Adaptive-biased mixer
View Patent ↗A system or method for a circuit network that receives an RF signal, and where a plurality of switching transistors receive an RF signal output by the circuit network and perform mixing with a local oscillation (LO) signal received on a LO input. An active bias circuit performs active bias of the plurality of switching transistors in a feedback loop provided between the LO input and an output of the plurality of switching transistors.
1. An adaptive biased mixer, comprising:
a circuit network that receives an RF differential signal pair and that outputs a differential signal pair;
a plurality of switching transistors that receive the differential signal pair output by the circuit network and that perform mixing with a differential local oscillation (LO) signal pair received on a LO input; and
an active bias circuit that performs active bias of the plurality of switching transistors in a feedback loop provided between the LO input and a differential output of the plurality of switching transistors;
wherein the plurality of switching transistors are biased, without supply of bias from a DC bias current source, to a same voltage via the active bias circuit; and
wherein the active bias circuit defines bias signals of the plurality of switching transistors via the feedback loop, which adaptively controls a LO bias voltage of each switching transistor.
2. The adaptive biased mixer according to claim 1 , further comprising:
a load network that is coupled to the differential output of the plurality of switching transistors, and that provides a load for the differential output of the plurality of switching transistors.
3. The adaptive biased mixer according to claim 2 , further comprising:
a DC offset cancellation circuit provided between the plurality of switching transistors and the active bias circuit.
4. The adaptive biased mixer according to claim 1 , further comprising:
a DC offset cancellation circuit provided between the plurality of switching transistors and the active bias circuit.
5. The adaptive biased mixer according to claim 1 , wherein at least one of the plurality of switching transistors is an N-type metal oxide semiconductor (NMOS) transistor.
6. The adaptive biased mixer according to claim 1 , wherein at least one of the plurality of switching transistors is a P-type metal oxide semiconductor (PMOS) transistor.
7. The adaptive biased mixer according to claim 1 wherein at least one of the plurality of switching transistors is a bipolar junction transistor (BJT).
8. The adaptive biased mixer according to claim 1 , wherein at least one of the plurality of switching transistors is a field effect transistor (FET).
9. adaptive biased mixer according to claim 1 , wherein the active bias circuit comprises an operational amplifier.
10. The adaptive biased mixer according to claim 1 , further comprising:
a low noise amplifier (LNA) that is folded with the mixer.
11. An adaptive biased mixer, comprising:
an input circuit that receives an RF signal;
switching circuitry that switches the RF signal with a local oscillation (LO) signal received on an LO input, to perform a mixing of the RF signal with the LO signal to provide a mixed signal; and
active bias circuitry that performs active biasing of the switching circuitry in a feedback loop provided between the LO input and an output of the switching circuitry;
wherein transistors in the switching circuitry are biased, without supply of bias from a DC bias current source, to a same voltage via the active bias circuit; and
wherein the active bias circuitry defines bias signals of the transistors via the feedback loop, which adaptively controls a LO bias voltage of each switching transistor.
12. The adaptive biased mixer according to claim 11 , wherein the received RF signal is a differential RF signal pair, and wherein the switching circuitry performs mixing with a differential local oscillation signal pair received on the LO input.
13. The adaptive biased mixer according to claim 12 , further comprising:
load circuitry that provides a load for the differential output of the switching means.
14. The adaptive biased mixer according to claim 11 , further comprising:
a DC offset cancellation that cancels a DC offset in signals output by the adaptive biased mixer.
15. The adaptive biased-mixer according to claim 11 , wherein the switching circuitry includes at least one metal oxide semiconductor (MOS) switching transistor.
16. The adaptive biased-mixer according to claim 11 , wherein the switching circuitry includes at least one bipolar junction (BJT) switching transistor.
17. The adaptive biased-mixer according to claim 11 , wherein the switching circuitry includes at least one field effect (FET) switching transistor.
18. The adaptive biased-mixer according to claim 11 , wherein the active bias circuitry includes an operational amplifier.
19. A method of providing a highly-linear output for a mixer, comprising:
receiving an RF signal output by a low noise amplifier;
switching the RF signal with a local oscillation (LO) signal received on an LO input, to perform a mixing of the RF signal with the LO signal to provide a mixed signal, the switching being perform by using a plurality of switching transistors;
performing active bias of the plurality of switching transistors in a feedback loop provided between the LO input and an output of the mixer, wherein the plurality of switching transistors are biased, without supply of bias from a DC bias current source, to a same voltage via the active bias circuit; and
defining bias signals of the plurality of switching transistors via the feedback loop, which adaptively controls a LO bias voltage of each switching transistor.
20. The method according to claim 19 , wherein the received RF signal is a differential RF signal pair, and wherein the switching step performs mixing with a differential local oscillation signal pair received on the LO input.
21. The method according to claim 19 , wherein at least one of the plurality of switching transistors is a metal oxide semiconductor (MOS) transistor.
22. The method according to claim 19 , wherein at least one of the plurality of switching transistors is a bipolar junction transistor (BJT).
23. The method according to claim 19 , wherein at least one of the plurality of switching transistors is a field effect transistor (FET).
24. The method according to claim 19 , wherein the active bias step includes feeding back a signal through an operational amplifier.
25. The method according to claim 19 , further comprising: canceling a DC offset in signals output by the mixer.
26. method according to claim 19 , further comprising: providing the mixed signal to a load network.
27. The method according to claim 19 , further comprising:
merging a low noise amplifier with the mixer, to provide a folder construction.