On-chip receiver sensitivity test mechanism
First Claim
1. A method of testing receiver sensitivity, dynamic range and other BER performance related measures in a frequency modulated transceiver incorporating a local oscillator shared between a transmitter and a receiver, said method comprising the steps of:
- first applying a test sequence to a modulation input of said local oscillator so as to generate a modulated local oscillator signal therefrom;
second applying an unmodulated continuous wave (CW) radio frequency (RF) signal to an RF port of said transceiver, wherein the amplitude of said unmodulated CW RF signal is set to a desired test level;
mixing said unmodulated CW RF signal with said modulated local oscillator signal to generate an IF signal therefrom, said IF signal subsequently processed by said receiver; and
comparing data output of said receiver with said test sequence and generating a bit error rate (BER) result therefrom.
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Accused Products
Abstract
An on-chip receiver sensitivity test mechanism for use in an integrated RF transmitter wherein the transmitter and the receiver share the same oscillator. The mechanism obviates the need to use expensive RF signal generator test equipment with built-in modulation capability and instead permits the use of very low cost external RF test equipment. The invention utilizes circuitry already existing in the transceiver, namely the modulation circuitry and local oscillator, to perform sensitivity testing. The on-chip LO is used to generate the modulated test signal that otherwise would need to be provided by expensive external RF test equipment with modulation capability. The modulated LO signal is mixed with an externally generated unmodulated CW RF signal to generate a modulated signal at IF which is subsequently processed by the remainder of the receiver chain. The recovered data bits are compared using an on-chip BER meter or counter and a BER reading is generated. The BER reading is used either externally or by an on-chip processor or controller to establish a pass/fail indication for the chip.
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Citations
31 Claims
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1. A method of testing receiver sensitivity, dynamic range and other BER performance related measures in a frequency modulated transceiver incorporating a local oscillator shared between a transmitter and a receiver, said method comprising the steps of:
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first applying a test sequence to a modulation input of said local oscillator so as to generate a modulated local oscillator signal therefrom; second applying an unmodulated continuous wave (CW) radio frequency (RF) signal to an RF port of said transceiver, wherein the amplitude of said unmodulated CW RF signal is set to a desired test level; mixing said unmodulated CW RF signal with said modulated local oscillator signal to generate an IF signal therefrom, said IF signal subsequently processed by said receiver; and comparing data output of said receiver with said test sequence and generating a bit error rate (BER) result therefrom. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus for testing receiver sensitivity in a frequency modulated transceiver incorporating a local oscillator shared between a transmitter and a receiver, comprising:
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first means for applying a test sequence to a modulation input of said local oscillator so as to generate a modulated local oscillator signal therefrom; second means for applying an unmodulated continuous wave (CW) radio frequency (RF) signal to an RF port of said transceiver, wherein the amplitude of said unmodulated CW RF signal is set to a desired test level; means for mixing said unmodulated CW RF signal with said modulated local oscillator signal to generate an IF signal therefrom, said IF signal subsequently processed by said receiver; and means for comparing data output of said receiver with said test sequence and generating a bit error rate (BER) result therefrom. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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18. An apparatus for testing receiver sensitivity in a frequency modulated transceiver incorporating a local oscillator shared between a transmitter and a receiver, comprising:
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a sequence generator coupled to a modulation input of said local oscillator, said sequence generator adapted to generate and apply a test sequence to said local oscillator, said local oscillator adapted to output a modulated test signal in response thereto; means for applying an unmodulated continuous wave (CW) radio frequency (RF) signal to an RF input of said receiver, wherein the amplitude of said unmodulated CW RF signal is set to a desired test level; said receiver comprising a mixer adapted to mix said unmodulated CW RF signal with said modulated local oscillator signal so as to generate an IF signal therefrom, wherein said IF signal subsequently processed by said receiver; and a bit error rate (BER) meter coupled to an output of said receiver and adapted to compare data output of said receiver with said test sequence to yield a bit error rate result therefrom. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. A method of testing receiver sensitivity in a transceiver chip incorporating a local oscillator (LO) shared between a transmitter and a receiver, test sequence generator and bit error rate (BER) meter, said method comprising the steps of:
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setting said receiver to a receive mode of operation and enabling modulation of said local oscillator; selecting the output of said test sequence generator as the data source for modulation of said local oscillator and tuning said local oscillator to generate a desired RF channel; setting an external radio frequency (RF) generator to a desired frequency channel and power level; resetting said BER meter and performing test sequence based error counting so as to generate a BER reading once complete; and comparing a BER reading with a specified threshold and passing said chip if said BER reading is less than said threshold, and failing said chip otherwise.
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29. A method of testing and characterizing receiver sensitivity in a transceiver chip incorporating a local oscillator (LO) shared between a transmitter and a receiver, test sequence generator and bit error rate (BER) meter, said method comprising the steps of:
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setting said receiver to a receive mode of operation and enabling modulation of said local oscillator; selecting the output of said test sequence generator as the data source for modulation of said local oscillator and tuning said local oscillator to generate a desired RF channel; sweeping the amplitude setting of an external radio frequency (RF) generator over a predetermined range and measuring BER performance at a plurality of amplitudes; generating a performance curve of BER versus input RF power level; and passing said chip if said measured BER performance is better than a minimum specified performance, and failing said chip otherwise.
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30. A method of testing the highest possible RF input level of a receiver in a transceiver chip incorporating a local oscillator (LO) shared between a transmitter and a receiver, test sequence generator and bit error rate (BER) meter, said method comprising the steps of:
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setting said receiver to a receive mode of operation and enabling modulation of said local oscillator; selecting the output of said test sequence generator as the data source for modulation of said local oscillator and tuning said local oscillator to generate a desired RF channel; setting an external radio frequency (RF) generator to a desired frequency channel and power level; resetting said BER meter and performing test sequence based error counting so as to generate a BER reading once complete; and comparing a BER reading with a specified threshold and passing said chip if said BER reading is less than said threshold, and failing said chip otherwise.
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31. A method of testing the tolerance of a receiver to input frequency errors in a transceiver chip incorporating a local oscillator (LO) shared between a transmitter and a receiver, test sequence generator and bit error rate (BER) meter, said method comprising the steps of:
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setting said receiver to a receive mode of operation and enabling modulation of said local oscillator; selecting the output of said test sequence generator as the data source for modulation of said local oscillator and tuning said local oscillator to generate a desired RF channel; setting an external radio frequency (RF) generator to a desired power level and frequency channel with a deliberate frequency offset equal to the amount of error defined as tolerable in device'"'"'s specifications and; resetting said BER meter and performing test sequence based error counting so as to generate a BER reading once complete; and comparing a BER reading with a specified threshold and passing said chip if said BER reading is less than said threshold, and failing said chip otherwise.
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Specification