Wireless communication device with a low noise receiver
A wireless communication device includes a radio frequency antenna and a transceiver. The transceiver includes a receiver having a switching architecture configured to generate a plurality of output phases within a local oscillator period based on the filtered RF signal and a respective plurality of local oscillator signals. The plurality of output phases can be organized into at least K groups where K is an integer of four or greater, and each nth group of the K groups includes nth and (n+K)th output phases of the plurality of output phases. The receiver can difference the nth and (n+K)th output phases of each respective group of the K groups, resulting in gain-added output phases.
1. A wireless communication device comprising:
a radio frequency antenna; and
a transceiver including a baseband subsystem and a receiver, the receiver coupled between the antenna and the baseband subsystem and including a filter, the filter configured to implement low pass filtering and gain functions on a radio frequency signal and to output a filtered radio frequency signal, the receiver further including a downconverter configured to generate a plurality of output phases within a local oscillator period based on (i) the filtered radio frequency signal and (ii) a respective plurality of local oscillator signals, the plurality of output phases organized into at least K groups where K is an integer of four or greater, each nth group of the K groups including nth and (n+K)th output phases of the plurality of output phases, n being an integer between 0 and K−1, and the receiver further including a differencing stage configured to difference the nth and (n+K)th output phases of each respective group of the K groups, resulting in gain-added output phases, the filter further configured to provide impedance matching at an input of the downconverter, the impedance matching providing a step up in voltage by a factor of a square root of the ratio of an input impedance of the downconverter to an input impedance at an input to the filter.
2. The wireless communication device of claim 1 wherein the downconverter provides a gain of at least approximately 6 decibels.
3. The wireless communication device of claim 1 wherein the receiver does not include a surface acoustic wave filter.
4. The wireless communication device of claim 3 wherein the receiver does not include a low noise amplifier for amplifying the radio frequency signal.
5. The wireless communication device of claim 1 wherein K is a power of 2.
6. The wireless communication device of claim 1 wherein K is 4, 8, or 16.
7. The wireless communication device of claim 1 wherein K is a multiple of 4.
8. A radio frequency receiver comprising:
a filter configured to low pass filter a radio frequency signal and output a filtered radio frequency signal;
a downconverter configured to generate a plurality of output phases within a local oscillator period based on the filtered radio frequency signal, the plurality of output phases organized into at least K groups where K is an integer of four or greater, where each nth group of the K groups includes nth and (n+K)th output phases of the plurality of output phases, and where n is an integer between 0 and K−1; and
a differencing circuit configured to difference the nth and (n+K)th output phases of each respective group of the K groups, resulting in gain-added output phases, the filter configured to provide impedance matching at an input of the downconverter, the impedance matching providing a step up in voltage by a factor of a square root of the ratio of an input impedance of the downconverter to an input impedance at an input to the filter.
9. The radio frequency receiver of claim 8 wherein K is a power of 2.
10. The radio frequency receiver of claim 8 wherein K is 4, 8, or 16.
11. The radio frequency receiver of claim 8 wherein K is a multiple of four.
12. The radio frequency receiver of claim 8 wherein the plurality of output phases includes 8 or 16 output phases.
13. The radio frequency receiver of claim 8 wherein the downconverter provides a gain of at least approximately 6 decibels.
14. The radio frequency receiver of claim 8 wherein the receiver does not include a surface acoustic wave filter or a low noise amplifier for amplifying the radio frequency signal.
15. A wireless communication device comprising:
an antenna configured to wirelessly transmit and receive radio frequency signals; and
a receiver in communication with the antenna including a filter and a downconverter, the filter configured to output a filtered radio frequency signal, the downconverter configured to generate a plurality of output phases within a local oscillator period based on the filtered radio frequency signal, the plurality of output phases organized into at least K groups where K is an integer of four or greater, each nth group of the K groups includes nth and (n+K)th output phases of the plurality of output phases, where n is an integer between 0 and K−1, the receiver further including a differencing stage configured to difference the nth and (n+K)th output phases of each respective group of the K groups, resulting in gain-added output phases of the filtered radio frequency signal, the filter configured to provide impedance matching at an input of the downconverter, the impedance matching providing a step up in voltage by a factor of a square root of the ratio of an input impedance of the downconverter to an input impedance at an input to the filter.
16. The wireless communication device of claim 15 wherein K is a power of 2.
17. The wireless communication device of claim 15 wherein K is 4, 8, or 16.
18. The wireless communication device of claim 15 wherein the plurality of output phases includes 8 or 16 output phases.
19. The wireless communication device of claim 15 wherein the downconverter provides a gain of at least approximately 6 decibels.
20. The wireless communication device of claim 15 wherein the receiver does not include a surface acoustic wave filter or a low noise amplifier for amplifying the radio frequency signal.