Abstract: Two ends of a transmission line whose electrical characteristics per unit length are known are connected to associated measurement ports of a network analyzer. A short standard is shunt-connected to at least three points in the longitudinal direction of the transmission line, and electrical characteristics are measured in a short-circuited state, thereby calculating error factors of a measurement system. Then an electronic device to be measured is shunt-connected to the transmission line, and electrical characteristics of the electronic device are measured. Then the error factors of the measurement system are removed from the measured values of the electronic device to be measured, thereby obtaining true values of the electrical characteristics of the electronic device to be measured. Accordingly, a highly accurate high-frequency electrical characteristic measuring method that is not affected by connection variations can be implemented.

Abstract: The present invention relates to a measurement arrangement for determining the characteristic line parameters by measuring the S-parameters as a function of the frequency of an electrical signal line that achieves an increased measurement bandwidth, namely a measurement bandwidth >4 GHz. To achieve this the electrical signal line under test has several neighboring signal lines which are connected to ground on one side and left open on the opposite side in an alternating manner.

Abstract: A plurality of signal conductors and ground conductors are connected to associated measurement ports of a network analyzer. A short standard is connected between each of the signal conductors and the ground conductor at least three points in the longitudinal direction of each of the signal conductors, and an electrical characteristic is measured. A through chip is connected in series between the signal conductors, and electrical characteristics are measured. Error factors of a measurement system including a transmission line are calculated. An electronic device to be measured is connected between the signal conductors or among the signal conductors and the ground conductors, and electrical characteristics are measured. The error factors of the measurement system are removed from the measured values, thereby obtaining true values of the electrical characteristics of the electronic device to be measured.

Abstract: A measurement system for circuit parameters of a device under test (DUT) that reduces the number of attachments and detachments of calibration kits. An error factor acquisition device includes a first calibrator connected to ports of a network analyzer that has a first state realization unit that determines open-circuit, short-circuit, and standard load states for the ports. Second calibrators connected to the first calibrator and the DUT have a second state realization unit that determines open-circuit, short-circuit, and standard load states for the ports. The first calibrator includes first connection units that connect the ports to the first state realization unit or to the respective second calibrators, while the second calibrators respectively include a second connection unit that connects the ports to the second state realization unit or the DUT.

Abstract: In a receiving-side printed circuit board, a reflected-waveform analyzing unit analyzes a reflected wave generated in a transmission line on a backplane along with transmission of a signal from a transmitting-side printed circuit board, and acquires waveform data that indicates a waveform of the reflected wave. An input signal identifying unit calculates a size of the reflected wave that is currently received based on the waveform data and data on previously received signals. The input signal identifying unit corrects a threshold value by the calculated size, and identifies a state of a bit indicated by the signal from the transmitting-side printed circuit board.

Abstract: A method and system of calibrating first and second adapters comprises the steps of calibrating coaxial ports of a vector network analyzer to traceable standards and connecting a symmetrical through circuit path between the coaxial ports. The through circuit path comprises a cascaded combination of the first and second adapters. The first adapter is passive and substantially identical to the second adapter and uncascaded first and second adapters comprise a measurement device path. The through circuit path and the measurement device path have substantially equivalent S-parameters. S-parameters of the through circuit path are measured and then the first and second adapters are characterized based upon the measured S-parameters. The method and system may be applied to two port adapters and devices under test and may also be scaled for multi-port adapters and devices under test.

Abstract: In one embodiment, a vector network analyzer (VNA) comprises a plurality of ports for coupling to a device under test (DUT), at least one reference receiver for measuring signals associated with the DUT, and logic for processing measurement data from the at least one reference receiver to compensate for transmission line effects, wherein the logic for processing evaluates a function, of several controllable variables, that is a sum of multiple transmission line models, wherein each of the controllable variables is related to a respective transmission line length associated with a corresponding transmission line model.

