Abstract: A hybrid type transceiver for broadband large area beamforming is provided. A communication device includes: antennas; first phase shifters (PSs) configured to adjust respective phases of reception signals received via the antennas; and a first time delay (TD) configured to adjust delays for the reception signals the phases of which are adjusted at the first PSs. Accordingly, in designing a broadband communication system using a large area array antenna, the structure of the system can be simplified, a size can be reduced, power consumption can be reduced, and a resolution of the system can be enhanced.

Abstract: A driving method of a display device includes sequentially outputting a plurality of eye tuning signals, receiving a plurality of checking information obtained from a data driving circuit, wherein the checking information indicates whether the data driving circuit is operating in response to each of the plurality of eye tuning signals, and selecting one optimal eye tuning signal among the plurality of eye tuning signals operating the data driving circuit on the basis of the checking information. Image signals are output on the basis of condition information of the optimal eye tuning signal.

Abstract: An apparatus and method for measuring the properties of a DUT characterized by a signal gain applied to an input signal to that DUT and a DUT noise spectrum introduced by that DUT is disclosed. An apparatus includes first and second measurement channels and a controller. The first and second measurement channels are characterized by gains and noise spectrums that are different for the different channels and generate first and second measurement signals. The controller measures an average value of a product of the first and second measurement signals when an input signal is applied to the input of the DUT, the controller providing a measure of the signal to noise ratio of the output of the DUT, independent of the noise spectrums in the first and second measurement channels. Four channel embodiments reduce the amount of calibration needed to measure the gain and noise spectrum of the DUT.

Abstract: To prevent an excessive current from flowing through a device under test. A test apparatus that tests a device under test, comprising a power supply section that generates a power supply voltage to be supplied to the device under test; an inductive load section that is provided in a path leading from the power supply section to the device under test; a first semiconductor switch that is provided in the path leading from the inductive load section to the device under test and is connected in parallel with the device under test; and a control section that turns the first semiconductor switch ON when supply of the power supply voltage to the device under test is stopped.

Abstract: Apparatuses and methods of input attenuator circuits are described. One sensing circuit includes an attenuator circuit to receive a signal from an electrode of a sense array. The attenuator circuit is configured to attenuate input current of the signal. The attenuator circuit includes an attenuation matrix including an input terminal to receive the signal and multiple resistors. The attenuation matrix is configured to split the input current into an output current of the attenuation signal on a first output terminal and a second output current on a second output terminal. The attenuation matrix is to output the attenuated signal on the first output terminal to an integrator of the sensing circuit. The attenuator circuit also includes a buffer coupled between the attenuation matrix and the integrator. The buffer is configured to maintain a substantially same voltage at the first output terminal and the second output terminal.

Abstract: In one aspect, a method to detect an object in an area includes forming a wireless network among a plurality of nodes, each of the nodes being configured to generate an electromagnetic field (EMF) in the area and determining changes in the EMF between two nodes based on: a first difference in received signal strength values between a previously determined received signal strength value and a currently determined received signal strength value, a second difference in received signal strength values between the currently determined received signal strength value and an average received signal strength value and a third difference in link quality values between a previously determined link quality value and a currently determined link quality value. The method further comprises detecting the object based on the changes in the EMF.

Abstract: A method and system for detecting corrosion metal loss. One may provide a guided wave probe that includes an electromechanical device and a corrosion probe. This may be followed by measuring a baseline guided wave attenuation value of the corrosion probe with no corrosion. One may then periodically measure the guided wave attenuation of the corrosion probe and detect an increase in guided wave attenuation values and identify metal corrosion associated with the increase in guided wave attenuation values. This may then be followed by estimating the corrosion metal loss of the metallic component.

Abstract: A proximity sensor includes a relatively simple health monitoring circuit. The proximity sensor includes a variable gain oscillator, a feedback circuit, and a proximity determination circuit. The variable gain oscillator has a gain that varies with the proximity of a target to a sensor coil, generates an oscillating electrical signal having a substantially constant amplitude magnitude, and generates an energy signal representative of the electrical energy needed to sustain oscillations. The feedback circuit supplies feedback to the oscillator, and the proximity determination circuit, based on the energy signal, supplies a proximity signal representative of target proximity to the sensor coil. The health monitor circuit also receives the oscillating electrical signal and supplies a health status signal representative of proximity sensor health.

