Methods and apparatus for time-domain measurement with a high frequency circuit analyzer

A method of calibrating a measurement system for measuring the response of an electronic device to a high frequency input signal, the method comprising the steps of:

• providing a measurement system including a measurement unit for measuring high frequency signals and including a signal path connected to at least one input of the measurement unit and enabling the measurement unit to be connected to a port of a device,
• ascertaining first calibration data regarding the measurement system,
• the first calibration data enabling, when the measurement system is connected to a device to which signals are applied, the processing of the resulting signals, said resulting signals being representative of independent waveforms at a port of the device resulting from the applied signals, the waveforms being measured by the measurement system via the signal path, to compensate for the influence of the measurement system on the independent waveforms between the port of the device and the input of the measurement unit, the first calibration data being sufficient to enable signals representative of a function of the independent waveforms at the port of the device to be calculated, and
• ascertaining second calibration data concerning said function, so that when the measurement system is used to measure the behavior of a device to which it is, in use, connected, the signals as measured by the measurement unit may be processed with the use of the first and second calibration data to produce output signals from which the absolute values of the magnitude and phase of waves at the port of the device may be directly ascertained, wherein
• the method includes ascertaining the second calibration data by making measurements with a real network, the real network being connected to a portion of the signal path that in use connects to the port of the device, the influence of the real network on the measurements made with the real network being known.

A method of measuring the response of an electronic device to a high frequency input signal, the method comprising the steps of:

• a) providing an electronic device having a first port and a second port, the ports being able to receive and/or send high frequency signals,
• b) providing a measurement system including a measurement unit for measuring high frequency signals and including a first signal path connecting the measurement unit to the first port of the device and a second signal path connecting the measurement unit to the second port of the device,
• c) applying one or more signals to the device, measuring with the measurement unit via the first signal path two independent waveforms at the first port of the device and measuring with the measurement unit via the second signal path two independent waveforms at the second port of the device, and
• d) processing signals representative of the waveforms as measured by the measurement system, with the use of calibration data, to compensate for the influence of the measurement system on the two independent waveforms between the ports of the device and the measurement unit to produce output signals from which the absolute values of the magnitude and phase of waves at the first port of the device and the absolute values of the magnitude and phase of waves at the second port of the device may be directly ascertained, wherein the calibration data includes data ascertained by making measurements with a real network, the real network being connected to a portion of the signal path that in use is able to connects to at least one of the ports of the device, the influence of the real network on the measurements made with the real network being known.

A method of calibrating a measurement system for measuring the response of a two port electronic device to a high frequency input signal, the method comprising the steps of;

• providing a measurement system including a measurement unit for measuring high frequency signals and including a first signal path connected to a first input port of the measurement unit and enabling the measurement unit to be connected to a first port of a device and a second signal path connected to a second input port of the measurement unit and enabling the measurement unit to be connected to a second port of a device,
• ascertaining first calibration data regarding the measurement system, the first calibration data being sufficient to enable signals representative of waveforms measured at the input ports of the measurement unit to be processed to compensate for the influence of the measurement system on the waveforms between i) the parts of the signal paths for connecting to the ports of a device and ii) the input ports of the measurement unit so that in use of the measurement system signals representative of a function of waves at the fist and second ports of a device under test may be produced, and
• ascertaining second calibration data concerning said function, by making measurements with a real network, the real network being connected to a portion of the signal path that in use is able to connect to at least one of the ports of the device, the influence of the real network on the measurements made with the real network being known, wherein
• when the measurement system is used to measure the behavior of a device, signals as measured by the measurement unit may be processed with the use of the first and second calibration data to produce output signals from which the absolute values of the magnitude and phase of waves at the first port of the device and the absolute values of the magnitude and phase of waves at the second port of the device may be directly ascertained.

