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US 8,284,886 B2Granted
Radio frequency built-in self test for quality monitoring of local oscillator and transmitter
AssigneeTexas Instruments Incorporated
InventorsRobert B. Staszewski, Dirk Leipold, Elida de-Obaldia
Life of this patent
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Abstract
A system and method for low-cost performance and compliance testing of local oscillators and transmitters for wireless RF applications. A preferred embodiment comprises observing a digital signal from within an RF circuit, manipulating the signal with digital signal processing techniques, and determining if the RF circuit passes a test based upon results from the manipulating. Since the signal is clocked at a much lower frequency than an RF output of the RF circuit and the manipulation is performed digitally, testing can be performed at different stages of the production cycle and expensive test equipment can be eliminated.
Claims51
A method for testing a radio frequency (RF) circuit comprising:
- observing a signal from the RF circuit, wherein the signal is a digital signal from within a processing portion of the RF circuit, wherein the signal has a high degree of correlation with an RF output of the RF circuit, and wherein the observing occurs outside of the RF circuit;
- manipulating the signal outside of the RF circuit using other circuitry;
- and producing a metric for the test outside of the RF circuit based on results from the manipulating.
A method for testing a radio frequency (RF) circuit comprising:
- observing a phase error signal from the RF circuit, wherein the phase error signal is a digital signal from within a processing portion of the RF circuit, wherein the phase error signal has a high degree of correlation with an RF output of the RF circuit, wherein the observing occurs outside of the RF circuit, and wherein a transfer function between the phase error signal and the RF output phase is flat within a frequency band of interest;
- manipulating the signal outside of the RF circuit using other circuitry;
- and
- producing a metric for the test outside of the RF circuit based on results from the manipulating.
1 more element
A method for testing a radio frequency (RF) circuit comprising:
- observing a signal from the RF circuit, wherein the signal is a digital signal from within a processing portion of the RF circuit, wherein the signal has a high degree of correlation with an RF output of the RF circuit, wherein the RF circuit is an all-digital circuit, wherein the signal is an output of a gain normalization block in an all-digital phase-locked loop in the RF circuit and wherein the observing occurs outside of the RF circuit;
- manipulating the signal outside of the RF circuit;
- and
- producing a metric for the test outside of the RF circuit based on results from the manipulating.
1 more element
A method for testing a radio frequency (RF) circuit comprising:
- observing a signal from the RF circuit, wherein the signal is a digital signal from within a processing portion of the RF circuit, wherein the signal has a high degree of correlation with an RF output of the RF circuit, and wherein the observing occurs outside of the RF circuit:
- manipulating the signal outside of the RF circuit;
- producing a metric for the test outside of the RF circuit based on results from the manipulating;
- wherein the test is for frequency lock and the signal is the output of a phase detector, and wherein the manipulation comprises comparing a value of the signal over several samples;
- and
- wherein the frequency has been locked when a variance in the magnitude is less than a specified threshold.
3 more elements
A method for testing a radio frequency (RF) circuit containing an all-digital phase-locked loop comprising:
- setting the all-digital phase-locked loop to a certain bandwidth;
- observing a signal from the RF circuit, wherein the signal is a digital signal from within a processing portion of the RF circuit, wherein the signal has a high degree of correlation with an RF output of the RF circuit, and wherein the observing occurs outside of the RF circuit;
- manipulating the signal outside of the RF circuit;
- and
- producing a metric for the test outside of the RF circuit based on results from the manipulating, wherein the test is for estimating phase noise power and the signal is an output of a phase detector, and wherein the manipulating comprises calculating a mean square error of the signal.
2 more elements
A method for testing a radio frequency (RF) circuit containing an all-digital phase-locked loop comprising:
- setting the all-digital phase-locked loop to a certain bandwidth;
- observing a signal from the RF circuit, wherein the signal is a digital signal from within a processing portion of the RF circuit, wherein the signal has a high degree of correlation with an RF output of the RF circuit, and wherein the observing occurs outside of the RF circuit;
- manipulating the signal outside of the RF circuit;
- and
- producing a metric for the test outside of the RF circuit based on results from the manipulating, wherein the test is for estimating phase noise power and the signal is an output of a phase detector, wherein the manipulating comprises calculating a mean square error of the signal, wherein the setting, observing, and manipulating is repeated for several different all-digital phase-locked loop bandwidths, and wherein the producing comprises subtracting the calculated mean square errors for the several different all-digital phase-lock loop bandwidths.
2 more elements
A circuit comprising:
- a processor coupled to a radio frequency (RF) circuit, the processor containing circuitry to manipulate digital signals from the RF circuit to provide a performance metric for the RF circuit, the digital signals having a high degree of correlation with an RF output of the RF circuit;
- and
- a control signal input coupled to the processor, wherein the control signal input can enable an observation and manipulation of the digital signals.
A circuit comprising:
- a reference phase accumulator coupled to a signal input, the reference phase accumulator containing circuitry to compute a reference phase;
- a phase detector coupled to the reference phase accumulator, the phase detector containing circuitry to compute a difference between the reference phase and a variable phase;
- a digitally-controlled oscillator (DCO) coupled to the phase detector, wherein the performance of the DCO can be ascertained by a test circuit outside of the circuit observing an output of the phase detector, wherein the test circuit manipulates the observed output and generates a performance metric for the DCO based, at least in part, on the manipulation;
- and
- a variable phase accumulator coupled to the DCO and the phase detector, the variable phase accumulator containing circuitry to compute the variable phase.
2 more elements
A circuit comprising:
- a reference phase accumulator coupled to a signal input, the reference phase accumulator containing circuitry to compute a reference phase;
- a phase detector coupled to the reference phase accumulator, the phase detector containing circuitry to compute a difference between the reference phase and a variable phase;
- a digitally-controlled oscillator (DCO) coupled to the phase detector, wherein the performance of the DCO can be ascertained by a test circuit outside of the circuit observing an output of the phase detector, wherein the test circuit manipulates the observed output and generates a performance metric for the DCO based, at least in part, on the manipulation;
- a variable phase accumulator coupled to the DCO and the phase detector, the variable phase accumulator containing circuitry to compute the variable phase;
- and
- a loop filter coupled to the phase detector and the DCO, the loop filter to provide a desired amount of attenuation to the computed difference between the reference phase and the variable phase, wherein the loop filter is of a type selected from a group consisting of a finite impulse response filter, an infinite impulse response filter or combination thereof.
3 more elements
A method for operating a cellular phone, comprising:
- performing built-in self-test (BIST) on a phase error trajectory parameter associated with the cellular phone;
- and
- reporting to a cellular service provider through a wireless medium when the BIST reports the phase error trajectory parameter to be degraded beyond a limit.
Dependencies are inferred from the claim text.