Abstract: A proximity sensor includes a relatively simple temperature compensation circuit, and includes a variable gain oscillator, a temperature sensor circuit, and a proximity determination circuit. The variable gain oscillator has a gain that varies with the proximity of a target to a sensor coil, generates an oscillating electrical signal having a substantially constant amplitude magnitude, and generates an energy signal representative of the electrical energy needed to sustain oscillations. The temperature compensation circuit senses proximity sensor temperature and supplies a temperature signal representative thereof, and the proximity determination circuit, based on the energy signal, supplies a proximity signal representative of target proximity to the sensor coil. The proximity determination circuit includes a comparator and a fixed resistor network. The comparator circuit supplies the proximity signal.

Abstract: An embodiment is a method for de-embedding. The method comprises forming a primary structure in a semiconductor chip and forming an auxiliary structure in the semiconductor chip. The auxiliary structure replicates a first portion of the primary structure. The method further comprises determining a transmission matrix for each of the primary structure and the auxiliary structure based on measurements and extracting a transmission matrix of a first component of the primary structure by determining a product of the transmission matrix of the primary structure and an inverse of the transmission matrix of the auxiliary structure.

Abstract: A noise measurement system in a power stabilization network, a variable filter applied to the power stabilization network, and a method for measuring noise in the power stabilization network are provided. A power line communication signal from the power stabilization network is attenuated relative to a particular frequency using a filter in order to allow the power line communication signal to operate within an input range of an Electromagnetic Interference (EMI) measurer. A signal from a forbidden frequency band is transmitted to the EMI measurer without any attenuation or influence on a noise floor.

Abstract: A test structure for testing electrical properties of a material comprises a first loop and a second loop, which are connected to form a closed test loop. A signal generator, for generating a test signal, is coupled to the first loop and the second loop. A signal propagation switching logic is coupled to the first loop and to the second loop for alternatingly flipping the test signal between the first and second loops, such that the test signal moves uninterrupted through the closed test loop. A probe logic detects any degradation of the test signal as the test signal travels along the closed test loop.

Abstract: A system and apparatus for compensating cable losses in a video signal transmission system includes feedback circuits to determine the spectral attenuation of a received signal and to control an equalizer circuit to amplify selected frequencies of the received signal, and to determine the various times of arrival of two or more video signals and selectively adjust one or more delay lines to reduce the differences in their arrival times.

Abstract: The system contains a circuit apparatus and method for monitoring the status of components within a digital system, the apparatus having a digital device. A power-line is supplied to the digital device. A second signal is rendered from the power-line. At least one mask pulse is generated from a third signal. An extraction device is situated to extract a component of the power-line. A filtering device is situated to receive the extracted component. An extracted signal is output by the filtering device, wherein the extracted signal is a correlated result having characteristics corresponding to the status of components in a digital system.

Abstract: To calibrate a bandpass filter, a received signal strength corresponding to a received communication channel is determined. A variable element of the bandpass filter is adjusted based on the received signal strength of the received communication channel to calibrate the bandpass filter.

Abstract: A proximity sensor includes a relatively simple health monitoring circuit. The proximity sensor includes a variable gain oscillator, a feedback circuit, and a proximity determination circuit. The variable gain oscillator has a gain that varies with the proximity of a target to a sensor coil, generates an oscillating electrical signal having a substantially constant amplitude magnitude, and generates an energy signal representative of the electrical energy needed to sustain oscillations. The feedback circuit supplies feedback to the oscillator, and the proximity determination circuit, based on the energy signal, supplies a proximity signal representative of target proximity to the sensor coil. The health monitor circuit also receives the oscillating electrical signal and supplies a health status signal representative of proximity sensor health.

Abstract: A cable testing system that tests cable includes a pulse generation module that transmits a first pulse on a first communications channel of the cable. A sampling module waits a predetermined time period after the pulse generation module transmits the first pulse and then detects a first amplitude of a reflected signal on a second communications channel of the cable. A time domain reflection (TDR) module receives the first amplitude and verifies proper operation of the cable based on the first amplitude. The predetermined time period corresponds with an estimated roundtrip propagation delay of the first pulse when the first pulse is reflected back to the cable testing system after traveling a first predetermined distance along the cable. The sampling module incrementally increases the predetermined time period during subsequent iterations of a cable test in order to verify proper operation of a predetermined segment of the cable.

