Wireless local area network (WLAN) using universal frequency translation technology including multi-phase embodiments
Frequency translation and applications of the same are described herein, including RF modem and wireless local area network (WLAN) applications. In embodiments, the WLAN invention includes an antenna, an LNA/PA module, a receiver, a transmitter, a control signal generator, a demodulation/modulation facilitation module, and a MAC interface. The WLAN receiver includes at least one universal frequency translation module that frequency down-converts a received EM signal. In embodiments, the UFT based receiver is configured in a multi-phase embodiment to reduce or eliminate re-radiation that is caused by DC offset. The WLAN transmitter includes at least one universal frequency translation module that frequency up-converts a baseband signal in preparation for transmission over the wireless LAN. In embodiments, the UFT based transmitter is configured in a differential and multi-phase embodiment to reduce carrier insertion and spectral growth.
1. A wireless modem apparatus, comprising:
a balanced transmitter for up-converting a baseband signal, said balanced transmitter including,
an inverter, to receive said baseband signal and generate an inverted baseband signal;
a first controlled switch, coupled to a non-inverting output of said inverter, said first controlled switch to sample said baseband signal according to a first control signal, resulting in a first harmonically rich signal;
a second controlled switch, coupled to an inverting output of said inverter, said second controlled switch to sample said inverted baseband signal according to a second control signal, resulting in a second harmonically rich signal; and
a combiner, coupled to an output of said first controlled switch and an output of said second controlled switch, said combiner to combine said first harmonically rich signal and said second harmonically rich signal, resulting in a third harmonically rich signal.
2. The wireless modem apparatus of claim 1 , wherein the first control signal and second control signal are phase shifted with respect to each other.
3. The wireless modem apparatus of claim 2 , wherein the first control signal and the second control signal are phase shifted by 180 degrees relative to each other.
4. The wireless modem apparatus of claim 1 , wherein the first control signal and the second control signal are configured to improve energy transfer to a desired harmonic of the third harmonically rich signal.
5. The wireless modem apparatus of claim 4 , wherein a pulse width of the first control signal and the second control signal is configured to improve energy transfer to a desired harmonic of the third harmonically rich signal.
6. The wireless modem apparatus of claim 1 , wherein the first control signal and the second control signal have a sampling frequency derived from a master clock signal of the balanced transmitter.
7. The wireless modem apparatus of claim 6 , wherein said sampling frequency is equal to a sub-harmonic of the third harmonically rich signal.
8. The wireless modem apparatus of claim 6 , wherein the first harmonically rich signal and the second harmonically rich signal each includes a plurality of harmonic images, repeating at harmonics of said sampling frequency.
9. The wireless modem apparatus of claim 8 , wherein the relative amplitude of said plurality of harmonic images is a function of a pulse width of the first control signal and the second control signal.
10. The wireless modem apparatus of claim 8 , wherein the relative amplitude of a particular harmonic image of said plurality of harmonic images can be adjusted by adjusting said pulse width of the first control signal and the second control signal.
11. The wireless modem apparatus of claim 8 , wherein energy transfer into higher frequency harmonics of said plurality of harmonic images is increased by reducing said pulse width of the first control signal and the second control signal.
12. The wireless modem apparatus of claim 8 , wherein energy transfer into lower frequency harmonics of said plurality of harmonic images is increased by increasing said pulse width of the first control signal and the second control signal.
13. The wireless modem apparatus of claim 1 , wherein said balanced transmitter further comprises:
a control signal generator that generates the first control signal and the second control signal.
14. The wireless modem apparatus of claim 1 , wherein the third harmonically rich signal includes multiple harmonic images, wherein each of said images contains the baseband information of the baseband signal.
15. The wireless modem apparatus of claim 14 , wherein said balanced transmitter further comprises:
a bandpass filter that selects for transmission one or more harmonic images of interest from said multiple harmonic images.
16. A method for up-converting a baseband signal, comprising:
receiving a baseband signal at an inverter;
inverting said baseband signal to generate an inverted baseband signal;
sampling said baseband signal according to a first control signal to generate a first harmonically rich signal;
sampling said inverted baseband signal according to a second control signal to generate a second harmonically rich signal; and
combining said first harmonically rich signal and said second harmonically rich signal to generate a third harmonically rich signal.
17. The method of claim 16 , wherein the first control signal and the second control signal are configured to improve energy transfer to a desired harmonic of the third harmonically rich signal.
18. The method of claim 16 , wherein a pulse width of the first control signal and the second control signal is configured to improve energy transfer to a desired harmonic of the third harmonically rich signal.
19. The method of claim 16 , wherein the first harmonically rich signal and the second harmonically rich signal each includes a plurality of harmonic images, repeating at harmonics of a sampling frequency of the first control signal and the second control signal.
20. The method of claim 19 , wherein the relative amplitude of a particular harmonic image of said plurality of harmonic images can be adjusted by adjusting a pulse width of the first control signal and the second control signal.