing date	Dec 7, 2020
Priority date	Apr 8, 2020
Publication date	Oct 19, 2021
Grant date	Oct 19, 2021

Abstract

An inductor-capacitor (LC) oscillator with an embedded second harmonic filter and an associated dual core oscillator are provided. The LC oscillator includes a first transistor, a second transistor, a first part-one inductor, a second part-one inductor, a part-one capacitor, a part-two inductor and at least one part-two capacitor. A first end of the first part-one inductor and a first end of the second part-one inductor are coupled to gate terminals of the second transistor and the first transistor, respectively. The part-one capacitor is coupled between the first end of the first part-one inductor and the first end of the second part-one inductor. The part-two inductor is coupled between a second end of the first part-one inductor and a second end of the second part-one inductor. The at least one part-two capacitor is coupled to drain terminals of the first transistor and the second transistor.

First claim

What is claimed is:

1. An inductor-capacitor (LC) oscillator with an embedded second harmonic filter, comprising:
a first transistor and a second transistor;
a first part-one inductor and a second part-one inductor, wherein a first end of the first part-one inductor and a first end of the second part-one inductor are coupled to gate terminals of the second transistor and the first transistor, respectively;
a part-one capacitor, coupled between the first end of the first part-one inductor and the first end of the second part-one inductor;
a part-two inductor, coupled between a second end of the first part-one inductor and a second end of the second part-one inductor; and
at least one part-two capacitor, coupled to drain terminals of the first transistor and the second transistor;
wherein at least the part-two inductor and the at least one part-two capacitor constitute a second harmonic filter to block or weaken second harmonic signals.

2. The LC oscillator of claim 1 , wherein at least the first part-one inductor, the second part-one inductor, the part-two inductor and the part-one capacitor constitute a fundamental frequency resonant tank.

3. An inductor-capacitor (LC) oscillator with an embedded second harmonic filter, comprising:
a first transistor and a second transistor;
a first part-one inductor and a second part-one inductor, wherein a first end of the first part-one inductor and a first end of the second part-one inductor are coupled to gate terminals of the second transistor and the first transistor, respectively;
a part-one capacitor, coupled between the first end of the first part-one inductor and the first end of the second part-one inductor;
a part-two inductor, coupled between a second end of the first part-one inductor and a second end of the second part-one inductor; and
at least one part-two capacitor, coupled to drain terminals of the first transistor and the second transistor;
wherein the first part-one inductor, the second part-one inductor and the part-two inductor are implemented by a continuous metal layer without segmentation.

4. An inductor-capacitor (LC) oscillator with an embedded second harmonic filter, comprising:
a first transistor and a second transistor;
a first part-one inductor and a second part-one inductor, wherein a first end of the first part-one inductor and a first end of the second part-one inductor are coupled to gate terminals of the second transistor and the first transistor, respectively;
a part-one capacitor, coupled between the first end of the first part-one inductor and the first end of the second part-one inductor;
a part-two inductor, coupled between a second end of the first part-one inductor and a second end of the second part-one inductor;
at least one part-two capacitor, coupled to drain terminals of the first transistor and the second transistor; and
a first part-three inductor and a second part-three inductor, wherein the first part-three inductor is coupled between the second end of the first part-one inductor and the drain terminal of the first transistor, and the second part-three inductor is coupled between the second end of the second part-one inductor and the drain terminal of the second transistor.

5. The LC oscillator of claim 4 , wherein at least the part-two inductor, the at least one part-two capacitor, the first part-three inductor and the second part-three inductor constitute a second harmonic filter to block or weaken second harmonic signals of the LC oscillator.

6. The LC oscillator of claim 4 , wherein the first part-one inductor, the second part-one inductor, the part-two inductor, the first part-three inductor and the second part-three inductor are implemented by a continuous metal layer without segmentation.

7. An inductor-capacitor (LC) oscillator with an embedded second harmonic filter, comprising:
a first transistor and a second transistor;
a first part-one inductor and a second part-one inductor, wherein a first end of the first part-one inductor and a first end of the second part-one inductor are coupled to gate terminals of the second transistor and the first transistor, respectively;
a part-one capacitor, coupled between the first end of the first part-one inductor and the first end of the second part-one inductor;
a part-two inductor, coupled between a second end of the first part-one inductor and a second end of the second part-one inductor; and
at least one part-two capacitor, coupled to drain terminals of the first transistor and the second transistor;
wherein the first transistor is a P-type transistor, the second transistor is an N-type transistor, and a first end and a second end of the at least one part-two capacitor are coupled to the drain terminals of the first transistor and the second transistor, respectively.

8. The LC oscillator of claim 1 , wherein both of the first transistor and the second transistor are P-type transistors, or both of the first transistor and the second transistor are N-type transistors.

9. The LC oscillator of claim 1 , further comprising a tail filter coupled to source terminals of the first transistor and the second transistor.

10. The LC oscillator of claim 1 , further comprising a tail filter coupled to a center tap of the part-two inductor.

11. A dual core oscillator, comprising:
a first inductor-capacitor (LC) oscillator and a second LC oscillator identical to each other, wherein each of the first LC oscillator and the second LC oscillator comprises:
a first transistor and a second transistor;
a first part-one inductor and a second part-one inductor, wherein a first end of the first part-one inductor and a first end of the second part-one inductor are coupled to gate terminals of the second transistor and the first transistor, respectively;
a part-one capacitor, coupled between the first end of the first part-one inductor and the first end of the second part-one inductor;
a part-two inductor, coupled between a second end of the first part-one inductor and a second end of the second part-one inductor; and
at least one part-two capacitor, coupled to drain terminals of the first transistor and the second transistor;

wherein the part-two inductor of the first LC oscillator is coupled to the part-two inductor of the second LC oscillator.

12. The dual core oscillator of claim 11 , wherein at least the first part-one inductor, the second part-one inductor, the part-two inductor and the part-one capacitor constitute a fundamental frequency resonant tank.

13. The dual core oscillator of claim 11 , wherein at least the part-two inductor and the at least one part-two capacitor constitute a second harmonic filter to block or weaken second harmonic signals.

14. The dual core oscillator of claim 11 , wherein the first part-one inductor, the second part-one inductor and the part-two inductor within the first LC oscillator and the first part-one inductor, the second part-one inductor and the part-two inductor within the second LC oscillator are implemented by a continuous metal layer without segmentation.

15. The dual core oscillator of claim 11 , wherein each of the first LC oscillator and the second LC oscillator further comprises:
a first part-three inductor and a second part-three inductor, wherein the first part-three inductor is coupled between the second end of the first part-one inductor and the drain terminal of the first transistor, and the second part-three inductor is coupled between the second end of the second part-one inductor and the drain terminal of the second transistor.

16. The dual core oscillator of claim 15 , wherein at least the p

Assignees

• Mediatek Inc

Inventors

• Huang Hao-Wei
• Lin Ang-Sheng
• Chiu Wei-Hao

Classifications

• H03B5/04 Primary

  Modifications of generator to compensate for variations in physical values, e.g. power supply, load, temperature · CPC title

• H03B2200/007

  Generation of oscillations based on harmonic frequencies, e.g. overtone oscillators · CPC title

• H03B2200/0076

  Power combination of several oscillators oscillating at the same frequency · CPC title

• H03B5/1228 Primary

  the amplifier comprising one or more field effect transistors · CPC title

• H03B5/1212 Primary

  the amplifier comprising a pair of transistors, wherein an output terminal of each being connected to an input terminal of the other, e.g. a cross coupled pair · CPC title