Gain boosting for local oscillation distribution circuitry

• US 7,415,286 B2
• Filed: 11/21/2005
• Issued: 08/19/2008
• Est. Priority Date: 04/08/2005
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Behzad, Arya Reza
• Primary Examiner(s): Vuong; Quochien B
• Application Number:
  US11/284,203
• Publication Number:
  US 20060229039A1
• Time in Patent Office: 1,002 Days
• Field of Search: 455/114.2, 455/127.1, 455/127.2, 455/232.1, 455/552.1, 455/553.1, 455/333, 455/41.1, 455/41.2, 370/908, 330/67, 330/177, 330/252, 330/253, 330/254
• US Class Current: 455/553.1
• CPC Class Codes: H03F 2203/45318 the AAC comprising a cross coupling circuit, e.g. two extra transistors cross coupled
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H03F 3/245 with semiconductor devices only
• CPC Class Codes: H03F 3/45188 Non-folded cascode stages
• CPC Class Codes: H04B 1/18 Input circuits, e.g. for coupling to an antenna or a transmission line coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H
• CPC Class Codes: H04B 2001/0408 with power amplifiers

Abstract

A multi-band integrated circuit radio transceiver comprising receive and transmit radio front end circuit blocks further includes a local oscillation generator for generating a local oscillation for use by the receive and transmit radio front end circuit blocks to down convert received RF signals to baseband or low intermediate frequency signals and for use by the transmit front end circuit blocks to up-convert outgoing communication signals to RF, respectively. The transceiver further includes at least one buffering element coupled disposed in the local oscillation path that produces a buffered oscillation based upon the local oscillation to at least one front end circuit block wherein the buffering element includes a differentially arranged amplifier stage having a load and a cross-coupled capacitive element coupled between input and output nodes of the amplifier stage and at least one of an inductive device or a selectable capacitive device.

Claims

1. A multi-band integrated circuit radio transceiver, comprising:

a plurality of receive and transmit radio front end circuit blocks for processing ingoing and outgoing communication signals, respectively;

a local oscillation generator for generating a local oscillation for use by the plurality of receive and transmit radio front end circuit blocks to down convert received RF signals to baseband or low intermediate frequency signals and for use by the plurality of receive and transmit radio front end circuit blocks to up-convert outgoing communication signals to RF, respectively;

at least one buffering element coupled between the local oscillation generator and at least one front end circuit block, which at least one buffering element produces a buffered oscillation based upon the local oscillation to the at least one front end circuit block; and

wherein the at least one buffering element includes;

a differentially arranged amplifier stage having an inductive load operably coupled to an output node of the amplifier stage, the inductive load further including a selectable element to adjust a frequency of operation; and

a cross-coupled capacitive element coupled between an input node and the output node of the amplifier stage, the cross-coupled capacitive element having at least one selectable capacitive element.

2. The multi-band integrated circuit radio transceiver of claim 1 further including a plurality of cross-coupled capacitive elements coupled between input and output nodes of the amplifier stage.

3. The multi-band integrated circuit radio transceiver of claim 2 wherein at least one of the plurality of cross-coupled capacitive elements is selectable.

4. The multi-band integrated circuit radio transceiver of claim 3 further including selection logic for selecting one or more capacitive elements of the selectable cross-coupled capacitive elements to improve gain of the at least one buffering element at a specified frequency of operation and further including at least one selectable element of the inductive load and selection logic for selecting the at least one selectable element.

5. The multi-band integrated circuit radio transceiver of claim 4 wherein the at least one selectable element of the inductive load comprises at least one of a selectable capacitive element and an inductive element comprising selectable inductive values.

6. The multi-band integrated circuit radio transceiver of claim 5 wherein the selection logic is defined by a state logic block, which state logic block generates control signals to select one or more capacitive elements of the selectable cross-coupled capacitive elements.