A method of measuring the response of an electronic device to a high frequency input signal, the method comprising the steps of:

• 1) providing an electronic device having a first port and a second port, the ports being able to receive and/or send high frequency signals, the device being suitable for use as a high power amplifying device in a mobile telecommunications base station,
• 2) providing a measurement system including a measurement unit for measuring high frequency signals and including a first signal path connecting the measurement unit to the first port of the device and a second signal path connecting the measurement unit to the second port of the device,
• 3) applying one or more signals to the device, so as to effect an active harmonic load pull on the device, measuring with the measurement unit via the first signal path two independent waveforms at the first port of the device and measuring with the measurement unit via the second signal path two independent waveforms at the second port of the device, and
• 4) processing signals representative of the waves as measured by the measurement system to compensate for the influence of the measurement system on the two independent waveforms between i) the ports of the device and ii) the measurement unit and to extract output signals from which the absolute values of the magnitude and phase of waves at the first port of the device and the absolute values of the magnitude and phase of waves at the second port of the device may be directly ascertained, wherein
• the processing of the signals includes making use of data that has been ascertained by making measurements with a real network, the real network being connected to a portion of the signal path that in use is able to connect to at least one of the ports of the device, the influence of the real network on the measurements made with the real network being known.

A method of measuring the response of an electronic device to a high frequency input signal, the method comprising the steps of:

• i) providing an electronic device having a port,
• ii) providing a microwave transition analyzer (MTA) and connecting the MTA to the port of the device,
• iii) applying a high frequency signal to the device and measuring with the MTA two independent waveforms, the waveforms being measured at the MTA, and the MTA producing output signals as a result of the measurements made by the MTA, and
• iv) processing the output signals from the MTA with the use of an error model to produce data representative of current and/or voltage time-domain waveforms at the port, wherein
• the error model used in the processing of the output signals is a non-directional network error model and comprises parameters which have been previously ascertained.

Waveforn analyzer for measuring the response of an electronic device to a high frequency input signal, the analyzer including:

• an input connection for connecting to a port of a device to be analyzed,
• a measurement system including a measurement unit and a signal path, the signal path connecting the measurement unit to the input connection, the analyzer being so arranged that the measurement unit is able to measure in use via the signal path independent waveforms at the port of the device,
• a signal generator able to send high frequency signals to a port of a device to be analyzed,
• a processor connected to the measurement system, and
• a data store for holding data accessible by the processor, wherein
• the processor is programmed to be able, in use of the analyzer:
• to process signals received from the measurement unit,
• to access calibration data held in the data store,
• to process data representative of waves as measured by the measurement system, and
• to compensate, with the use of the calibration data, for the influence of the measurement system on the waves between the port of the device and the measurement unit, and to produce output data from which the absolute values of the magnitude and phase of waves at the port of the device may be directly ascertained, and
• wherein the processor is so programmed and the analyzer is so arranged that at least a portion of said calibration data may be ascertained by making measurements with a real network, the real network being connected to a portion of the signal path that in use connects to the port of the device, the influence of the real network on the measurements made with the real network being known.

Waveform analyzer for measuring the response of an electronic device to a high frequency input signal, the analyzer including:

• connection means for connecting to one or more ports of a device to be analyzed,
• measuring means for measuring via one or more signal paths independent waveforms at the connection means,
• signal generating means for sending high frequency signals to a port of the device to be analyzed,
• processing means for processing signals from the measuring means, and
• calibrating means for ascertaining calibration data, wherein, in use of the analyzer when at least one port of a device is connected to the connection means, the device receiving signals from the signal generating means, the processing means is able:
• to process data representative of waves as measured by the measuring means, both to compensate for the difference between the independent waveforms as measured and the waves at the or each of said one or more ports, and to produce output data from which the absolute values of the magnitude and phase of waves at the or each of said one Or more ports of the device may be directly ascertained, and wherein
• the analyzer is so arranged that the processor makes use of data that has been ascertained by making measurements with a real network, the real network being connected to a portion of the signal path that in use connects to the port of the device, the influence of the real network on the measurements made with the real network being known.