CMOS wireless transceiver with programmable characteristics

• US 7,120,427 B1
• Filed: 03/11/2002
• Issued: 10/10/2006
• Est. Priority Date: 03/19/2001
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Systems Wireless Networking (Australia) Pty Limited (Cisco Systems, Inc.)
• Inventors: Adams, Andrew R., Weste, Neil H.
• Primary Examiner(s): Anderson, Matthew D.
• Assistant Examiner(s): PHU, SANH D
• Application Number:
  US10/095,504
• Time in Patent Office: 1,674 Days
• Field of Search: 455/251.1, 455/76, 455/86, 455/87, 455/418, 375/238, 375/376
• US Class Current: 455/418
• CPC Class Codes: H03F 1/0261 with control of the polarisation voltage or current, e.g. gliding Class A
• CPC Class Codes: H03F 3/19 with semiconductor devices only
• CPC Class Codes: H03F 3/68 Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics power amplifiers using a combination of several semiconductor amplifiers H03F3/211; combinations of amplifiers using coupling networks with distributed constants H03F3/602
• CPC Class Codes: H04B 1/0014 using DSP [Digital Signal Processor] quadrature modulation and demodulation
• CPC Class Codes: H04B 1/40 Circuits
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

A monolithic radio integrated circuit includes a substrate, a set of one or more analog subcircuits on the substrate, a programmable bias current supply on the substrate coupled to the set to provide bias currents to the analog subcircuits of the set including programmable bias currents to one or more analog subcircuits forming a first subset of the set, and a digital subsection coupled to the programmable bias supply to determine the bias currents supplied to the analog subcircuits of the first subset, such that one or more characteristics of the radio integrated circuit are modifiable by programming the programmable bias supply.

Claims

1. A radio frequency (RF) integrated circuit comprising:

a substrate;

a set of one or more analog subcircuits on the substrate; and

a programmable bias current supply on the substrate coupled to the subcircuit set to provide bias currents to the analog subcircuits, including providing programmable bias current to each of one or more analog subcircuits forming a first subset of the set,

such that one or more characteristics of the RF integrated circuit are modifiable by programming the programmable bias supply.

2. An integrated circuit as described in claim 1, further comprising:

a digital controller coupled to the programmable bias supply to set the bias current supplied to each of the one or more analog subcircuits of the first subset.

3. An integrated circuit as described in claim 2, wherein the integrated circuit is for operation as a radio transceiver including a receiver and a transmitter,

the integrated circuit further comprising:

a temperature sensor coupled to the digital controller to provide an indication of temperature;

wherein the controller automatically performs a calibration experiment when the temperature changes by a temperature change threshold, such that the integrated circuit remains within a specification.

4. An integrated circuit as described in claim 3, further comprising:

an analog-to-digital converter between the temperature sensor and the digital controller to provide digital samples of the temperature indication to the digital controller.

5. An integrated circuit as described in claim 3, wherein the integrated circuit includes one or more variable gain elements coupled to the digital controller, wherein the digital controller further is to vary the gain of at least one of the variable gain elements, and wherein the calibration experiment includes a gain calibration experiment to determine the gain modification for at least one of the variable gain elements to maintain the integrated circuit within the specification.

6. An integrated circuit as described in claim 5, wherein the controller includes a processor having a memory and an interrupt mechanism that causes a gain calibration interrupt routine to run on the processor when an interrupt occurs to operate the gain calibration experiment and to store the temperature indication in the memory, and wherein an interrupt occurs when the temperature changes from the last stored temperature indication by the temperature change threshold.

7. An integrated circuit as described in claim 3, further comprising:

one or more tunable frequency synthesizers each including a tunable voltage controlled oscillator (VCO),

wherein the calibration experiment tunes the VCOs of the frequency synthesizers such that the integrated circuit remains within the specification.

8. An integrated circuit as described in claim 2, wherein the integrated circuit is for operation as a radio transceiver including a receiver and a transmitter,

the integrated circuit further comprising:

one or more tunable filters coupled to the digital controller such that the digital controller is further to tune the one or more filters,

wherein the digital controller is to perform a calibration experiment to determine the filter settings that are required for the integrated circuit to meet a specification.

9. An integrated circuit as described in claim 8, further comprising:

a temperature sensor coupled to the digital controller to provide an indication of temperature;

wherein the controller automatically performs the calibration experiment when the temperature changes by a temperature change threshold such that chip remains within the specification.

10. An integrated circuit as described in claim 9, wherein the controller includes a processor having a memory and an interrupt mechanism that causes a filter calibration interrupt routine to run on the processor when an interrupt occurs to operate the calibration experiment and to store the temperature indication in the memory, and wherein an interrupt occurs when the temperature changes from the last stored temperature indication by the temperature change threshold.

11. An integrated circuit as described in claim 10, wherein the integrated circuit includes one or more variable gain elements coupled to the digital controller,

wherein the digital controller further is to vary the gain of at least one of the variable gain elements, and wherein the calibration interrupt routine also includes a gain calibration routine to modify the gains of at least one of the variable gain elements to maintain the chip within the specification.

12. An integrated circuit as described in claim 2,

wherein the integrated circuit is for operation as a radio transceiver including a receiver and a transmitter, the receiver including one or more receive analog subcircuits, and the transmitter including one or more transmit analog subcircuits, and

wherein the subset includes at least one of the receive analog subcircuits, such that the digital controller is to set the bias supplied to at least one of the receive analog subcircuits.

13. An integrated circuit as described in claim 1, wherein the set includes subcircuits fabricated in a metal oxide semiconductor technology.

14. An integrated circuit as described in claim 13, wherein the metal oxide semiconductor technology is CMOS technology.

15. An integrated circuit as described in claim 12, further comprising:

a digital controller coupled to the programmable bias supply to set the bias current supplied to one or more of the subcircuits; and

a temperature sensor coupled to the controller to provide an indication of temperature,

wherein the controller is to set the bias level to the LNA dynamically according to temperature so that the LNA gain remains within a specification as the temperature changes.

16. A method of calibrating a radio frequency (RF) integrated circuit (IC), the IC including:

a substrate;

a set of one or more analog subcircuits on the substrate; and

a programmable bias current supply on the substrate coupled to the subcircuit set to provide bias currents to the analog subcircuits, including providing programmable bias current to each of one or more analog subcircuits forming a first subset of the set;

the method comprising modifying the bias to one or more of the analog subcircuits to modify one or more characteristics of the IC, such that the IC meets a specification.

17. A method as recited in claim 16, wherein the bias modification is to account for one or more of temperature variation and process variation.

18. A method as recited in claim 16, further comprising;

sensing the temperature to provide an indication of temperature; and

performing a calibration experiment when the temperature indication indicates that the temperature has changed by more than a settable temperature change threshold.