Abstract: In a method, computer program and system for determining an operational limit of a power transmission line, time-stamped current phasor information and voltage phasor information for a first end and a second end of the line are determined, an ohmic resistance of the line is computed from the phasor information, and an average line temperature is computed from the ohmic resistance. This allows to determine the average line temperature without dedicated temperature sensors. The average line temperature represents the actual average temperature and is largely independent of assumptions regarding line parameters.

Abstract: A system and method for providing improved isolation between sampling channels in a vector network analyzer and sampling circuit. A vector network analyzer sampling channel includes a non-linear transmission line, an isolation device, a band-pass filter, and a sampler. The nonlinear transmission line receives a continuous-wave driving signal and generates a shockwave from which a pulse signal is generated. The pulse signal is used to gate the sampler and thus sample an RF signal. The isolation device and band-pass filter provide reverse isolation for RF signals traveling in the reverse direction within the channel and prevent RF signal leakage between vector network analyzer channels. The isolation device may include an isolator, amplifier or other reverse isolation device, and is used in conjunction with a band-pass filter. The band-pass filter is used to pass a frequency band for driving the non-linear transmission line.

Abstract: One disclosed embodiment may include a method that includes providing a first set S-parameters for a path of a first substrate having a first port and a second port and providing a second set of S-parameters for a path of a second substrate having a first port and a second port. Waveform parameters are measured for an aggregate path that includes the path of the first substrate, the path of the second substrate, and a structure interconnecting the first and second substrates to provide a third set of S-parameters. A fourth set of S-parameters is calculated for the structure interconnecting the first and second substrates based on the first, second, and third sets of S-parameters.

Abstract: A four-port junction is substituted for a six-port junction in a frequency domain reflectometer, which reduces the parts count and therefore cost and size of the reflectometer while improving reliability. The frequency domain reflectometer can alternatively be used as an insertion loss tester. An algorithm including the Hilbert Transform is used to directly calculate the estimated reflection coefficient from the output power measured at only two output ports.

Abstract: A test system and method characterize a balanced device under test (DUT) with a vector network analyzer (VNA) measurement system using a differential or balanced stimulus signal and further calibrate the VNA using conventional calibration standards. An effect of errors introduced by an uncalibrated portion of the measurement system, such as test fixturing and hybrid junction coupling, is de-embedded from measured S-parameters for the DUT. The method includes calibrating the VNA, characterizing the uncalibrated portion, measuring S-parameters for the DUT with the calibrated VNA, and de-embedding the uncalibrated portion characterization from the S-parameter measurements. The test system includes a multiport VNA measurement system that includes a hybrid coupler, an optional test fixture, and a computer program. A processor executes the computer program. Instructions of the computer program implement the method.

Abstract: Impedance of an unknown load is determined by applying a reference signal from a signal generator through a multi-position switch to the unknown load, a first known calibration impedance, and second known impedance, which can be an open circuit, while measuring the complex voltage developed across each load. The source impedance of the signal generator can be determined from the measurements of the known impedances, and then the unknown impedance can be calculated, using complex voltage divider relationships. The reference signal is applied at one or more frequencies of interest and is preferably a sine wave. Impedance is measured accurately at all frequencies and the limitations of prior art frequency dependant directional-coupler methods of impedance measurement are overcome. The impedance measurement device can be incorporated into a handheld device with a keypad and display.

Abstract: A current-to-voltage converting apparatus connected to an element or a circuit having a first terminal connected to a signal source and comprising a feedback amplifier, which is connected to a second terminal of the element or the circuit and keeps the second terminal at virtual ground, and which converts the current signals that flow to the element or the circuit to voltage signals and outputs these signals; a device for opening the feedback loop of the feedback amplifier and measuring the open-loop loss of the feedback loop; and a compensating amplifier, which compensates for the open-loop loss. It further comprises a device for measuring the open-loop phase shift of the feedback loop when the feedback loop is open and a control unit for keeping the open-loop phase shift at a pre-determined value.

