Single chip CMOS transmitter/receiver

• US 20010048715A1
• Filed: 07/05/2001
• Published: 12/06/2001
• Est. Priority Date: 07/24/1998
• Status: Active Grant

• Current Assignee: GCT Semiconductor Incorporated
• Original Assignee: GCT Semiconductor Incorporated
• Inventors: Jeong, Deog-Kyoon, Lee, Kyeongho
• Granted Patent: US 6,510,185 B2
• Time in Patent Office: Days
• US Class Current: 375/219
• CPC Class Codes: H03D 7/1441 using field-effect transistors H03D7/145 takes precedence
• CPC Class Codes: H03H 11/22 providing two or more phase shifted output signals, e.g. n-phase output
• CPC Class Codes: H03H 2011/0494 Complex filters
• CPC Class Codes: H03K 9/00 Demodulating pulses which have been modulated with a continuously-variable signal
• CPC Class Codes: H03L 7/0891 the up-down pulses controlling source and sink current generators, e.g. a charge pump
• CPC Class Codes: H03L 7/0995 the oscillator comprising a ring oscillator
• CPC Class Codes: H03L 7/1974 for fractional frequency division
• CPC Class Codes: H04B 1/403 using the same oscillator for generating both the transmitter frequency and the receiver local oscillator frequency

Abstract

A single chip RF communication system and method is provided including a transmitter and a receiver. The RF communication system in accordance with the present invention includes an antenna for receiving transmitting RF signals, a PLL for generating multi-phase clock signals having a frequency different from a carrier frequency in response to the multi-phase clock signals and a reference signal having the carrier frequency, a demodulation-mixing unit for mixing the received RF signals with the multi-phase clock signals having the frequency different from the carrier frequency to output the RF signals having a frequency reduced by the carrier frequency and an A/D converting unit for converting the RF signals from the mixing unit into digital signals.

Claims

1. A method of generating local oscillator signals, comprising:

receiving a reference signal having a reference frequency;

generating a plurality of first clock signals from the reference signal, each first clock signal having a different phase and the first frequency that is less than the reference frequency;

mixing the plurality of first clock signals to generate the plurality of local oscillator signals each having a second higher frequency; and

multiplying a plurality of local oscillator signals with input signals to provide output signals at output terminals.

2. The method of

claim 1

, wherein the mixing combines the plurality of first clock signals to generate the plurality of local oscillator signals having the second frequency substantially the same as the reference frequency, and wherein the input signals have the reference frequency and the output signals are baseband.

3. The method of

claim 1

, wherein the mixing combines the plurality of first clock signals to generate the plurality of local oscillator signals having the second frequency substantially the same as the reference signal, and wherein the input signals are baseband and the output signals have the reference frequency.

4. The method of

claim 1

, wherein an input terminal of a plurality of delay cells coupled in series receives the reference signal and outputs of the delay cells provide the plurality of first clock signals having different phases from the delay cells.

5. The method of

claim 1

, wherein said mixing comprises:

first combining corresponding first clock signals to output a corresponding first local oscillator signal; and

second combining corresponding first clock signals to output a corresponding second local oscillator signal.

6. The method of

claim 1

, wherein the input signals are RF signals, and wherein the local oscillator signals have a frequency greater than one GHz.

7. The method of

claim 1

, wherein the said mixing comprises:

receiving a first subset of the first clock signals;

first transmitting a selected signal according to a first pair of the first subset of the first clock signals;

second transmitting the selected signal according to a second pair of the first subset of the first clock signals;

third transmitting the selected signal according to a third pair of the first subset of the first clock signals; and

receiving the first, second and third transmitted selected signals in a prescribed order to generate a first local oscillator signal at a frequency higher than the first frequency.

8. The method of

claim 1

, further comprising:

modulation mixing the plurality of first clock signals combined as the local oscillator signals with transmission data to modulate the transmission data; and

power amplifying the modulated transmission data and transmitting the data to the transceiver for transmission.

9. The method of

claim 1

, further comprising:

RF filtering received input signals;

amplifying the filtered received input signals with a gain to generate the input signals;

low pass filtering the demodulated selected signals having a reduced frequency;

A/D converting the low pass filtered frequency reduced selected signals into digital signals; and

discrete-time signal processing the digital signals.

10. The method of

claim 1

, wherein the local oscillator signals have a frequency greater than 1 GHz.

11. A method of operating a communication system, comprising:

receiving a reference signal and generating a plurality of first clock signals having N different phases, N being an integer greater than 1, each first clock signal having a first frequency substantially equal to double a second frequency divided by N; and

mixing the plurality of first clock signals to generate at least one local oscillator signal therein having the second frequency, wherein said mixing multiplies the at least one local oscillator signal with input signals to provide output signals at output terminals.

12. The method of

claim 11

, wherein the mixing combines the plurality of first clock signals to generate the plurality of local oscillator signals having the second frequency substantially the same as the reference frequency, and wherein the input signals have the reference frequency and the output signals are baseband.

13. The method of

claim 11

, wherein the mixing combines the plurality of first clock signals to generate the plurality of local oscillator signals having the second frequency substantially the same as the reference signal, and wherein the input signals are baseband and the output signals have the reference frequency.

14. The method of

claim 11

, wherein an input terminal of a plurality of delay cells coupled in series receives the reference signal and outputs of the delay cells provide the plurality of first clock signals having different phases from the delay cells.

15. The method of

claim 11

, wherein the input signals are RF signals, and wherein the local oscillator signals have a frequency greater than one GHz.

16. The method of

claim 11

, wherein said mixing comprises:

receiving a first subset of first clock signals at a combining unit;

switching a selected signal according to a first one of the first subset of first clock signals;

switching the selected signal according to a second one of the first subset of first clock signals;

switching the selected signal according to a third one of the first clock signals; and

combining the selected signal responsive to the first, second and third switching to generate a first local oscillator signal at a frequency higher than the first frequency.

17. The method of

claim 11

, wherein the said mixing comprises:

receiving a first subset of the first clock signals;

first transmitting a selected signal according to a first pair of the first subset of the first clock signals;

second transmitting the selected signal according to a second pair of the first subset of the first clock signals;

third transmitting the selected signal according to a third pair of the first subset of the first clock signals; and

receiving the first, second and third transmitted selected signals to generate a first local oscillator signal at a frequency higher than the first frequency.

18. A method of operating a single chip CMOS RF transceiver, comprising:

receiving a reference signal having a reference frequency;

generating a plurality of first clock signals from the reference signal, each first clock signal having a different phase and the first frequency that is less than the reference frequency;

mixing the plurality of first clock signals to generate the plurality of local oscillator signals each having a second higher frequency; and

multiplying a plurality of local oscillator signals with input signals to provide output signals at output terminals.

19. The method of

claim 18

, wherein the mixing combines the plurality of first clock signals to generate the plurality of local oscillator signals having the second frequency substantially the same as the reference frequency, and wherein the input signals have the reference frequency and the output signals are baseband.

20. The method of

claim 18

, wherein the input signals are RF signals, and wherein the local oscillator signals have a frequency greater than one GHz.