Abstract: A signal analyzer has an analysis scale and a display scale that are independently selectable. The signal analyzer receives a first representation of an applied signal and provides from the first representation at least two alternative representations. A first selective input enables a designated one of the alternative representations to be applied to a filter to reduce variance of the designated representation. The signal analyzer then converts the received one of the alternative representations having reduced variance to at least two alternative display scales. A second selective input enables a designated one of the alternative display scales to be displayed on a monitor, display screen or other output device of the measurement instrument or system.

Abstract: Absolute delay of a FTD is characterized by applying a stimulus signal to a first port of the FTD. A second port of the FTD is coupled to a delay element having a known delay and a reflective termination. A drive signal is applied to a third port of the FTD. A time domain reflection response to the stimulus signal is obtained and a signal peak within the response that corresponds to a return signal from the reflective termination is identified. Absolute delay of the frequency translation device is then extracted based on the known delay of the delay element and a time that corresponds to the occurrence of the identified signal peak. Delay versus frequency is characterized by isolating a segment of the obtained time domain reflection response that corresponds to a return signal from the reflective termination. Inverse frequency transforming the isolated segment of the time domain reflection response provides delay characteristics of the FTD versus frequency.

Abstract: A method for automatically setting a reference level is provided. A frequency-converted output of frequency converter 13 is branched and the branched output is further frequency-converted by another frequency converter 33. The thus frequency-converted signal is converted to a digital signal by an AD converter 31 and the digital signal is once stored in a memory 35. The digital data is read out from the memory 35 and a check is made to see if the AD converter 31 was overflown. If the AD converter 31 was overflown, an attenuation amount of a first stage attenuator 12 is increased from an initially set value to acquire a data again. If the AD converter 31 was not overflown, a check is made to see if a peak value of the digital data is within a range of 85%-65% of the full scale of the AD converter 31. If a peak value of the digital data is not within the range of 85%-65% of the full scale, a calculation is performed to increase/decrease the gain of an amplifier 15.

Abstract: A wide band signal analyzer includes a frequency converter for converting a signal under test to an intermediate frequency signal. A narrow band signal processor receives the intermediate frequency signal and produces a first digital signal representing a first frequency band of the intermediate frequency signal and a wide band signal processor receives the intermediate frequency signal and produces a second digital signal representing a second frequency band of the intermediate frequency signal. A transfer rate decelerator decelerates the transfer rate of the second digital signal, and a digital processor processes selectively the first digital signal or the output signal of the transfer rate decelerator. A memory stores the processed output of the digital processor.

Abstract: The present invention provides a wide band IQ splitting apparatus suitable for using in a spectrum analyzer. A quadrature oscillator 30 generates a pair of quadrature signals. An amplitude and phase adjuster 32 receives the quadrature signals and adjusts the balances of the amplitude and the phase between them. An analog splitter 20 mixes an analog IF signal with the pair of quadrature signals for splitting the analog IF signal into analog I and Q signals. First and second analog to digital converters 22 and 24 convert the analog I and Q signals into digital I and Q signals, respectively. A control and processing circuit detects the imbalances of the amplitude and phase between the digital I and Q signals for controlling the amplitude and phase adjuster 32. The amplitude and phase adjuster 32 is previously calibrated. For this first calibration, the analog splitter 20 receives a first calibration signal instead of the analog IF signal.

Abstract: Techniques for use in sweep synchronization test equipment include receiving a simulation setting and displaying a simulated result based on the simulation setting and previously-measured data. The equipment is switched to a measurement mode in response to user activity, and the simulation setting is used as a control setting. A new measurement is performed based on the control setting. The displayed simulated result is updated based on data obtained from the new measurement.

Abstract: A mode selection method for signal analyzers having alternative swept and Fast Fourier Transform (FFT) modes of operation enables tradeoffs between measurement speed and dynamic range to be optimized in selecting between the alternative operating modes. The method includes setting the signal analyzer to either a manual state or an automatic state according to a first input to a user interface. When the manual state is set, the analyzer is operated in either the swept operating mode or the FFT operating mode according to a second input to the user interface. When the automatic measurement state is set, a third input to the user interface determines whether measurement speed or dynamic range is optimized. Measurement speed is optimized according to a first optimization scheme and dynamic range is optimized according to a second optimization scheme.

Abstract: To measure phase noise of an output signal of a test specimen with a spectrum analyzer whose measuring branch comprises a plurality of serially-connected heterodyne stages, a compensation generator is provided which comprises a plurality of heterodyne stages arranged serially-connected in reverse order to that of the heterodyne stages of the measuring branch and which has an input oscillator which corresponds to a last intermediate frequency of the measuring branch; the output signal of this compensation generator being added to an output signal of the test specimen, having an approximate equal-value level and being approximately oppositely phased thereto, in an adder stage which is connected serially to the measuring branch.

Abstract: A method of measuring non-coherent electrical signals using either windowed or non-windowed digital signal processing. The method includes the steps of providing a digitized version of the non-coherent electrical signal; generating a matrix A of correlations between sine and cosine components of known correlation frequencies and sine and cosine components of signal frequencies; generating an inverse matrix A−1 of the correlation matrix; generating a second matrix B of correlations between sine and cosine components of the correlation frequencies and the digitized non-coherent electrical signal; and generation of a third matrix C which represents the measured amplitudes of the sine and cosine components of the non-coherent electrical signal.