Abstract: A tube measurement and calibration system including a network analyzer for measuring tube radio frequency phase, a calibration adapter for calibrating tube radio frequency power and phase, an amplifier for amplifying input radio frequency power into the tube, and a rigid coaxial cable for radio frequency power communication between the tube and the network analyzer and between the calibration adapter and the network analyzer.

Abstract: An impedance measuring apparatus comprising an automatic balanced bridge has four numerically controlled oscillators that supply sine-wave signals and cosine-wave signals to the quadrature detector and vector modulator of the narrow-band amplifier inside the automatic balanced bridge. The frequency or phase of the output signals of the four numerically controlled oscillators are updated by numeric control from the outside. The four numerically controlled oscillators of the impedance measuring apparatus are oscillators whose frequency or phase is changed a pre-determined time after they have been controlled from the outside. Furthermore, the impedance measuring apparatus has control means with which the change in the frequency or the phase of the output signals of the four numerically controlled oscillators is synchronized.

Abstract: A coaxial radio frequency adapter and method are disclosed. An adapter has a tapered signal pin and a tapered ground sleeve to maintain a consistent impedance and minimize reflections while connecting two elements having different dimensions. A method employs an adapter to characterize losses in a system for evaluating a device under test.

Abstract: The values of the parameters of a large-signal S-parameter model of a device-under-test are determined by using a frequency-offset probe-tone method and by measuring and processing the spectral components of the scattered voltage waves with frequencies equal to the fundamental frequency, the fundamental frequency plus the said frequency offset and the fundamental frequency minus the said frequency offset.

Abstract: An impedance measuring apparatus comprising an automatic balanced bridge has four numerically controlled oscillators that supply sine-wave signals and cosine-wave signals to the quadrature detector and vector modulator of the narrow-band amplifier inside the automatic balanced bridge. The frequency or phase of the output signals of the four numerically controlled oscillators are updated by numeric control from the outside. The four numerically controlled oscillators of the impedance measuring apparatus are oscillators whose frequency or phase is changed a pre-determined time after they have been controlled from the outside. Furthermore, the impedance measuring apparatus has control means with which the change in the frequency or the phase of the output signals of the four numerically controlled oscillators is synchronized.

Abstract: A system and method for providing improved isolation between sampling channels in a vector network analyzer and sampling circuit. A vector network analyzer sampling channel includes a non-linear transmission line, an isolation device, a band-pass filter, and a sampler. The nonlinear transmission line receives a continuous-wave driving signal and generates a shockwave from which a pulse signal is generated. The pulse signal is used to gate the sampler and thus sample an RF signal. The isolation device and band-pass filter provide reverse isolation for RF signals traveling in the reverse direction within the channel and prevent RF signal leakage between vector network analyzer channels. The isolation device may include an isolator, amplifier or other reverse isolation device, and is used in conjunction with a band-pass filter. The band-pass filter is used to pass a frequency band for driving the non-linear transmission line.

Abstract: A method of automatically generating vector sequences for an observability based coverage metric supports design validation. A design validation method for Register Transfer Level (RTL) circuits includes the generation of a tag list. Each tag in the tag list models an error at a location in HDL code at which a variable is assigned a value. Interacting linear and Boolean constraints are generated for the tag, and the set of constraints is solved using an HSAT solver to provide a vector that covers the tag. For each generated vector, tag simulation is performed to determine which others of the tags in the tag list are also covered by that vector. Vectors are generated until all tags have been covered, if possible within predetermined time constraints, thus automatically providing a set of vectors which will propagate errors in the HDL code to an observable output. Performance of the design validation method is enhanced through various heuristics involving path selection and tag magnitude maximization.