Abstract: A transmission line driving circuit that can support a high-rate signal transmission and further can perform appropriate loss compensation in accordance with a signal pattern. A transmission line driving circuit 1 comprises a plurality of driver input circuits 20 that serve as signal analyzing unit for analyzing the content of the signal pattern of an input signal; a plurality of lowpass filters 30; a plurality of gain adjusting circuits 40; a plurality of adders 50; and adder 52; and a driver output circuit 60 that outputs, in accordance with a signal analysis result, a signal the phase of which has been adjusted in such a direction that cancels the timing deviation caused by a loss occurring when the input signal is transmitted to the transmission path. The output signal from the driver output circuit 60 is transmitted to the transmission path 2.

Abstract: A method for manufacturing an equalizer used to compensate a digital signal passed by a transmission line, in which the digital signal can be presented as a frequency-domain function. The method includes measuring a the transmission line scattering-parameter; performing an integration and a differentiation about the transmission line scattering-parameter, the frequency-domain function, the ideal gain, and an equalizer scattering-parameter to get the component impedances of the equalizer; and manufacturing the equalizer circuit with the derived component impedances.

Abstract: A method is disclosed for calibrating a capacitance of an apparatus for measuring dielectric properties of a part. The apparatus includes an electrically grounded chamber, a lower electrode disposed within the chamber and connected to a radiofrequency (RF) transmission rod, an electrically grounded upper electrode disposed within the chamber above the lower electrode, and a variable capacitor connected to control transmission of RF power through the RF transmission rod to the lower electrode. A method is also disclosed for determining a capacitance of a part through use of the apparatus. A method is also disclosed for determining a dielectric constant of a part through use of the apparatus. A method is also disclosed for determining a loss tangent of a part through use of the apparatus.

Abstract: A method is disclosed for at least partly determining and/or adapting an attenuation map used for attenuation correction of Positron Emission Tomography image data sets in a combined Magnetic Resonance-Positron Emission Tomography device. In at least one embodiment of the method, at least one one-dimensional magnetic resonance data set of a patient is recorded along one imaging direction; the boundaries of at least one part of the body of the patient intersected by the imaging direction are determined from the one-dimensional magnetic resonance data set; and the attenuation map is determined and/or adapted at least partly as a function of the boundaries determined.

Abstract: A control circuit for scanning a pressure or force responsive sensor array is disclosed. Pressure or force sensors formed of an array of pressure or force responsive sensor elements can be used to acquire pressure or force measurements in response to an applied load. The control circuit can sample signals from the sensor elements to detect the pressure or force at one or more sensor elements of the sensor array. The circuit herein may provide for relatively faster scan rates. A user may define a subset or subsets of sensor elements of the sensor array to be scanned. Various methods and related circuitry for adjusting for sensor characteristics are also disclosed.

Abstract: An apparatus and method are provided for reducing noise in a capacitive sensor (200). One apparatus includes a gain stage (210) including an output, the gain stage configured to generate a first signal having a noise component and a second signal having a desired output component and the noise component, and a filtered-sampling stage (250) having an input coupled to the gain stage output, the filtered-sampling stage configured to sample the first signal, store the first signal, and subtract the first signal from the second signal to produce a desired output signal. A method includes generating a first signal having a first noise component of the gain stage (710), storing the first signal (725), generating a second signal comprising a desired output component and the first noise component (730), and subtracting the first signal from the second signal to produce a first output signal having the desired output component (750).

Abstract: A system for determining insertion loss of a telephone line under test (LUT) is responsive to electrical stimulation of an input of the LUT at each frequency of a first plurality of discrete frequencies for determining values of at least two of Rs, Cs, Rp and Cp at each frequency, wherein Rs and Cs represent an equivalent series RC input impedance of the LUT and Rp and Cp represent an equivalent parallel RC input impedance of the LUT. The system determines an insertion loss value of the LUT as a function of a value of one of Rs, Cs, Rp and Cp determined at one frequency of the first plurality of frequencies and a value of another one of Rs, Cs, Rp and Cp at another frequency of the first plurality of frequencies.

Abstract: Noise discrimination in signals from a plurality of sensors is conducted by enhancing the phase difference in the signals such that off-axis pick-up is suppressed while on-axis pick-up is enhanced. Alternatively, attenuation/expansion are applied to the signals in a phase difference dependent manner, consistent with suppression of off-axis pick-up and on-axis enhancement. Nulls between sensitivity lobes are widened, effectively narrowing the sensitivity lobes and improving directionality and noise discrimination.

