Abstract: Test and measurement probes include a body, an adjustable member moveably coupled to the body and having a changeable position relative to the body, and a transducer subsystem structured to measure the position of the adjustable member and configured to output a position signal indicative of the position of the adjustable member. A change in the position of the adjustable member causes a change in an electrical characteristic of the probe. A position-dependent correction factor may be used to correct the change in the electrical characteristic. Methods of compensating for a change in a response of a test and measurement system include monitoring a position sensor output to detect a position change of a first part of a probe relative to a second part, determining that the position sensor output value has crossed a boundary value between a first and second range, and applying a compensation factor corresponding to the second range to modify the response of the system.

Abstract: Test and measurement probes include a body, an adjustable member moveably coupled to the body and having a changeable position relative to the body, and a transducer subsystem structured to measure the position of the adjustable member and configured to output a position signal indicative of the position of the adjustable member. A change in the position of the adjustable member causes a change in an electrical characteristic of the probe. A position-dependent correction factor may be used to correct the change in the electrical characteristic. Methods of compensating for a change in a response of a test and measurement system include monitoring a position sensor output to detect a position change of a first part of a probe relative to a second part, determining that the position sensor output value has crossed a boundary value between a first and second range, and applying a compensation factor corresponding to the second range to modify the response of the system.

Abstract: System and methods may allow an operator of a signal measurement instrument to characterize and calibrate a network with unsupported connector types, e.g., not traceable to known standards. Adapters having supported and unsupported interfaces can be used to measure the system responses of networks in a system under test. These measurements can be mathematically cascaded to deduce virtual models that produce an accurate and fully calibrated total system response.

Abstract: A signal acquisition system has a signal acquisition probe having probe tip circuitry coupled to a resistive center conductor signal cable. The resistive center conductor signal cable of the signal acquisition probe is coupled to a compensation system in a signal processing instrument via an input node and input circuitry in the signal processing instrument. The signal acquisition probe and the signal processing instrument have mismatched time constants at the input node with the compensation system having an input amplifier with feedback loop circuitry and a shunt pole-zero pair coupled to the input circuitry providing pole-zero pairs for maintaining flatness over the signal acquisition system frequency bandwidth.

Abstract: A signal acquisition system has a signal acquisition probe having probe tip circuitry coupled to a resistive center conductor signal cable. The resistive center conductor signal cable is coupled to a compensation system in a signal processing instrument via an input node and input circuitry in the signal processing instrument. The signal acquisition probe and the signal processing instrument have mismatched time constants at the input node with the compensation system having an input amplifier with feedback loop circuitry and a compensation digital filter providing pole-zero pairs for maintaining flatness over the signal acquisition system frequency bandwidth.

Abstract: A signal acquisition system has a signal acquisition probe having probe tip circuitry coupled to a resistive center conductor signal cable. The resistive center conductor signal cable of the signal acquisition probe is coupled to a compensation system in a signal processing instrument via an input node and input circuitry in the signal processing instrument. The signal acquisition probe and the signal processing instrument have mismatched time constants at the input node with the compensation system providing pole-zero pairs for maintaining flatness over the signal acquisition system frequency bandwidth.

Abstract: System and methods may allow an operator of a signal measurement instrument to characterize and calibrate a network with unsupported connector types, e.g., not traceable to known standards. Adapters having supported and unsupported interfaces can be used to measure the system responses of networks in a system under test. These measurements can be mathematically cascaded to deduce virtual models that produce an accurate and fully calibrated total system response.

Abstract: A balun structure is disclosed having positive and negative going signal paths coupled to a ninety degree hybrid. The positive signal path has a circuit trace and a phase shaper structure that provides three hundred and sixty degrees of phase shift at Port 1 of the hybrid. The negative going signal path has a circuit trace and a second order phase shaper that provides four hundred and fifty degrees of phase shift at Port 2 of the hybrid. Port 1 is coupled to Port 3 of the hybrid and functions as an output port. The first order phase shaper and the second order phase shaper compensate for the signal loss caused by a signal cable coupled to the output port and provide a frequency band from DC to at least 15 GHz and a transient response having less than ten percent pre-shoot.

Abstract: A signal acquisition system has a signal acquisition probe having probe tip circuitry coupled to a resistive center conductor signal cable. The resistive center conductor signal cable of the signal acquisition probe is coupled to a compensation system in a signal processing instrument via an input node and input circuitry in the signal processing instrument. The signal acquisition probe and the signal processing instrument have mismatched time constants at the input node with the compensation system having an input amplifier with feedback loop circuitry and a shunt pole-zero pair coupled to the input circuitry providing pole-zero pairs for maintaining flatness over the signal acquisition system frequency bandwidth.

Abstract: A test and measurement instrument and method for providing post-acquisition trigger control and presentation of associated waveforms on a display. An electrical signal under test is sampled and digitized, and stored in an acquisition memory as a data record. A display device draws a waveform associated with the signal under test. After the acquisition of the digital samples is stopped, a user selects trigger criteria using trigger controls such as a trigger level control. A trigger circuit detects a post-acquisition trigger event in the data record based on the trigger criteria causing an automatic adjustment of the waveform to conform to a time of the post-acquisition trigger event. One or more configurable trigger controls can be used to adjust a display of post-acquisition trigger events and waveforms. Upon resumption of the live-acquisition of data, the live waveform conforms to the newly selected trigger criteria as previewed during the post-acquisition mode.