Abstract: A current-to-voltage converting apparatus connected to an element or a circuit having a first terminal connected to a signal source and comprising a feedback amplifier, which is connected to a second terminal of the element or the circuit and keeps the second terminal at virtual ground, and which converts the current signals that flow to the element or the circuit to voltage signals and outputs these signals; a device for opening the feedback loop of the feedback amplifier and measuring the open-loop loss of the feedback loop; and a compensating amplifier, which compensates for the open-loop loss. It further comprises a device for measuring the open-loop phase shift of the feedback loop when the feedback loop is open and a control unit for keeping the open-loop phase shift at a pre-determined value.

Abstract: The vector-detecting apparatus of an impedance measuring apparatus comprising a signal source, an automatic balanced bridge, and a vector-detecting apparatus comprises a first and a second filter, whose impulse responses are weighted by a sine function and a cosine function, and the vector of the signals input to the vector-detecting apparatus is determined using the first and second filters. Moreover, the frequency of the signals input to the frequency converter is an integer multiple of the frequency of the signals output from the frequency converter when the input signals are frequency-converted at the step before the vector-detecting apparatus.

Abstract: A method for predicting stability of a closed loop apparatus is disclosed. The closed loop apparatus has an open loop impedance and at least one inherent internal gain. The method comprises the steps of: (a) identifying an impedance scaling factor associated with the closed loop apparatus that may be expressed in terms including the open loop impedance, the at least one inherent internal gain, a gain variable and a phase variable; (b) vectorally establishing a first scaling value for the impedance scaling factor as a function of frequency while maintaining a first variable of the gain variable and the phase variable at a first working value to record the first scaling value for a plurality of frequencies.

Abstract: A system and method for measuring the alternating current series resistance of a conductor when transporting large currents on the order of several thousand amperes. The system comprises a current sensor, a current/voltage converter, a voltage divider, a voltage sensor, a null indicator, and a voltage meter. The alternating current series resistance is measured by measuring a real component of a voltage drop over a predetermined length of the conductor, deriving a measurement current from the conductor, converting the measurement current into a measurement voltage, withdrawing an adjustable portion of voltage from the measurement voltage, comparing the adjustable portion of voltage with the voltage drop, adjusting the adjustable portion of voltage to balance the voltage drop, measuring the alternating current, and determining the resistance of the conductor as a function of the value of the adjustable portion of voltage that balances the voltage drop and the measured alternating current.

Abstract: A load current compensated voltage sampling circuit is characterized by a sampling voltage that is compensated by utilizing different load current values of the detected sample as parameters for transforming into the intended display target value.

Abstract: A method is provided for eliminating the source harmonic component from VNA measurements of the output of a device under test (DUT). A standard vector measurement, GHx, is first measured from the DUT using the VNA. The value GHx is composed of two elements, the DUT's harmonic response to a fundamental input from the source, and the DUT's linear response to the harmonic input from the source. The harmonics from the source which are linearly passed by the DUT, GNx, are then measured with the VNA. The output harmonic generated by the DUT, Hx, is then calculated using vector subtraction according to the equation Hx=GHx−GNx. The output harmonic Hx will then be free from source harmonic components.

Abstract: A method and device for monitoring insulation and fault current in an electrical alternating current network. The differential current formed by vectorial addition is detected between at least two network conductors. Load-cut occurs when the differential current exceeds a specific threshold value. In order to increase safety and to protect human beings, the amount of alternating current contained in the differential current is detected as a first network variable, and the network alternating current between at least both network conductors and between at least one network conductor and an equipotential bonding conductor or a neutral conductor is detected as a second network variable.

Abstract: A pair of terminals across a voltage to be monitored includes, in series, a resistor for developing a low voltage proportional to the high voltage to be monitored, a resistor to develop a voltage indicative of an over-current condition, and a resistance comprising a plurality of resistors which are connectable in parallel with one another, automatically, by remotely actuated switches. When the monitoring system is turned off, the resistances are all automatically set to maximum to minimize the loading on the elevator system. When the monitoring system is first turned on, a preconfiguration routine determines the correct resistance value as that which is the lowest resistance value for which an overcurrent condition does not occur, and this preconfiguration resistance value is stored for future use. Upon subsequent turn on of the monitoring system, all of the resistance values are set at the values determined during the preconfiguration routine.

