Resonator circuit and amplifier circuit

• US 8,698,570 B2
• Filed: 06/07/2011
• Issued: 04/15/2014
• Est. Priority Date: 06/07/2010
• Status: Active Grant

• Current Assignee: Cornell University
• Original Assignee: Cornell University
• Inventors: Afshari, Ehsan, Lee, Wooram
• Primary Examiner(s): KINKEAD, ARNOLD M
• Application Number:
  US13/702,444
• Publication Number:
  US 20130207725A1
• Time in Patent Office: 1,043 Days
• Field of Search: 333/219, 333/218, 331/177.V, 331/51, 331/107.SL, 331/96, 331/107.DP, 331/36.C, 331/167, 330/286
• US Class Current: 331/167
• CPC Class Codes: H03B 19/00 Generation of oscillations by non-regenerative frequency multiplication or division of a signal from a separate source transference of modulation from one carrier to another H03D7/00
• CPC Class Codes: H03F 7/04 using variable-capacitance element; using variable-permittivity element
• CPC Class Codes: H03G 3/00 Gain control in amplifiers or frequency changers

Abstract

A passive frequency divider in a CMOS process. More specifically, an electrical distributed parametric oscillator to realize a passive CMOS frequency divider with low phase noise. Instead of using active devices, which are the main sources of noise and power consumption, an oscillation at half of the input frequency is sustained by the parametric process based on nonlinear interaction with the input signal. For example, one embodiment is a 20 GHz frequency divider utilizing a CMOS varactor and made in a 0.13 μm CMOS process. In this embodiment: (i) without any dc power consumption, 600 mV differential output amplitude can be achieved for an input amplitude of 600 mV; and (ii) the input frequency ranged from 18.5 GHz to 23.5 GHz with varactor tuning. In this embodiment, the output phase noise is almost 6 dB lower than that of the input signal for all offset frequencies up to 1 MHz. Also, a resonant parametric amplifier with a low noise figure (NF) by exploiting the noise squeezing effect. Noise squeezing occurs through the phase-sensitive amplification process and suppresses one of two quadrature components in input noise. When the input signal is only in the direction of the non-suppressed quadrature component, squeezing can lower that NF by almost 3 dB. The resonant structure of the proposed amplifier achieves the squeezing effect using a low number of LC elements.

Claims

1. A resonator circuit comprising:

a pump module;

a first transmission line;

a second transmission line; and

a set of capacitor sub-module(s);

wherein;

the first transmission line has a first end and a second end and a plurality of inductive elements located between the first end and the second end;

the second transmission line has a first end and a second end and a plurality of inductive elements located between the first end and the second end;

the first end of the first transmission line is directly electrically connected to the first end of the second transmission line at a first transmission line connection node;

the pump module is structured, located, programmed and/or connected to pump alternating current electrical energy at a wavelength of λ

_p to the first and second transmission lines at the first transmission line connection node;

each capacitor sub-module of the set of capacitor sub-module(s);

(i) includes at least one variable capacitor, and (ii) is electrically connected between the first transmission line and the second transmission line; and

the first transmission line, the second transmission line and the set of capacitor sub-modules are structured and/or connected to produce a signal differential standing wave having a wavelength of λ

_s, which is an integral multiple of λ

_p.

2. The circuit of claim 1 wherein the resonator can operate over a range of λ

_p values between a minimum λ

_p value and a maximum λ

_p value, with the minimum λ

_p value corresponding to a frequency of at least 5 gigahertz.

3. The circuit of claim 1 wherein the first transmission line, the second transmission line and the set of capacitor sub-module(s) are implemented in a CMOS process.

4. The circuit of claim 1 wherein the resonator circuit is incorporated into one of the following types of larger circuits:

a frequency divider, a phase locked loop, or an amplifier.

5. The circuit of claim 1 wherein each capacitor sub-module of the set of capacitor sub-module(s) comprises two variable capacitors connected to each in series at a common node.

