Granted Patent B2

US 7,609,779 · App. 11/363,463 · Granted Oct 27, 2009

Abstract

Claims (32)

1. An integrated circuit configured to perform IQ modulation by interleaving in-phase and quadrature signals, the integrated circuit comprising:

a baseband in-phase stage that receives an in-phase analog input signal;

a baseband quadrature stage that receives a quadrature analog input signal; and

a switching mixer having a first plurality of switches and a second plurality of switches, and the switching mixer receiving in-phase and quadrature signals from the baseband in-phase stage and the baseband quadrature stage, wherein

each switch of the first plurality of switches is configured to apply a different one of a first, a second, a third, and a fourth phase of a plurality of phases a carrier period to a different one of a direct in-phase signal, an inverted in-phase signal, a direct quadrature signal, and an inverted quadrature signal derived from the in-phase and quadrature signals, and wherein the switching mixer is configured to combine resulting first up-converted signals to produce a first, interleaved differential signal component, and wherein

each switch of the second plurality of switches is configured to apply the different one of the first, the second, the third, and the fourth phase to another different one of the direct in-phase signal, the inverted in-phase signal, the direct quadrature signal, and the inverted quadrature signal, and wherein the switching mixer is configured to combine resulting second up-converted signals to produce a second differential signal component, wherein

the first differential signal component and the second differential signal component are produced as a differential output signal from the switching mixer, and wherein the differential output signal communicates a first direct and a first inverted in-phase signal during the first phase, a first direct and a first inverted quadrature signal during the second phase, a second direct and a second inverted in-phase signal during the third phase, and a second direct and a second inverted quadrature signal during the fourth phase.

2. The circuit of claim 1 , further comprising an attenuator that controls power to the integrated circuit.

3. The circuit of claim 1 , wherein the switches are transmission gates.

4. The circuit of claim 1 , wherein the switching mixer receives a clocking signal that is directly generated from a voltage-controlled oscillator.

5. The circuit of claim 1 , wherein the in-phase and quadrature phase signals are set to an amplitude signal for modulation in a polar coordinate system, and phase information is imparted through modulation of a clocking signal.

6. The circuit of claim 1 , wherein the first, second, third, and fourth phases include plurality of phases is four phases operating every ¼ carrier period.

7. A method of frequency up-convening I- and Q- signals in IQ modulation, the method comprising:

a switching mixer receiving a baseband in-phase analog signal, wherein the switching mixer includes a first plurality of switches and a second plurality of switches;

the switching mixer receiving a baseband quadrature analog signal;

the switching mixer deriving a direct in-phase signal, an inverted in-phase signal, a direct quadrature signal, and an inverted quadrature signal from the baseband in-phase analog signal and the baseband in-phase quadrature signal;

the first plurality of switches producing first up-convened signals, by each switch of the first plurality of switches applying a different one of a first, a second, a third, and a fourth phase of a plurality of phases a carrier period to a different one of the direct in-phase signal, the inverted in-phase signal, the direct quadrature signal, and the inverted quadrature signal;

the switching mixer interleaving the first up-converted signals to form a first combined signal, wherein the interleaving is done over the first, the second, the third, and the fourth phase;

the second plurality of switches producing second up-converted signals, by each switch of the second plurality of switches applying a different one of the first, the second, the third, and the fourth phase to another different one of the direct in-phase signal, the inverted in-phase signal, the direct quadrature signal, and the inverted quadrature signal;

the switching mixer interleaving the second up-converted signals to form a second combined signal, wherein the interleaving is done over the first, the second, the third, and the fourth phase; and

the switching mixer producing a differential signal that includes the first combined signal and the second combined signal.

8. The method of claim 7 , where interleaving the baseband in-phase analog signal and the baseband quadrature analog signal is at a rate of four times a carrier frequency.

9. A modulator that combines in-phase and quadrature phase analog signals, the modulator comprising:

a clocking mechanism that provides signals corresponding to a first, a second, a third, and a fourth phase of a plurality of phases of a carrier frequency; and

a first plurality of switches that receive a direct in-phase analog signal, an inverted in-phase analog signal, a direct quadrature phase analog signal, and an inverted quadrature phase analog signal, wherein each switch of the first plurality of switches is configured to apply a different one of the first, the second, the third, and the fourth phase to a different one of the direct in-phase signal, the inverted in-phase signal, the direct quadrature signal, and the inverted quadrature signal, and wherein the modulator is configured to combine resulting first up-converted signals to produce a first, interleaved differential signal component;

a second plurality of switches that receive the direct in-phase signal, the inverted in-phase signal, the direct quadrature signal, and the inverted quadrature signal, wherein each switch of the second plurality of switches is configured to apply the different one of the first, the second, the third, and the fourth phase to another different one of the direct in-phase signal, the inverted in-phase signal, the direct quadrature signal, and the inverted quadrature signal, and wherein the modulator is configured to combine resulting second up-converted signals to produce a second differential signal component,

wherein the modulator is configured to produce the first differential signal component and the second differential signal component as a differential output signal, and wherein the differential output signal communicates a first direct and a first inverted in-phase signal during the first phase, a first direct and a first inverted quadrature signal during the second phase, a second direct and a second inverted in-phase signal during the third phase, and a second direct and a second inverted quadrature signal during the fourth phase.

10. The modulator of claim 9 , further comprising amplifiers that up-convert the in-phase and quadrature phase analog signals.

11. The modulator of claim 9 , wherein the plurality of switches are n-channel gates.

12. The modulator of claim 9 , wherein the plurality of switches operate in a range of 1.0 to 2.0 GHz.

13. The modulator of claim 9 , wherein the in-phase and quadrature phase analog signals correspond to cellular phone signals.

14. The modulator of claim 9 , wherein the plurality of switches interleave the in-phase and quadrature phase signals by communicating in-phase and quadrature phase signals during alternating phases over the carrier period.

Assignments (9)