Abstract: In a vectorial network analyzer having at least two measuring ports, whose measuring arms respectively have quad gates with the accompanying measuring points, a separate high-frequency generator is associated to each measuring port; with high-frequency signals of these generators being distinguishable from each other and being simultaneously fed to their respective measuring ports.

Abstract: A system for the detection of a load modulation signal by inductive coupling includes an antenna circuit having a coil, a circuit for applying an excitation signal having a predetermined frequency to the antenna circuit, and a current sensor for detecting a current signal in the coil. A phase comparator has a first input receiving the excitation signal, and has a second input receiving the current signal detected by the current sensor. The system also includes a circuit for extracting the load modulation signal from a phase signal provided by the phase comparator. The antenna circuit does not form a resonant circuit equal to or near the predetermined frequency of the excitation signal.

Abstract: A method for determining the harmonic response of a device under test (DUT) to the input fundamental frequency component of an input signal is performed on a vector network analyzer. A first response of the DUT at the harmonic frequency is obtained by measuring the linear response of the device at the harmonic frequency of interest after appropriate normalization. A second response of the DUT is obtained by measuring the response of the DUT at the harmonic frequency to an input which comprises a source input fundamental with its harmonic components after appropriate normalization. The harmonic response of the DUT to the source input fundamental alone is computed from the first and second responses. Such computations allow the harmonic response of the DUT to be measured free of stimulus source harmonics, so that overall harmonic measurement accuracy and dynamic range is enhanced.

Abstract: A method for rectifying a sensor current with a synchronous demodulator, wherein the rectifying factor of the synchronous demodulator can be controlled. A control clock pulse signal of the synchronous demodulator is toggled between at least two different states, with the states corresponding to different rectifying factors. The resulting total rectifying factor of the synchronous demodulator can be selected at will by adjusting the pulse duty factor between the at least two states.

Abstract: A method for stabilizing feedback loop in impedance measuring equipment involves determining a null loop transfer function of the impedance measuring device by utilizing multiple independent, known impedances. The phase characteristics of the null loop is measured for each multiple independent, known impedances. Based on the measured phase characteristics, the loop characteristic is determined with regard to impedances of arbitrary devices under test (DUTs). The best phase compensation amount is then computed for use over the entire range of DUTs.

Abstract: A method for determining the degree of hardening of a hardenable material determines the complex electrical permittivity. The .di-elect cons."(t=0)/.di-elect cons."(t) ratio, where .di-elect cons."(t) is the imaginary part of the complex electrical permittivity .di-elect cons.'(t)-j.di-elect cons."(t), is determined as a measure of the strength of the material at an instant in time t. The .di-elect cons.'max/.di-elect cons.'(t) ratio of the real part of the complex permittivity can also be determined as a measure of the strength. These ratios are similar in shape to the curve of the strengths of the hardenable material with time.

Abstract: An impedance measurement system rapidly determines impedance of a sinusoidal signal at a known frequency. The sinusoidal signal can represent a forward voltage, a reflected voltage, a voltage, or a current on a transmission line. The impedance calculation is made by receiving two samples of a signal representing forward voltage and reflected voltage or two samples each of current and voltage. The samples are used to determine an amplitude value and a phase value for the signal. The amplitude and phase value are utilized to calculate the impedance.