7. The multi-band integrated circuit radio transceiver of claim 5 further including a resistive element coupled in series with at least one cross-coupled capacitive element wherein the resistive element and at least one cross-coupled capacitive element are operable to provide negative resistance in a feed-forward circuit path formed between the input and output nodes of the amplifier stage.

8. The multi-band integrated circuit radio transceiver of claim 7 wherein the state logic block is operable to select one or more capacitive elements of the selectable cross-coupled capacitive elements to substantially but not completely cancel resistance of the inductive load.

9. The multi-band integrated circuit radio transceiver of claim 7 wherein the resistive element includes at least one selectable resistive element and further wherein the selection logic is operable to generate control commands for selecting at least one selectable resistive element.

10. A multi-band integrated circuit radio transceiver, comprising:

a plurality of receive and transmit radio front end circuit blocks for processing ingoing and outgoing communication signals, respectively;

a local oscillation generator for generating a local oscillation for use by the plurality of receive and transmit radio front end circuit blocks to down convert received RF signals to baseband or low intermediate frequency signals and for use by the plurality of receive and transmit radio front end circuit blocks to up-convert outgoing communication signals to RF, respectively;

at least one buffering element coupled between the local oscillation generator and at least one front end circuit block, which at least one buffering element produces a buffered oscillation based upon the local oscillation to the at least one front end circuit block; and

wherein the at least one buffering element includes;

a differentially arranged amplifier stage having a resistive load; and

a cross-coupled capacitive element coupled between input and output nodes of the amplifier stage.

11. The multi-band integrated circuit radio transceiver of claim 10 further including a plurality of cross-coupled capacitive elements coupled between input and output nodes of the amplifier stage.

12. The multi-band integrated circuit radio transceiver of claim 11 wherein at least one of the plurality of cross-coupled capacitive elements is selectable.

13. The multi-band integrated circuit radio transceiver of claim 12 further including selection logic for selecting one or more capacitive elements of the selectable cross-coupled capacitive elements to improve gain of the at least one buffering element at a specified frequency of operation.

14. The multi-band integrated circuit radio transceiver of claim 13 wherein the selection logic is defined within a processor block, which processor block generates control signals to select one or more capacitive elements of the selectable cross-coupled capacitive elements.

15. The multi-band integrated circuit radio transceiver of claim 13 wherein the selection logic is defined by a state logic block, which state logic block generates control signals to select one or more capacitive elements of the selectable cross-coupled capacitive elements.

16. The multi-band integrated circuit radio transceiver of claim 14 further including a resistive element coupled in series with at least one cross-coupled capacitive element wherein the resistive element and at least one cross-coupled capacitive element are operable to provide negative resistance in a feed-forward circuit path formed between the input and output nodes of the amplifier stage.

17. The multi-band integrated circuit radio transceiver of claim 16 wherein the state logic block is operable to select one or more capacitive elements of the selectable cross-coupled capacitive elements to substantially but not completely cancel resistance of the resistive load.

18. The multi-band integrated circuit radio transceiver of claim 16 wherein the resistive element includes at least one selectable resistive element and further wherein the selection logic is operable to generate control commands for selecting at least one selectable resistive element.

19. A buffering element, comprising:

a differentially arranged amplifier stage;

a cross-coupled first capacitive element bank coupled between input and output nodes of the amplifier stage; and

a cross-coupled resistive element coupled between the input and output nodes of the amplifier stage;

an inductive device operably disposed between a supply and the output node of the amplifier stage;

a second capacitive element bank operably disposed across the inductive device forming a tunable tank with the inductive device; and

wherein the buffering element is operable to receive control commands to operably select at least one selectable capacitive element of the cross-coupled first capacitive element bank to adjust gain of the amplifier stage by increasing negative resistance provided to the input nodes of the buffering element and further operable to receive control commands to operably select at least one capacitive element of the second capacitive bank to tune the tank comprising the second capacitive bank and the inductive device.

20. The buffering element of claim 19 wherein the cross-coupled resistive element includes at least one selectable resistive element to increase negative resistance provided to the input nodes of the buffering element and to increase the gain of the amplifier stage.