Radio Transceiver With IM2 Mitigation
First Claim
Patent Images
1. A transceiver, comprising:
- a transmit path configured to transmit a transmit signal through an antenna, the transmit path including,a power amplifier configured to couple to the antenna, and amplify the transmit signal prior to transmission;
an envelope detector configured to detect an envelope of the transmit, signal at the output of the power amplifier;
a receive path configured to receive a receive signal from the antenna and to output a receive baseband signal, the receive path also receiving a transmit leakage signal from said transmit path, the receive path includinga second order intermodulation (IM2) calculation module configured to square the envelope of the transmit signal to produce an IM2 correction signal, the IM2 correction signal representative of signal distortion caused by the transmit leakage signal;
a summer module to subtract IM2 correction signal from the digital receive signal.
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Abstract
A structure and method to reduce second order intermodulation (IM2) of a receiver in a transceiver is provided. Specifically, the output of a detector in a transmit power control loop is utilized to calculate IM2 and the value is subtracted from a receive path to mitigate IM2 in a wireless communication devices. Alternatively, the detector can be placed in one or more receive paths to include receiver front-end passband variation.
28 Citations
20 Claims
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1. A transceiver, comprising:
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a transmit path configured to transmit a transmit signal through an antenna, the transmit path including, a power amplifier configured to couple to the antenna, and amplify the transmit signal prior to transmission; an envelope detector configured to detect an envelope of the transmit, signal at the output of the power amplifier; a receive path configured to receive a receive signal from the antenna and to output a receive baseband signal, the receive path also receiving a transmit leakage signal from said transmit path, the receive path including a second order intermodulation (IM2) calculation module configured to square the envelope of the transmit signal to produce an IM2 correction signal, the IM2 correction signal representative of signal distortion caused by the transmit leakage signal; a summer module to subtract IM2 correction signal from the digital receive signal. - View Dependent Claims (2, 3, 4, 7, 8)
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- 5. The transceiver of claim I, the duplexer coupled to the transmit path at a first port of the duplexer, the receive path at a second port of the duplexer, and the input port of the antenna at a third port of the duplexer, further comprising a duplexer configured to separate the transmit and receive signals an input port of the antenna.
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9. A transceiver, comprising:
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a transmit path configured to transmit a transmit signal through an antenna, the transmit path including, a power amplifier configured to couple to the antenna and amplify the transmit signal prior to transmission; a receive path configured to receive a receive signal from the antenna and to output a receive baseband signal, the receive path also receiving a transmit leakage signal from the transmit path, the receive path including, an envelope detector configured to detect an envelope of the transmit leakage signal; a second order intermodulation (IM2) calculation module configured to square the envelope of the transmit leakage signal to produce an IM2 correction signal, the IM2 correction signal representative of signal distortion caused by the transmit leakage signal; a summer module to subtract IM2 correction signal from the digital receive signal. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A method for reducing second order intermodulation (IM2) in a receiver portion of a transceiver, comprising:
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detecting an envelope of a transmit signal that is generated in a transmitter portion of the transceiver; converting the detected envelope from an analog signal to a digital signal; filtering the digital signal; squaring the filtered signal to produce an IM2 correction signal, the IM2 signal representative of signal distortion caused by leakage of the transmit signal into the receiver portion of the transceiver; and subtracting the IM2 signal from a received signal to produce a baseband received signal. - View Dependent Claims (18, 19, 20)
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Specification