Abstract: A method for determining the harmonic phase response ∠POx of a device under test (DUT) is performed on a vector network analyzer (VNA). The phase ∠GN1 of the transfer response GN1 of the DUT at the fundamental frequency is determined from VNA measurements after appropriate normalization. The corrected phase ∠GHxC of the harmonic transfer response of the DUT is determined from VNA measurements after appropriate normalization. The corrected phase ∠GHxC of the harmonic transfer coefficient GHx is subtracted from a predetermined phase reference ∠refx to obtain a difference ∠refx−∠GHxC, and the phase ∠GN1 of the transfer coefficient GN1 at the fundamental frequency is added to the difference ∠refx−∠GHxC to obtain the harmonic phase offset ∠POx. For the second and third harmonics using a clipping waveform, the phase reference ∠refx is 180°.

Abstract: An exemplary embodiment of the present invention is an apparatus for receiving sweep testing signals and generating frequency response values therefrom. The apparatus includes a test input, a controller, a receiver circuit and a measurement circuit. The test input has a first connection arrangement for connecting to a test output of the sweep transmitter and also has a second connection arrangement for connecting to a terminal of the communication system to be tested. The controller is operable to generate a sweep control signal responsive to a sweep plan. The receiver circuit has a control input connected to receive the sweep control signal from the controller, and is operable to tune to a plurality of frequencies responsive to the sweep control signal. The measurement circuit is coupled to the receiver circuit and is operable to generate measurement signals corresponding to the plurality of frequencies.

Abstract: There are provided a frequency analysis method permitting a frequency analysis to be performed at a high rate and a sweep type spectrum analyzer using such frequency analysis method.

Abstract: The present invention relates to electronic calibration equipment for verifying the high frequency characteristics of electronic test equipment, including oscilloscopes and time interval analyzers.

Abstract: A spectrum analyzer is provided with a continuous period measurement function which continuously measures time periods of each and every cycle of an IF signal to analyze changes in frequency and time period of an input signal in a time domain. The frequency spectrum analyzer having a sweep local oscillator includes a continuous period measurement block for continuously measuring each time period of an IF signal produced by mixing the input signal and the local oscillator signal, and a processor and display for processing the data representing the continuous time period produced by the continuous period measurement block to analyze the input signal in the time domain.

Abstract: For determination of the transmission function of a measurement apparatus, in particular of a spectrum analyzer, a calibration signal, modulated with a modulation signed such that a line spectrum arises within the frequency band of interest is provided in the measurement apparatus. In a computer, the modulation signal is calculated from the digitized output signal of the measurement apparatus. The desired transmission function is then calculated therefrom according to magnitude and phase.

Abstract: An apparatus and method of detecting, tracking and displaying lightning activity is disclosed. A lightning stroke has associated therewith electric and magnetic field components characterized by maximum rise times and minimum power levels. The field signals comprise a plurality of sub pulses also. An electric field antenna and a pair of magnetic field antennas are disposed to receive the field components associated with lightning activity. Control circuitry cooperating with rise time and threshold measuring which operates on the field signals received by antennas generates control signals including integration and sampling control signals over a predetermined time interval (preferable one point four seconds) and for sampling and holding the field signals at each of the sub pulse peak. Preprocessing circuitry upon command from a programmable microprocessor A to D converts the sampled field components where they are stored as digital data in memories.

Abstract: A time-domain baseband measurement method measures modulated microwave signals typically used in communication systems by converting microwave signals to baseband before measurement for improved accuracy compared to direct measurement at the microwave frequency. A downconverting receiver is first characterized using a prior characterization method and then the modulated microwave signal is applied to the downconverting receiver and the response of the downconverting receiver is removed to provide an accurate characterization of the modulated microwave signal. Such an accurate measurement of the modulated microwave signal can be used for communications system performance verification as well as for characterizing communications devices and systems. One particular application is the measurement of input/output characteristics of nonlinear power amplifiers using such modulated microwave signals.

Abstract: Frequencies fx between the measurement harmonic (mth-degree harmonic) and the (m±1)th-degree harmonics are determined from an expression of fx=(fs*m)±{(fs/n)*k)} where n and k are each an integer. Currents of inter-harmonics of the frequencies fx above and below the measurement harmonic are injected into an inject point in a power system in n cycles of the fundamental wave. Voltage at the inject point based on the injected currents and currents at least either upstream or downstream from the inject point are measured. Admittances for the inter-harmonics above and below the measurement harmonic on at least either the upstream or downstream side from the harmonic inject point are calculated from the measurement results. Interpolation processing based on the calculation results is performed, thereby finding and determining an admittance for the measurement harmonic.

Abstract: A plasma processing system controls the electronegativity of a plasma produced by ionizing a process gas when processing a substrate by using the plasma. The relation between the pressure in a processing vessel (1) and the frequency of a RF power source (11′), and the electronegativity of the plasma produced by the agency of RF power is determined beforehand. A controller (18) adjusts the pressure in the processing vessel (1) and/or the frequency of the RF power source (11′) in a real-time control mode by a feedback control operation on the basis of a pressure measured by a pressure sensor (17) and a frequency measured by a frequency meter (15) to adjust the electronegativity of the plasma to an appropriate value. The electronegativity of the plasma can be determined through simulation using a one-dimensional RCT model of the plasma.