Ultrawideband CMOS transceiver

• US 20060103473A1
• Filed: 11/03/2005
• Published: 05/18/2006
• Est. Priority Date: 11/03/2004
• Status: Active Grant

• Current Assignee: Realtek Semiconductor Corp.
• Original Assignee: Wionics Research
• Inventors: Yan, Ran, Aytur, Turgut, Razavi, Behzad, Kang, Han-Chang
• Granted Patent: US 7,986,726 B2
• Time in Patent Office: Days
• US Class Current: 331/2
• CPC Class Codes: H04B 1/7136 Arrangements for generation of hop frequencies, e.g. using a bank of frequency sources, using continuous tuning or using a transform
• CPC Class Codes: H04B 1/7163 using impulse radio
• CPC Class Codes: H04B 1/71635 Transmitter aspects H04B1/7174 takes precedence
• CPC Class Codes: H04B 1/71637 Receiver aspects H04B1/7183 takes precedence
• CPC Class Codes: H04B 2001/71362 using a bank of frequency sources

Abstract

A direct conversion ultrawideband transceiver employing three phase locked loops (PLLs). The PLLs are preferably fixed-frequency PLLs that operate continuously, at different frequencies, with a selected frequency determined by selecting the output of one of the three PLLs. The use of three PLLs is suitable for use in a communication system employing frequency hopping across three bands or sub-bands.

Claims

1. A transceiver for use in an ultrawideband communication system, comprising:

a plurality of phase-locked loops (PLLs), each of the PLLs providing a signal at a different frequency;

a plurality of mixers, each of the mixers configured to mix a signal generated from a corresponding PLL of the plurality of PLLs with a radio frequency signal to thereby downconvert the radio frequency signal to baseband; and

gate circuitry responsive to a selection signal, the gate circuitry gating the signals provided by the PLLs such that only a signal from a single PLL is provided to a mixer at a given time.

2. The transceiver of claim 1 wherein the PLLs are fixed frequency PLLs.

3. The transceiver of claim 1 wherein the PLLs are fixed modulus PLLs.

4. The transceiver of claim 1 further comprising a summer configured to receive and sum signals from the plurality of mixers.

5. The transceiver of claim 1 further comprising a further mixer, the further mixer receiving a baseband signal for transmission and a mixing signal generated from one of the PLLs.

6. The transceiver of claim 5 further comprising additional gate circuitry and a further summer, the additional gate circuitry gating signals generated from the PLLs in response to the selection signal such that only a signal from a single PLL passes the additional gate circuitry, with the further summer configured to receive signals from the gate circuitry, sum the signals, and provide the summed signal to the further mixer as the mixing signal.

7. The transceiver of claim 1 further comprising a low noise amplifier receiving the radio frequency signal and providing an amplified radio frequency signal to the plurality of mixers.

8. The transceiver of claim 7 wherein the low noise amplifier is configured to provide a plurality of amplified radio frequency signals, each of the plurality of amplified radio frequency signals being provided to a corresponding one of the plurality of mixers, the low noise amplifier including a corresponding plurality of amplifiers each coupled to a resonant tank and selectively activated by the selection signal.

9. The transceiver of claim 4 further comprising a filter filtering the summed signal from the summer.

10. A transceiver for use in an ultrawideband communication system communicating data over three frequency sub-bands in a frequency hopping manner, comprising:

three phase-locked loops (PLLs) each providing a mixing signal at a different frequency;

three direct downconvert mixers each receiving an amplified RF signal and a mixing signal from a corresponding one of the three PLLs; and

means for gating the mixing signals from the PLLs responsive to a sub-band select signal such that only a single mixer of the three mixers receives a mixing signal from the PLLs at a selected time.

11. The transceiver of claim 10 further comprising a further mixer, the further mixer upconverting a baseband signal to an RF signal based on a mixing signal from the PLLs;

and

means for gating the mixing signals from the PLLs responsive to the sub-band signal such that the further mixer receives only a single mixing signal from the PLLs at a selected time.

12. A transceiver for use in an ultrawideband communication system, comprising:

a low noise amplifier receiving an RF signal and providing an amplified RF signal;

a plurality of mixers, with a mixer for each sub-band used in the ultrawideband communication system, each of the plurality of mixers receiving a representation of the amplified RF signal and configured to receive a mixing signal for direct downconversion of signals in one of the sub-bands used in the ultrawideband communication system;

a plurality of phase-locked loops (PLLs), with a PLL for each sub-band used in the ultrawideband communication system, each of the PLLs generating a mixing signal for direct downconversion of signals in one of the sub-bands used in the ultrawideband communication system; and

means for gating the mixing signals responsive to a sub-band selection signal such that only a single mixer downconverts a representation of the amplified RF signal.

13. The transceiver of claim 12 further comprising a summer summing output signals from the mixers.

14. The transceiver of claim 13 further comprising a filter filtering the summed output signal.

15. The transceiver of claim 12 further comprising a further mixer upconverting a baseband signal to a radio frequency, the further mixer receiving a mixing signal from the PLLs, with the further mixer receiving a single mixing signal at a selected time.