Abstract: A method for calibrating a filter begins with the filter filtering a first signal having a first frequency to produce a first filtered signal, wherein the first frequency is in a known pass region of the filter. The processing continues by measuring signal strength of the first filtered signal to produce a first measured signal strength. The processing continues with the filter filtering a second signal having a second frequency to produce a second filtered signal, wherein the second frequency is at a desired corner frequency of the filter. The processing continues by measuring signal strength of the second filtered signal to produce a second measured signal strength. The processing continues by comparing the first measured signal strength with the second measured signal strength to determine whether the filter has attenuated the second signal by a desired attenuation value with respect to the first signal.

Abstract: A method of correcting distortions resulting from loss and dispersion in cable fault measurements. A cable is measured in the frequency domain to obtain a reflected response. Fractional sinusoidal components of the reflected response having attenuated amplitude and delayed phase values at points defining the junctures of adjacent equal predetermined lengths are collected and normalized. Then the fractional sinusoidal components of the reflected response are extracted from normalized sum by mathematically calculating the real value at each point, thereby removing all loss and dispersion distortion components.

Abstract: The system and method of determining insertion loss of a telephone line under test (LUT) determines a first insertion loss as a function of plurality of different equivalent circuit values of the LUT determined at a plurality of different frequencies of a first set of discrete frequencies. A running standard deviation (rSTD) of a predicted length d of the LUT at each frequency of a second set of discrete frequencies is determined from the predicted lengths d of the LUT at and below said frequency. A second insertion loss is determined based on the pair of adjacent discrete frequencies of the second set of discrete frequencies that have the largest difference between their rSTDs. Based on a comparison of the first and second insertion losses to an expected insertion loss, one of these insertion losses is deemed to be the actual insertion loss of the LUT.

Abstract: The invention concerns a method and a device for phase calculation from attenuation values using a Hilbert transform for reflectometric measurements in the frequency domain. The invention is characterized in that the measuring system comprises a signal source for a measurement signal, a coupling element connected to the signal source, and an object to be measured connected to the coupling element. The part of the measurement signal reflected by the object to be measured is uncoupled via the coupling element and measured at a collector. The invention is further characterized in that an attenuator is mounted in the signal path, between the coupling element and the object to be measured. The attenuator can also be comprised in the coupling element.

Abstract: A method for calibrating a filter begins with the filter filtering a first signal having a first frequency to produce a first filtered signal, wherein the first frequency is in a known pass region of the filter. The processing continues by measuring signal strength of the first filtered signal to produce a first measured signal strength. The processing continues with the filter filtering a second signal having a second frequency to produce a second filtered signal, wherein the second frequency is at a desired corner frequency of the filter. The processing continues by measuring signal strength of the second filtered signal to produce a second measured signal strength. The processing continues by comparing the first measured signal strength with the second measured signal strength to determine whether the filter has attenuated the second signal by a desired attenuation value with respect to the first signal.

Abstract: Attenuation of a pulsed signal traversing a cable is assessed by identifying a pulse in a signal received after traversing the cable and determining first and second reference signal levels in dependence upon characteristics of the pulse. A measurement is made of the slope of the pulse between the first and second reference signal levels (such as 25% and 75% of the peak pulse magnitude), and this measurement is used to determine an indication of the cable attenuation. The cable attenuation may in turn be used to determine a threshold for indicating loss of signal during a measurement operation.

Abstract: Measuring a signal includes setting a gain numerator of a gain value and setting a gain denominator of the gain value, where the gain value is a ratio of the gain numerator to the gain denominator. An input signal is received and adjusted in accordance to the gain value to yield an output signal. The input signal is determined using the output signal and a reciprocal of the gain value, where the reciprocal is a ratio of the gain denominator to the gain numerator.

Abstract: In a method for evaluating a crystalline semiconductor substrate which includes a collector layer, a base layer, and an emitter layer and is used for a heterojunction bipolar transistor, a layer is provided having the same composition as the base layer. The semiconductor substrate is irradiated with excitation light and change with time in intensity of photoluminescence from the layer is measured before the intensity becomes saturated. The change with time in current gain of the heterojunction bipolar transistor produced using the semiconductor substrate is determined from the change with time in the intensity.

Abstract: A RF power measurement circuit for measuring RF power of a pulsed RF input signal has a sigma-delta ADC circuit and an AND gate for controlling delivery of clock pules to a clock input of the ADC circuit. The clock pulses are delivered to the clock input only within the duration of RF pulses of the pulsed RF input signal enabling a low speed ADC circuit to be used.