Abstract: A vector network analyzer (VNA) has a first harmonic generator multiplying an RF signal by an odd number M1 to produce incident and reflected test signals received at inputs of mixers providing IF signals. A second harmonic generator multiplies an LO signal by an odd number M2 offset by 2 from M1 to provide signals to additional inputs of the mixers providing IF signals. With the harmonic generators providing odd harmonics separated by 2, a single filter removes remaining harmonics from IF signals provided from each mixer. Each harmonic generator includes two step recovery diodes (SRDs) with opposing ends connecting the signal path to ground, the SRDs functioning to cancel even harmonics. A first coupler provides the output of the first harmonic generator to the mixers, the first coupler having a minimal size enabling its output power to increase with frequency.

Abstract: A method for determining whether an electrochemical cell is substantially fully charged. The determination is made by ascertaining the rate of change of the impedance of the cell with changing frequency, at low frequency. A method for determining the state of charge of an electrochemical cell by comparing the impedance of the cell at two or more frequencies or by comparing the impedance of the cell, at a medium frequency, with the impedance at high frequency. Apparatus for generating output signals representative of the magnitude of resistive and reactive components of an impedance (30). The apparatus has a signal generator (70) for passing AC current through the impedance, and a synchronous demodulator circuit (88) for demodulating AC signal appearing across the impedance pursuant to passing the current through it. A phase shift circuit (130, 132, 136, 138, 140) selectively generates control signals in phase or 90.degree.

Abstract: A calibration technique for a vector network analyzer (VNA) enabling calibration standards to be included internal to the VNA. To calibrate the VNA utilizing the internal calibration standards, error terms a, b and c of two two-port error boxes E are defined between the measurement ports and the reflectometer of the VNA wherein a=-det(E), b=e00 and c=e10. Error terms a, b and c are determined by measuring external calibration standards with known reflection coefficients connected directly to the measurement ports. Reflection coefficients for internal calibration standards are then determined using the error terms a, b and c to enable future automatic calibrations. To measure S-parameters of an arbitrary device under test (DUT), one embodiment of the present invention uses the Ferrero technique to measure a reciprocal thru with estimated S.sub.21 characteristics connected between ports A and B to determine an additional error term .alpha. for the error boxes E, where .alpha.=e01.sub.A /e.sub.01B.

Abstract: A circuit measures the driving and circulating current in an H-bridge drive network directly and linearly. Voltage across two current sensing resistors are input to two precision half-wave rectifiers. The output of the rectifiers are input to a differential amplifier via a circuit of resistors. The output of the differential amplifier is a signal representative of the current in the H-bridge for both the driven periods and non-driven or freewheeling periods.

Abstract: An apparatus for identifying and measuring in real time substances overlying a surface comprises a plurality of electrodes, a temperature sensor, an electrode control system connected to the plurality of electrodes for defining an electric field, an amplitude and phase measurement system connected to the plurality of electrodes and to the electrode control system for measuring a plurality of currents responsive to the electric field and converting the currents to a measurement set and computer for storing a map comprising a partition of a vector space of predetermined characteristics of substances into regions of profiles corresponding to the substances which could be overlying the surface. The computer correlates the measurement set with the map thereby identifying and quantifying the substances overlying the surface and generates an output signal corresponding to the identity and quantity of substances overlying the surface.

Abstract: A method for monitoring the condition of electrical-motor-driven devices. The method is achieved by monitoring electrical variables associated with the functioning of an operating motor, applying these electrical variables to a three phase equivalent circuit and determining non-symmetrical faults in the operating motor based upon symmetrical components analysis techniques.

Abstract: A method and a device for measuring compensation balance and imbalance in an electrical supply network having a balancing coil. An auxiliary measurement signal is injected into the network's neutral circuit, changes in the homopolar voltage induced by the auxiliary signal injection are measured, and an impedance measurement is obtained by comparing the changes in the hompolar voltage with the injected auxiliary measurement signal, in terms of both amplitude and phase. A parallel current may advantageously be injected into the neutral circuit at the secondary winding of a homopolar transformer placed in the neutral coil.

