Hewlett-packard Company

Agilent Technologies, Inc.

Richard P Ryan

Raymond A Birgenheier

Matthew Johnson

Melvin D Humpherys

David L Platt

James B Summers

Kerwin D Kanago

A method and system characterizes an IF response of a receiver under test, such that an effect on the characterization by errors associated with uncertainties in knowledge of an RF stimulus signal used to perform the characterization is reduced. The method includes determining an estimate of an actual IF response of the receiver under test from IF responses of the receiver under test measured at overlapping frequency bands and a set of conversion coefficients computed therefrom, such that the estimate reduces the effect of the errors. The system includes a signal generator, an IF processor, a computer program, and a controller that controls the generator and the processor and executes the computer program. When a receiver under test is characterized, the receiver is connected between the signal generator, the IF processor and the controller. The computer program includes instructions that implement characterizing the receiver IF response.

IF frequency response characterization employing overlapping frequency bands

An RF test set having a concurrent measurement architecture is provided. The RF test set is adapted for testing an RF communications device such as a cellular phone according to a set of RF tests. An RF source and an RF receiver are used to communicate with the cellular phone in order to perform the call processing operations to control the cellular phone while performing parametric measurements according to the RF tests. Concurrent measurements allow operation of concurrent measurement processes and call processing operations to take place in the RF test set in order to decrease the time required for each RF test and to increase measurement throughput of the RF test set.

RF test set with concurrent measurement architecture

A method and apparatus for determining the phase and amplitude accuracy of continuous-phase-modulated signals is described. A modulated RF signal generated by a transmitter is down converted to a relatively low intermediate frequency which is filtered and sampled by a high sampling rate analog-to-digital converter. A digital signal processor processes the digital signals to produce a measured phase function corresponding to the modulated RF signal. From the measured amplitude and phase functions, an estimate of the ideal reference phase function corresponding to the modulated RF signal is calculated and synthesized. The reference phase function is compared to the measured phase function to determine the phase function from which the modulated RF signal phase error and frequency error are computed.

Method and apparatus for measuring modulation accuracy

A method and apparatus for determining the phase and amplitude accuracy of continuous-phase-modulated signals is described. A modulated RF signal generated by a transmitter is down converted to a relatively low intermediate frequency which is filtered and sampled by a high sampling rate analog-to-digital convertor. A digital signal processor processes the digital signals to produce a measured amplitude function and a measured phase function corresponding to the modulated RF signal. From the measured amplitude and phase functions, an ideal phase function corresponding to the modulated RF signal is calculated and synthesized. The ideal phase function is compared to the measured phase function to determine the phase function from which the modulated RF signal phase error and frequency error are computed.

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Spokane, WA, United States of America

Richard P Ryan