Automatic IIP2 calibration architecture
First Claim
1. A second order intermodulation product (IIP2) calibration system for a wireless device comprising:
- a test signal generator includinga transmitter core circuit including an oscillator circuit for generating a base frequency signal, anda test adaptor circuit for adding an offset signal corresponding to the second order tone to the base frequency signal, the test adaptor circuit generating the first RF signal in response to the base frequency signal;
a receiver path having an input node for receiving the first RF signal, circuits for down-converting the first RF signal into a base band signal based on a receive frequency, and signal processing circuits for generating a digital data signal corresponding to the base band signal, the circuits receiving a compensation signal for minimizing the second order tone; and
a calibration circuit for measuring said second order tone in said digital data signal and for generating the compensation signal.
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Accused Products
Abstract
An integrated automatic IIP2 calibration architecture for wireless transceivers is disclosed. The architecture enables a wireless transceiver to generate a test radio frequency (RF) signal having a second order tone with minimal additional circuitry. In particular, the test RF signal is generated using a combination of native transceiver circuits and test adaptor circuits. Native transceiver circuits are those circuits implemented on the transceiver chip for executing native transceiver functions during normal operation, which can be used for generating the test (RF) signal. Test adaptor circuits are added to the transceiver chip, more specifically to the native circuits, for enabling the native circuits to generate the test RF signal in a self-test mode of operation. Circuits for implementing a particular IIP2 minimizing scheme can be included on the transceiver chip for automatic IIP2 calibration during the self-test mode of operation.
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Citations
18 Claims
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1. A second order intermodulation product (IIP2) calibration system for a wireless device comprising:
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a test signal generator including a transmitter core circuit including an oscillator circuit for generating a base frequency signal, and a test adaptor circuit for adding an offset signal corresponding to the second order tone to the base frequency signal, the test adaptor circuit generating the first RF signal in response to the base frequency signal; a receiver path having an input node for receiving the first RF signal, circuits for down-converting the first RF signal into a base band signal based on a receive frequency, and signal processing circuits for generating a digital data signal corresponding to the base band signal, the circuits receiving a compensation signal for minimizing the second order tone; and a calibration circuit for measuring said second order tone in said digital data signal and for generating the compensation signal. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method for on-chip generation of an radio frequency (RF) test signal having a second order tone, comprising:
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a) generating a base frequency signal from a native circuit; b) generating an offset signal corresponding to the second order tone with a test circuit, the offset signal being a preset digital test signal; c) converting the offset signal into an analog signal; and
,d) mixing the base frequency signal with the offset signal to generate the RF test signal by a native transmit path circuit. - View Dependent Claims (9, 10, 11, 12, 13)
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14. A method for second order intermodulation (IIP2) testing and calibration of a wireless device, comprising:
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a) detecting a calibration event; b) generating a radio frequency (RF) test signal having a second order tone with native circuits of the wireless device by; i) generating a base frequency signal by enabling a transmit clock generator circuit; ii) generating a preset digital test signal corresponding to the second order tone with a test circuit; iii) converting a preset digital test signal into an analog signal that corresponds to an offset signal; and
,iv) mixing the base frequency signal with the offset signal by a native transmit path circuit to generate the RF test signal; c) propagating the RF test signal through a receive path of the wireless device; d) measuring a parameter of the second order tone and generating a corresponding compensation signal; and e) adjusting one or more circuits of the receive path with the compensation signal for minimizing the second order tone. - View Dependent Claims (15, 16, 17, 18)
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Specification