Wideband resistive input mixer with noise-cancelled impedance
View Patent ↗A radio frequency (RF) mixing circuit including a quadrature mixer that receives non-overlapping in-phase and quadrature local oscillator (LO) signals, and a plurality of low noise amplifiers (LNAs) operatively connected to the quadrature mixer, the plurality of LNAs presenting an input impedance at a baseband. A first voltage at an input node of the quadrature mixer is equal to a second voltage across the impedance up-converted to a frequency of a LO signal received by the quadrature mixer. The second voltage across the LNA input impedance includes a frequency of an input signal of the quadrature mixer down-converted by a frequency of the in-phase and quadrature LO signals and filtered by the impedance. The quadrature mixer down-converts an input signal by a frequency of the in-phase and quadrature LO signals and transfers the noise cancelled impedance to a RF to achieve a noise cancelled match.
1. A radio frequency (RF) mixing circuit comprising:
a quadrature mixer that receives in-phase and quadrature local oscillator (LO) signals, wherein said quadrature mixer comprises a plurality of metal oxide semiconductor field effect transistor (MOSFET) switches driven by said in-phase and quadrature LO signals, and wherein said plurality of MOSFET switches are connected in parallel to one another, each of said MOSFET switch comprises a gate, a drain, and a source, wherein said drain of each of said MOSFET switch are operatively coupled to one another to receive a RF signal, wherein said source of each of said MOSFET switch are operatively connected to a respective impedance, wherein said gate of each of said MOSFET switch to receive said LO signals for turning on said MOSFET switch, and wherein said quadrature mixer down-converts said RF signal; and
a plurality of low noise amplifiers (LNAs) operatively connected to said quadrature mixer, said plurality of LNAs presenting an input impedance at a baseband, wherein a first voltage at an input node of said quadrature mixer is equal to a second voltage across said impedance up-converted to a frequency of a LO signal received by said quadrature mixer,
wherein said input impedance at a baseband comprises a noise cancelled impedance.
2. A radio frequency (RF) mixing circuit comprising:
a quadrature mixer that receives in-phase and quadrature local oscillator (LO) signals, wherein said quadrature mixer comprises a plurality of metal oxide semiconductor field effect transistor (MOSFET) switches driven by said in-phase and quadrature LO signals, and wherein said plurality of MOSFET switches are connected in parallel to one another, each of said MOSFET switch comprises a gate, a drain, and a source, wherein said drain of each of said MOSFET switch are operatively coupled to one another to receive a RF signal, wherein said source of each of said MOSFET switch are operatively connected to a respective impedance, wherein said gate of each of said MOSFET switch to receive said LO signals for turning on said MOSFET switch, and wherein said quadrature mixer down-converts said RF signal; and
a plurality of low noise amplifiers (LNAs) operatively connected to said quadrature mixer, said plurality of LNAs presenting an input impedance at a baseband, wherein a first voltage at an input node of said quadrature mixer is equal to a second voltage across said impedance up-converted to a frequency of a LO signal received by said quadrature mixer, wherein said second voltage across the LNA input impedance comprises a frequency of an input signal of said quadrature mixer down-converted by a frequency of said in-phase and quadrature LO signals and filtered by said impedance.
3. The RF mixing circuit of claim 1 , wherein said quadrature mixer down-converts an input signal by a frequency of said in-phase and quadrature LO signals and transfers said noise cancelled impedance to a RF to achieve a noise cancelled match, wherein said noise cancelled match comprises a resistive match.
4. The RF mixing circuit of claim 1 , wherein each LNA input impedance comprises at least one of a resistor and a capacitor, and said resistor is connected either in a parallel combination or a series combination with said capacitor.