Abstract: A signal-based cable attenuation measurement device, system and methodology provides measurement of attenuation characteristics of a cable over a wide frequency spectrum. Located at a single location on a cable, a measurement device injects a signal on to the cable under measurement and receives the reflected signal, recording physical characteristics of the cable in response to the signal. A model, calibrated to estimate the effects of the cable with known impedances, evaluates the waveform generated from the cable's response to the signal and computes attenuation of the cable as a function of frequency. In some circumstances, when low signal-to-noise effects result, normally at high frequencies in long cables, the attenuation of the cable is further fitted to the model to correct the errors that occur as a result of the low signal-to-noise effects.

Abstract: An apparatus and method of determining the ratio of an amplification factor before and after changing the amplification factor of a signal normalizer that amplifies the voltage amplitude of signals input from a signal generator so that it stays within a predetermined range, and an alternating-current voltage determination device, including, reversing the phase relationship so that said sine-wave signals are negated, the output voltage amplitude of the signal generator stays within a predetermined range and the step wherein the changing the amplification factor of the signal normalizer and the output voltage amplitude of the signal generator so that they are inversely proportional and a difference is obtained between the output voltage amplitude of the signal normalizer before and after the change.

Abstract: A method and device for measuring frequency instability noise &Dgr;TRMS from a source includes measuring the signal to noise ratio SRN1 at the output from a circuit having an input to receive a frequency input signal ft, an output to supply an output signal, and a sequencing input to receive a clock signal, and determining the signal to noise ratio SRN2 at the output from the circuit, the input signal being the frequency input signal ft and the clock signal being a signal coming from the source. The frequency instability noise &Dgr;TRMS is then calculated from SRN1, SRN2 and ft.

Abstract: A method for measuring the attenuation in digital transmission lines between a switching center and a subscriber station, with a first pulse of a known frequency spectrum being sent from the switching center to the transmission line. From the multitude of the reflections received by the switching center in the time domain that pulse is selected which was caused by the total reflection at the end of the line of a certain subscriber station. The frequency spectrum of the selected pulse is determined and from the frequency spectra of the outgoing pulse and the selected received pulse, the attenuation of the transmission line is determined, depending on its frequency. To achieve the extremely high dynamics necessary for this and to obtain a pulse which is free of any overshoot, reflection measuring is carried out selectively in the frequency range and the pulse is calculated per Fourier transformation.

Abstract: A wideband precision current sensor employs DC-coupled and AC-coupled sensing circuits to generate lower and higher frequency sense signals; which are combined to form a wideband output signal that is proportional to a wideband current of interest. The frequency response of the wideband output signal is substantially flat across a wideband frequency range, 0 to 30 MHz for example, based on matching the frequency response of the DC- and AC-coupled sensing circuits. In an exemplary application, the current sensor provides feedback to a supply voltage (Vdd) amplifier used in RF envelope elimination and restoration (EER) applications.

Abstract: A thorough error suppression signal measurement system (20) having a transmitter (300) for propagating a transmission signal to a first probe 100, through a device under test (26), and into a second probe (200), and for propagating reference signals to the probes (100,200). The probes (100,200) extract normalization signals from the reference signals, exchange specific ones of the normalization signals, and combine the normalization signals with data signals derived from the transmission signal to form receiver signals. The probes (100,200) propagate the receiver signals to a receiver (400), where the signals are gain-ranged, digitized, normalized, and compensated for phase-noise.

Abstract: Attenuation of a pulsed signal traversing a cable is assessed by identifying a pulse in a signal received after traversing the cable and determining first and second reference signal levels in dependence upon characteristics of the pulse. A measurement is made of the slope of the pulse between the first and second reference signal levels (such as 25% and 75% of the peak pulse magnitude), and this measurement is used to determine an indication of the cable attenuation. The cable attenuation may in turn be used to determine a threshold for indicating loss of signal during a measurement operation.

Abstract: Apparatus and method for measuring an antenna signal strength (X). The apparatus includes a first amplifier section (3) for receiving an antenna signal and having a first automatic gain control stage; a second amplifier section (8) having a second automatic gain control stage; an automatic gain control system (12; 16′) for generating automatic gain control signals (VRF AGC, VIF AGC) for the first and second amplifier sections in accordance with a delayed automatic gain control scheme with a take-over-point. In order to measure the antenna signal strength, the take-over-point is automatically shifted towards the actual antenna signal strength.