6. The circuit of claim 5 wherein each capacitor sub-module of the set of capacitor sub-module(s) further comprises a fixed capacitor electrically connected to the common node.

7. The circuit of claim 6 wherein each fixed capacitor of each capacitor sub-module of the set of capacitor sub-module(s) is electrically connected between the common node and an electrical ground.

8. A resonator circuit comprising:

a pump module; and

a plurality of capacitor-inductor modules;

wherein;

each capacitor-inductor module of the plurality of capacitor-inductor modules comprises a first inductive element, a second inductive element and a capacitor sub-module;

the first inductive elements of the plurality of capacitor-inductor modules are electrically connected in series to form a first transmission line;

the second inductive elements of the plurality of capacitor-inductor modules are electrically connected in series to form a first transmission line;

a first end of the first transmission line is directly electrically connected to a first end of the second transmission line at a first transmission line connection node;

the pump module is structured, located, programmed and/or connected to pump alternating current electrical energy at a wavelength of λ

_p to the first and second transmission lines at the first transmission line connection node;

each capacitor sub-module of the plurality of capacitor-inductor modules comprises two variable capacitors and a fixed capacitor, with the variable capacitors being connected to each other, in series at a common node, between the first and second inductive elements and with the fixed capacitor being electrically connected between the common node and an electrical ground; and

the variable capacitors, the fixed capacitors and the inductive elements are structured to produce a signal differential standing wave having a wavelength of λ

_s , which is an integral multiple of λ

_p.

9. The circuit of claim 8 wherein the resonator can operate over a range of λ

_p values between a minimum λ

_p value and a maximum λ

_p value, with the minimum λ

_p value corresponding to a frequency of at least 5 gigahertz.

10. The circuit of claim 8 wherein the variable capacitors of the capacitor sub-modules are CMOS varactors.

11. The circuit of claim 8 wherein the resonator circuit is incorporated into one of the following types of larger circuits:

a frequency divider, a phase locked loop, or an amplifier.

12. The circuit of claim 8 further comprising an additional capacitor sub-module electrically connected between a second end of the first transmission line and a second end of the second transmission line, wherein the additional capacitor sub-module comprises two variable capacitors and a fixed capacitor, with the variable capacitors being connected to each other, in series at a common node, between the second end of the first transmission line and the second end of the second transmission line and with the fixed capacitor being electrically connected between the common node and an electrical ground.

13. The circuit of claim 12 wherein the second end of the first transmission line and the second end of the second transmission line are directly electrically connected to each other.

14. An amplifier circuit comprising:

an input module;

an output module;

a pump module; and

a resonator portion;

wherein;

the resonator portion comprises a first transmission line and a second transmission line;

the input module is electrically connected to the first transmission line and the second transmission line and is structured and/or connected to input an input signal to the first and second transmission lines;

the first end of the first transmission line is directly electrically connected to the first end of the second transmission line at a first transmission line connection node;

the pump module is structured, located, programmed and/or connected to pump alternating current electrical energy at a wavelength of λ

_p to the first and second transmission lines at the first transmission line connection node;

the resonator portion is structured and/or connected to produce a pump standing wave with a wavelength of λ

_p and a signal differential standing wave having a wavelength of λ

_s , which is an integral multiple of λ

_p;

the output module is electrically connected to the first transmission line and the second transmission line at a location where there is a zero crossing point in the pump standing wave signal; and

the output module is structured and/or connected to receive an output signal from the first and second transmission lines, with the output signal exhibiting noise squeezing.

15. The circuit of claim 14 wherein:

λ

_s is two times λ

_p;

the signal differential standing wave is one half of λ

_s in length;

the pump standing wave is λ

_p in length; and

the output module is connected to the first and second transmission lines at a (¾

)λ

_p position.

16. The circuit of claim 14 wherein the resonator portion and the output module are structured and/or connected so that the amplifier circuit is characterized by a negative noise figure.