Abstract: A signal acquisition system has a signal acquisition probe having probe tip circuitry coupled to a resistive center conductor signal cable with the signal cable coupled to a signal processing instrument via an input node. The input node is coupled to an input current amplifier via input circuitry. The input circuitry provides at least one of resistive and capacitive termination of the resistive center conductor signal cable. The termination of the resistive center conductor signal cable in the signal processing instrument provides a signal acquisition system where the capacitive loading of a device under test at higher frequencies is reduced by reducing the input capacitance of the probe tip circuitry resulting in an increase in the signal acquisition system bandwidth.

Abstract: A signal acquisition system has a signal acquisition probe having probe tip circuitry coupled to a resistive center conductor signal cable. The resistive center conductor signal cable of the signal acquisition probe is coupled to a compensation system in a signal processing instrument via an input node and input circuitry in the signal processing instrument. The signal acquisition probe and the signal processing instrument have mismatched time constants at the input node with the compensation system providing pole-zero pairs for maintaining flatness over the signal acquisition system frequency bandwidth.

Abstract: A balun structure is disclosed having positive and negative going signal paths coupled to a ninety degree hybrid. The positive signal path has a circuit trace and a phase shaper structure that provides three hundred and sixty degrees of phase shift at Port 1 of the hybrid. The negative going signal path has a circuit trace and a second order phase shaper that provides four hundred and fifty degrees of phase shift at Port 2 of the hybrid. Port 1 is coupled to Port 3 of the hybrid and functions as an output port. The first order phase shaper and the second order phase shaper compensate for the signal loss caused by a signal cable coupled to the output port and provide a frequency band from DC to at least 15 GHz and a transient response having less than ten percent pre-shoot.

Abstract: A signal acquisition system has a signal acquisition probe having probe tip circuitry coupled to a resistive center conductor signal cable. The resistive center conductor signal cable is coupled to a compensation system in a signal processing instrument via an input node and input circuitry in the signal processing instrument. The signal acquisition probe and the signal processing instrument have mismatched time constants at the input node with the compensation system having an input amplifier with feedback loop circuitry and a compensation digital filter providing pole-zero pairs for maintaining flatness over the signal acquisition system frequency bandwidth.

Abstract: A signal acquisition system has a signal acquisition probe having probe tip circuitry coupled to a resistive center conductor signal cable. The resistive center conductor signal cable is coupled to a compensation system in a signal processing instrument via an input node and input circuitry in the signal processing instrument. The signal acquisition probe and the signal processing instrument have mismatched time constants at the input node with the compensation system having an input amplifier with feedback loop circuitry and a compensation digital filter providing pole-zero pairs for maintaining flatness over the signal acquisition system frequency bandwidth.

Abstract: A test and measurement instrument and method for providing post-acquisition trigger control and presentation of associated waveforms on a display. An electrical signal under test is sampled and digitized, and stored in an acquisition memory as a data record. A display device draws a waveform associated with the signal under test. After the acquisition of the digital samples is stopped, a user selects trigger criteria using trigger controls such as a trigger level control. A trigger circuit detects a post-acquisition trigger event in the data record based on the trigger criteria causing an automatic adjustment of the waveform to conform to a time of the post-acquisition trigger event. One or more configurable trigger controls can be used to adjust a display of post-acquisition trigger events and waveforms. Upon resumption of the live-acquisition of data, the live waveform conforms to the newly selected trigger criteria as previewed during the post-acquisition mode.

Abstract: A signal acquisition system has a signal acquisition probe having probe tip circuitry coupled to a resistive center conductor signal cable with the signal cable coupled to a signal processing instrument via an input node. The input node is coupled to an input current amplifier via input circuitry. The input circuitry provides at least one of resistive and capacitive termination of the resistive center conductor signal cable. The termination of the resistive center conductor signal cable in the signal processing instrument provides a signal acquisition system where the capacitive loading of a device under test at higher frequencies is reduced by reducing the input capacitance of the probe tip circuitry resulting in an increase in the signal acquisition system bandwidth.

Abstract: A signal acquisition system has a signal acquisition probe having probe tip circuitry coupled to a resistive center conductor signal cable. The resistive center conductor signal cable is coupled to a compensation system in a signal processing instrument via an input node and input circuitry in the signal processing instrument. The signal acquisition probe and the signal processing instrument have mismatched time constants at the input node with the compensation system having an input amplifier with feedback loop circuitry and a compensation digital filter providing pole-zero pairs for maintaining flatness over the signal acquisition system frequency bandwidth.

Abstract: A low capacitance signal acquisition system has a signal acquisition probe having a low capacitance input circuit coupled to a compensation amplifier in a signal processing instrument via a signal cable. The low capacitance input circuit, the signal cable and the signal processing instrument input have mismatched time constants with the compensation amplifier having feedback loop circuitry providing adjustable gain and pole-zero pairs for maintaining flatness over the low capacitance signal acquisition system frequency bandwidth.

Abstract: A signal acquisition system has a signal acquisition probe having probe tip circuitry coupled to a resistive center conductor signal cable. The resistive center conductor signal cable of the signal acquisition probe is coupled to a compensation system in a signal processing instrument via an input node and input circuitry in the signal processing instrument. The signal acquisition probe and the signal processing instrument have mismatched time constants at the input node with the compensation system having an input amplifier with feedback loop circuitry and a shunt pole-zero pair coupled to the input circuitry providing pole-zero pairs for maintaining flatness over the signal acquisition system frequency bandwidth.