5. A radio frequency (RF) mixing circuit comprising:
a quadrature mixer that receives in-phase and quadrature local oscillator (LO) signals, wherein said quadrature mixer comprises a plurality of metal oxide semiconductor field effect transistor (MOSFET) switches driven by said in-phase and quadrature LO signals, and wherein said plurality of MOSFET switches are connected in parallel to one another, each of said MOSFET switch comprises a gate, a drain, and a source, wherein said drain of each of said MOSFET switch are operatively coupled to one another to receive a RF signal, wherein said source of each of said MOSFET switch are operatively connected to a respective impedance, wherein said gate of each of said MOSFET switch to receive said LO signals for turning on said MOSFET switch, and wherein said quadrature mixer down-converts said RF signal; and
a plurality of low noise amplifiers (LNAs) operatively connected to said quadrature mixer, said plurality of LNAs presenting an input impedance at a baseband, wherein a first voltage at an input node of said quadrature mixer is equal to a second voltage across said impedance up-converted to a frequency of a LO signal received by said quadrature mixer, wherein each LNA input impedance comprises:
a first component comprising a first resistor in parallel with a first capacitor; and
a second component comprising an active impedance, wherein said first component is connected in at least one of a parallel combination and a series combination with said second component.
6. The RF mixing circuit of claim 1 , wherein said in-phase and quadrature LO signals comprises four independent non-overlapping in-phase and quadrature LO signals.
7. The RF mixing circuit of claim 6 , wherein said LO signals turn off said MOSFET switch.
8. The RF mixing circuit of claim 5 , wherein said input impedance at a baseband comprises a noise cancelled impedance.
9. A circuit comprising a plurality of metal oxide semiconductor field effect transistor (MOSFET) switches connected in parallel to one another and driven by independent in-phase and quadrature local oscillator (LO) signals, wherein a drain of each MOSFET switch is operatively coupled to one another to receive a signal, wherein a source of each of said MOSFET switch is operatively connected to a respective impedance, wherein a gate of each of said MOSFET switch receives said LO signals for turning on said MOSFET switch, and wherein said impedance comprises a noise cancelled impedance.
10. A method of filtering signals in a wireless network system, said method comprising:
receiving a radio frequency (RF) signal;
performing a down-conversion of said RF signal to in-phase and quadrature baseband signals, wherein said RF signal is down-converted by a quadrature mixer; and
transferring an impedance to RF to achieve a noise cancelled match, wherein said noise cancelled match is a resistive match,
wherein said quadrature mixer comprises a plurality of metal oxide semiconductor field effect transistor (MOSFET) switches driven by in-phase and quadrature local oscillator (LO) baseband signals, wherein said plurality of MOSFET switches are connected in parallel to one another, each of said MOSFET switch comprises a gate, a drain, and a source, wherein said drain of each of said MOSFET switch are operatively coupled to one another to receive said RF signal, wherein said source of each of said MOSFET switch are operatively connected to a respective impedance, and wherein said gate of each of said MOSFET switch to receive a LO signal for turning on said MOSFET switch, and
wherein said impedance is transferred based on an up-converted impedance of said quadrature mixer.
11. The method of claim 10 , wherein said impedance comprises a Miller-multiplied resistance.
12. The method of claim 10 , wherein said impedance is the input impedance of a plurality of low noise amplifiers (LNAs).
13. The method of claim 10 , wherein said in-phase and quadrature LO signals comprises four independent non-overlapping in-phase and quadrature LO signals.
14. The method of claim 13 , wherein said LO signals turn off said MOSFET switch.
15. The method of claim 10 , wherein said impedance comprises a noise cancelled impedance.
16. The circuit of claim 9 , wherein said independent in-phase and quadrature local oscillator (LO) signals comprises four independent non-overlapping in-phase and quadrature LO signals, and wherein said LO signals turn off said MOSFET switch.
17. The method of claim 14 , wherein said in-phase and quadrature LO signals comprises four independent non-overlapping in-phase and quadrature LO signals, and wherein said LO signal turns off said MOSFET switch.
18. The RF mixing circuit of claim 2 , wherein said input impedance comprises a noise cancelled impedance.