Variable duty-cycle multi-standard mixer
View Patent ↗An adjustable mixer is disclosed that is capable of operating in different modes in order to satisfy the mixing requirement of multiple radio access technologies (RATs). The adjustable mixer includes a LO signal generating portion and a mixing portion. Depending on the mixing requirements of the RAT, the adjustable mixer can operate in any one of multiple modes, each mode having a specific configuration for the LO signal generating portion and the mixing portion. The LO signal generating portion generates a LO signal having a particular duty cycle, depending on the selected mode, for use by the mixing portion. The mixing portion has an adjustable circuit configuration that can be dynamically reconfigured based on the selected mode, and which allows the mixing portion to successfully mix received signals using the corresponding LO signals generated by the LO signal generating portion.
1. A mixer, comprising:
a mixer module configured to mix an input signal in accordance with one of a first mixing mode or a second mixing mode;
a duty cycle generator module configured to supply a first local oscillator (LO) signal having a base duty cycle to the mixer module when the mixer module operates in the first mixing mode, or supply a second LO signal having a second duty cycle when the mixer module operates in the second mixing mode, wherein the second duty cycle is different from the base duty cycle; and
a processing module configured to measure a parameter associated with the mixer, and select the first mixing mode or the second mixing mode based on the measured parameter.
2. The mixer of claim 1 , wherein the duty cycle generator module is configured to receive a base LO signal having the base duty cycle, and to generate the first LO signal or the second LO signal from the base LO signal.
3. The mixer of claim 2 , wherein the duty cycle generator module includes a duty cycle conversion module,
wherein the duty cycle generator module is configured to generate the second LO signal by passing the base LO signal through the duty cycle conversion module, and
wherein the duty cycle generator module is configured to generate the first LO signal by causing the base LO signal to bypass the duty cycle conversion module.
4. The mixer of claim 1 , wherein a frequency of the first LO signal is substantially the same as a frequency of the second LO signal.
5. The mixer of claim 1 , wherein the first LO signal has a first period and the second LO signal has a second period,
wherein the first LO signal is active for a first percentage of the first period and the second LO signal is active for a second percentage of the second period, and
wherein the first percentage is greater than the second percentage.
6. The mixer of claim 1 , wherein the mixer module includes:
a first mixer portion having a first terminal and a second terminal;
a second mixer portion having a third terminal and a fourth terminal; and
a switching module configured to connect or disconnect the first terminal with the third terminal and the second terminal with the fourth terminal based on whether the processing module selects the first mixing mode or the second mixing mode.
7. The mixer of claim 1 , wherein the parameter is an IP2 characteristic of an output of the mixer.
8. The mixer of claim 1 , wherein the processor module is further configured to compare the measured parameter to a predetermined threshold, and control the duty cycle generator module to provide the first LO signal or the second LO signal based on the comparison.
9. A mixer, comprising:
a mixer module configured to mix an input signal in accordance with one of a first mixing mode or a second mixing mode, the mixer module including:
an I-mixer configured to mix an in-phase signal portion of an in-phase/quadrature input signal, the I-mixer having a positive input terminal and a negative input terminal,
a Q-mixer configured to mix a quadrature signal portion of the in-phase/quadrature input signal, the Q-mixer having a positive input terminal and a negative input terminal, and
a switching module configured to connect or disconnect the positive input terminal of the I-mixer to the positive input terminal of the Q-mixer, and the negative input terminal of the I-mixer to the negative input terminal of the Q-mixer; and
a duty cycle generator module configured to supply a first local oscillator (LO) signal having a base duty cycle to the mixer module when the mixer module operates in the first mixing mode, or supply a second LO signal having a second duty cycle when the mixer module operates in the second mixing mode, wherein the second duty cycle is different from the base duty cycle.
10. The mixer of claim 9 , wherein the switching module is configured to set the mixer module to operate in the first mixing mode or the second mixing mode.
11. A mixer, comprising:
a mixer module configured to mix an input signal in accordance with one of a first mixing mode or a second mixing mode; and
a duty cycle generator module configured to supply a first local oscillator (LO) signal to the mixer module when the mixer module operates in the first mixing mode, or supply a second LO signal when the mixer module operates in the second mixing mode;
wherein the duty cycle generator module is configured to receive a base LO signal having a base duty cycle, and to generate the first LO signal or the second LO signal from the base LO signal,
wherein the base LO signal includes an in-phase portion and a quadrature portion, and
wherein the duty cycle generator module includes a NAND gate that operates on the in-phase portion and the quadrature portion of the base LO signal in order to generate the second LO signal.
12. A mixer, comprising:
a mixer module configured to mix an input signal with a local oscillator (LO) signal in accordance with one of a first mixing mode or a second mixing mode; and
a duty cycle generator module configured to generate the LO signal to have a first duty cycle during the first mixing mode, or generate the LO signal to have a second duty cycle during the second mixing mode, wherein the second duty cycle is different from the first duty cycle;
wherein the first mixing mode supports wireless communications according to a first radio access technology (RAT), and the second mixing mode supports wireless communications according to a second RAT.
13. The mixer of claim 12 , wherein a frequency of the LO signal is unchanged for both the first duty cycle and the second duty cycle.
14. The mixer of claim 12 , wherein a period of the LO signal is unchanged for both the first duty cycle and the second duty cycle.
15. The mixer of claim 12 , wherein the LO signal has a period,
wherein the LO signal is active for a first percentage of the period for the first duty cycle, and for a second percentage of the period for the second duty cycle, and
wherein the first percentage is greater than the second percentage.
16. A mixer, comprising:
a first mixer portion configured to mix a first portion of an input signal, the first mixer portion including a first input terminal and a second input terminal;
a second mixer portion configured to mix a second portion of an input signal, the second mixer portion including a first input terminal and a second input terminal;
a switching module configured to switch between a first mixing mode and a second mixing mode,
wherein, in the first mixing mode, the first input terminal of the first mixer portion is connected with the first input terminal of the second mixer portion, and the second input terminal of the first mixer portion is connected with the second input terminal of the second mixer portion, and
wherein, in the second mixing mode, the first input terminal of the first mixer portion is disconnected with the first input terminal of the second mixer portion, and the second input terminal of the first mixer portion is disconnected with the second input terminal of the second mixer portion.
17. The mixer of claim 16 , further comprising a duty cycle generator module configured to supply a first local oscillator (LO) signal to the mixer module during the first mixing mode, and configured to supply a second LO signal during the second mixing mode.
18. The mixer of claim 16 , further comprising a processor module configured to analyze a parameter associated with the mixer, and to control the switching module based on the analysis.
19. The mixer of claim 18 , wherein the analysis includes measuring the parameter and comparing the parameter to a predetermined threshold.
20. The mixer of claim 19 , wherein the parameter is an IP2 characteristic of an output signal output from the mixer.