Abstract: A method of determining the ratio of the amplification factor before and after changing the amplification factor of a signal normalizer that amplifies the voltage amplitude of signals that are input from a signal generation means so that it stays within a predetermined range and outputs that voltage amplitude by using a signal generation means, which adds two sine-wave signals of the same frequency and voltage amplitude to form the output and controls the output voltage amplitude at any phase relationship between said two sine-wave signals by a phase control means, and an alternating-current voltage determination means, includes:

Abstract: A high power radio frequency(RF) precision step attenuator includes a trim attenuator, a multi-step attenuator and a calibration/control circuit. The control circuit includes a memory for storing attenuator specific calibration data. The calibration data incorporates attenuator characteristics which are used by the control circuit to adjust the attenuator and compensate for manufacturing variances, temperature variations, and the like.

Abstract: Noise factor of a radio-frequency device under test (DUT) is determined by driving the input of the DUT with a randomly modulated sine wave and measuring the power of a resulting DUT OUTPUT signal within each of a set of equally-sized frequency bands. The noise factor is computed as a combination of the power of the modulated sine wave within each of a plurality of frequency bands and the measured power of the DUT OUTPUT signal within that same plurality of frequency bands.

Abstract: An apparatus for acquiring waveform data from a metallic transmission cable under test includes a transmitter for generating interrogating pulses for examining a segment or segment lengths of the transmission cable under test. A variable gain receiver receives a return signal from the segment or segment lengths of the cable and generates at least two gain segment acquisitions of waveform data representative of the signal from each segment or segment lengths with each gain segment acquisition of waveform data being generated with a different receiver gain. A controller operating under program control initiates the generation of interrogating pulses, establishes the receiver gain for each gain segment acquisition of waveform data, and controls the gain segment acquisitions of waveform data over the segment or segment lengths. An event table is created containing event characterization data for each gain segment.

Abstract: Robust Vibration Suppression methods and systems providing improved robustness range and are effective in single or multiple degree of freedom systems are disclosed. Methods disclosed include providing an output response from a physical system by selecting a command input to be applied to a physical system based on robustness and/or noise generation potential as determined by analyzing the acceleration frequency spectra of the command inputs. Also disclosed are specific robust command inputs and methods for deriving new robust command inputs.

Abstract: A method and apparatus which realize an RF bandpass filter having a tunable bandwidth and center frequency over a large range of the radio frequency spectrum. The filter is comprised of a cascade of filter elements. Each element is comprised of a signal splitter which simultaneously feeds a signal to a delay line and a phase shifter in a parallel path. The delayed and phase shifted signals are summed. Each filter element exhibits periodic passbands and alternating transmission zeroes. Each successive filter element has a decreased delay by an incremental factor (e.g., typically 1.2), and exhibits an increase in the frequency intervals between stopband zeroes. The bandwidth is controlled by selecting a number of "activated" ones of the successive elements. A center frequency tuning is performed by adjusting a phase shift coefficient of at least one filter element.

Abstract: A pulse-based LAN cable test instrument that processes time-domain cross-talk measurement information in order to troubleshoot and quickly locate sources of cross-talk as a function of distance along the LAN cable system is provided. A pulse-response time record between a pair of transmission lines of the LAN cable system is first acquired. A series of steps to process the time-domain pulse response data in the time record are then performed to enhance the ability of the user to locate and troubleshoot the primary contributors to NEXT along any point of the LAN cable system. The pulse response data are first normalized as a function of distance from the LAN cable test instrument in order to compensate for losses along the LAN cable. Next, the pulse response data are integrated over the time record and the absolute value of the pulse response data is calculated to more clearly show the individual sources of cross-talk within the overall LAN cable pulse response.

Abstract: A processor controlled test set for testing special service circuits of a telecommunication system. A microprocessor controls the overall operation of the test set, while a digital signal processor provides high speed timing signals to the various test circuits for generating the wave forms used in testing, as well as analyzes the test result signals that are converted into digital signals. A calibration of the test generator signals as well as the signal measuring path is carried out prior to the test sequence. The digital signal processor also provides gain control over a talking path to maintain stability thereof. An I/O circuit of the test set provides plural communication paths between remote equipment and the test set to initiate and carry out various tests. Processors in the I/O module are effective to convert the various protocols of the serial data, by way of software, to digital bit streams usable by the test set.