Abstract: A multistate electronic transfer standard provides electronic conditions to at least one of two ports of a vector network analyzer. One embodiment of the multistate electronic transfer standard includes a plurality of semiconductor interconnected by transmission lines. Each of the semiconductor devices are biased to generate different conditions at each of the two ports. A control computer controls the biasing of devices according to a predetermined procedure and compares impedance values measured for at least one of the two ports of the network analyzer to known values stored by the control computer. The control computer thereby derives calibration coefficients that are used by the network analyzer in performing further measurements.

Abstract: A calibration technique for a vector network analyzer (VNA) enabling calibration standards to be included internal to the VNA. To calibrate the VNA utilizing the internal calibration standards, error terms a, b and c of two two-port error boxes E are defined between the measurement ports and the reflectometer of the VNA wherein a=-det(E), b=e00 and c=e10. Error terms a, b and c are determined by measuring external calibration standards with known reflection coefficients connected directly to the measurement ports. Reflection coefficients for internal calibration standards are then determined using the error terms a, b and c to enable future automatic calibrations. To measure S-parameters of an arbitrary device under test (DUT), one embodiment of the present invention uses the Ferrero technique to measure a reciprocal thru with estimated S.sub.21 characteristics connected between ports A and B to determine an additional error term .alpha. for the error boxes E, where .alpha.=e01.sub.A /e.sub.01B.

Abstract: The present invention relates to a measuring apparatus for a passive element value using a current vector in which a passive element value is measured by detection of the voltage vector drops at both ends of the passive element and current vectors flowing through the passive element when since waves are applied. The sine wave oscillator applies to a passive measuring element sine waves having a constant maximum value and a constant frequency, and a voltage detecting unit detect a voltage vector drop at the passive measuring element when the sine waves are applied. A current detecting unit then detects a current vector flowing through the passive measuring element, a multiplying circuit unit multiplies an output of the voltage detecting unit to that of the current detecting unit to thereby detect a phase difference between the voltage and the current, and a microcomputer performs an operational process on the passive element value with the voltage vector, current vector and the phase as variables.

Abstract: A multistate electronic transfer standard provides electronic conditions to at least one of two ports of a vector network analyzer. One embodiment of the multistate electronic transfer standard includes a plurality of semiconductor interconnected by transmission lines. Each of the semiconductor devices are biased to generate different conditions at each of the two ports. A control computer controls the biasing of devices according to a predetermined procedure and compares impedance values measured for at least one of the two ports of the network analyzer to known values stored by the control computer. The control computer thereby derives calibration coefficients that are used by the network analyzer in performing further measurements.

Abstract: An impedance meter is not adversely affected by errors originating from changes in characteristics of measurement cables under measurement conditions such as in an environmental test wherein an element to be measured is remote and high and wide measurement frequencies are used. The voltage and the current of an element to be measured are measured to obtain its impedance and the like. A circuit configuration is provided wherein a cable for supplying a measurement signal to the element to be measured and for detecting the current flowing through the element to be measured is a triaxial cable and a cable for detecting the voltage is a coaxial cable, and wherein impedance matching is performed at the ends of the triaxial cable and the coaxial cable on the side of a measuring device and a balun is provided to float an ammeter on a coaxial cable connecting the ammeter-side end of the triaxial cable to the ammeter.

Abstract: A system and method for determining the complex impedance of a load, such as an antenna in an RF transmission system. The system samples both the voltage and current of the signal passing through a transmission line and directly derives digitally the impedance parameters independently of the amplitude or phase of the signal.

Abstract: A method and apparatus for measuring ground to earth impedance at frequencies above dc. A computer controlled instrument is provided for implementing a Three Point Measurement or a Fall of Potential method using three ground paths and a plurality of discrete frequencies in the range of from 5 Hz to 200 MHz. The complex impedance vector array, including absolute value and phase angle, and the real and complex components, for each frequency selected in the range may be determined. The acquired data is evaluated to identify antenna effects to improve the quality of the ground and to select the better ground path.