Enhanced broadband operation of an active mixer

Patent metadata

Field	Value
Publication number	US-10193497-B2
Application number	US-201715831370-A
Country	US
Kind code	B2
Filing date	Dec 4, 2017
Priority date	Dec 6, 2016
Publication date	Jan 29, 2019
Grant date	Jan 29, 2019

Abstract

Methods, systems, and devices for wireless communication are described for enhanced broadband operation of an active mixer. In an example, an apparatus may include an active mixer that converts between radio frequency (RF) signals and intermediate frequency (IF) signals based at least in part on an alternating current (AC) local oscillator (LO) signal, wherein a direct current (DC) current generated within the active mixer is dependent in part on a bias voltage and the AC LO signal. The apparatus may include a mixer biasing circuit that generates the bias voltage for the active mixer, a magnitude of the bias voltage having an inverse relationship to an amplitude of the AC LO signal.

First claim

What is claimed is:

1. An apparatus for wireless communication, comprising:
an active mixer configured to convert between radio frequency signals and intermediate frequency signals based at least in part on an alternating current local oscillator signal, wherein a direct current generated within the active mixer is dependent in part on a bias voltage and the alternating current local oscillator signal; and
a mixer biasing circuit configured to generate the bias voltage for the active mixer, a magnitude of the bias voltage depending at least in part on an amplitude of the alternating current local oscillator signal, the mixer biasing circuit comprising a feedback loop configured to inversely control the magnitude of the bias voltage with respect to the amplitude of the alternating current local oscillator signal.

2. The apparatus of claim 1 , further comprising:
a combiner circuit configured to generate a biased local oscillator signal for input to the active mixer, the biased local oscillator signal being a composite of the bias voltage and the alternating current local oscillator signal.

3. The apparatus of claim 2 , wherein the mixer biasing circuit further comprises:
a current source configured to provide a reference electrical current; and
a transconductance circuit configured to receive the reference electrical current and the alternating current local oscillator signal.

4. The apparatus of claim 3 , wherein the mixer biasing circuit further comprises:
a differential amplifier comprising a first input configured to receive a voltage of the transconductance circuit, a second input configured to receive a reference voltage, and an output configured to output the bias voltage.

5. The apparatus of claim 3 , further comprising:
a differential drive circuit that comprises the transeonductance circuit and a second transconductance circuit, the second transconductance circuit configured to receive the reference electrical current, the differential drive circuit configured to respectively receive differential inputs of the alternating current local oscillator signal.

6. The apparatus of claim 2 , wherein the mixer biasing circuit further comprises:
a differential amplifier; and
a p-channel metal-oxide semiconductor field-effect transistor with a drain electrically connected to a current source and the differential amplifier; and
wherein the differential amplifier comprises a first input electrically connected to the drain of the p-channel metal-oxide semiconductor field-effect transistor, a second input configured to receive a reference voltage, and an output configured to output the bias voltage.

7. The apparatus or claim 1 , wherein the active mixer is selected from the group consisting of a single-balanced active mixer, a double-balanced active mixer, or a single-transistor active mixer.

8. The apparatus of claim 1 , wherein the active mixer comprises:
a switch circuit configured to generate the direct current within the active mixer based at least in part on the bias voltage and the alternating current local oscillator signal.

9. The apparatus of claim 1 , wherein the alternating current local oscillator signal has a frequency within a defined frequency range, and the amplitude of the alternating current local oscillator signal varies as a function of frequency over the defined frequency range.

10. The apparatus of claim 1 , wherein the amplitude of the alternating current local oscillator signal varies based at least in part on temperature, process corners at a specific frequency, or both.

11. The apparatus of claim 1 , wherein the active mixer comprises an input configured to receive a signal for upconversion and is configured to upconvert the signal from a first intermediate frequency to a first radio frequency.

12. The apparatus of claim 1 , wherein the active mixer comprises an input to receive a signal for downconversion and is configured to downconvert the signal from a first radio frequency to a first intermediate frequency.

13. An apparatus for wireless communication, comprising:
active mixing means for converting between radio frequency signals and intermediate frequency signals based at least in part on an alternating current local oscillator signal, wherein a direct current generated within the active mixing means is dependent in part on a bias voltage and the alternating current local oscillator signal;
mixer biasing means for generating the bias voltage for the active mixing means, a magnitude of the bias voltage depending at least in part on an amplitude of the alternating current local oscillator signal; and
means for inversely controlling the magnitude of the bias voltage with respect to the amplitude of the alternating current local oscillator signal.

14. The apparatus of claim 13 , further comprising:
combiner means for generating a biased local oscillator signal for input to the active mixing means, the biased local oscillator signal being a composite of the bias voltage and the alternating current local oscillator signal.

15. The apparatus of claim 13 , wherein the active mixer means further comprises:
input means for receiving a signal for upconversion, the active mixer means for upconverting the signal from a first intermediate frequency to a first radio frequency.

16. The apparatus of claim 13 , wherein the active mixer means further comprises:
input means for receiving a signal for downconversion, the active mixer means for downconverting the signal from a first radio frequency to a first intermediate frequency.

17. A method for wireless communication, comprising:
generating a bias voltage with a magnitude that depends at least in part on an amplitude of an alternating current local oscillator signal;
generating a direct current within an active mixer, wherein the generated direct current is dependent on the bias voltage and the alternating current local oscillator signal;
converting, by the active mixer, a signal between a radio frequency and an intermediate frequency based at least in part on the alternating current local oscillator signal; and
inversely controlling the magnitude of the bias voltage with respect to the amplitude of the alternating current local oscillator signal.

18. The method of claim 17 , wherein converting the signal between the radio frequency and the intermediate frequency comprises:
upconverting the signal from the intermediate frequency to the radio frequency.

19. The method of claim 17 , wherein converting the signal between the radio frequency and the intermediate frequency comprises:
downconverting the signal from the radio frequency to the intermediate frequency.

20. An apparatus for wireless communication, comprising:
means for generating a bias voltage with a magnitude that depends at least in part on an amplitude of au alternating current local oscillator signal;
means for generating a direct current within an active mixer, wherein the generated direct current is dependent on the bias voltage and the alternating current local oscillator signal; and
means for converting, by the active mixer, a signal between a radio frequency and an intermediate frequency based at least in part on the alternating current local oscillator signal; and
means for inversely controlling the magnitude of the bias voltage with respect to the amplitude of the alternating current local oscillator sural.

21. The apparatus of claim 18 , wherein converting the signal between the radio frequency and the intermediate frequency compr

Assignees

• Qualcomm Inc

Inventors

• Yu Xinmin
• Gathman Timothy Donald
• Leung Lai Kan

Classifications

• H03D7/1491 Primary

  Arrangements to linearise a transconductance stage of a mixer arrangement · CPC title

• H04B1/26 Primary

  for superheterodyne receivers (multiple frequency-changing H03D7/16) · CPC title

• H03D7/1441

  using field-effect transistors (H03D7/145 takes precedence) · CPC title

• H03D7/1425

  with transistors · CPC title

• H03B2200/0062

  Bias and operating point · CPC title