Anritsu Corporation

Anritsu Electric Co., Ltd.

Mitsuyoshi Takano

Aiichi Katayama

Mamoru Ando

Hiroyoshi Oka

Seiryo Fukaya

Takehiko Kawauchi

Katsuhisa Iiyoshi

Yoshifumi Imazu

Kenichi Kon

Takahiro Wada

Narushi Amamoto

Katsuhiko Kamiyama

A measurement unit U100 measures an input signal to be measured by sweeping frequencies in a measurement range having a predetermined frequency band so as to obtain waveform data to be developed on the frequency axis such as spectrum data in, e.g., a spectrum analyzer. The waveform data obtained by the measurement of the measurement unit U100 is displayed by a display device 500 via a display data processor U20 included in a control unit U200 to be developed on the frequency axis of the display device, i.e., in correspondence with the measurement frequencies. The control unit U200 includes a measurement controller U30 for controlling the measurement unit U100 so as to display waveform data obtained by enlarging or reducing waveform data, before a measurement frequency condition is changed, at a predetermined magnification to have a predetermined point on the frequency axis as the center on the basis of a change in measurement frequency condition set by a condition setting unit U900, and an enlargement display/stable display processor U40 for controlling the display data processor U20. The enlargement display/stable display processor U40 realizes high-definition waveform observation, and has a function of controlling the display device U500 as the control unit U200.

Waveform display apparatus of frequency sweep type for facilitating

A measurement unit U100 measures an input signal to be measured by sweeping frequencies in a measurement range having a predetermined frequency band so as to obtain waveform data to be developed on the frequency axis such as spectrum data in, e.g., a spectrum analyzer. The waveform data obtained by the measurement of the measurement unit U100 is displayed by a display device 500 via a display data processor U20 included in a control unit U200 to be described later to be developed on the frequency axis of the display device, i.e., in correspondence with the measurement frequencies. The control unit U200 includes a measurement controller U30 for controlling the measurement unit U100 so as to display waveform data obtained by enlarging or reducing waveform data, before a measurement frequency condition is changed, at a predetermined magnification to have a predetermined point on the frequency axis as the center on the basis of a change in measurement frequency condition set by a condition setting unit U900, and an enlargement display/stable display processor U40 for controlling the display data processor U20. The enlargement display/stable display processor U40 realizes high-definition waveform observation as the gist of this invention, and substantially has a function of controlling the display device U500 as the control unit U200.

Waveform display apparatus for easily realizing high-definition waveform

A spectrum analyzer comprising various components. In the analyzer, a high-frequency signal processing circuit frequency-converts an object signal including waves recurring for a short period of time, into an intermediate-frequency signal, by using a local oscillation signal swept continuously over a desired range of frequencies, and thereby outputs a frequency spectrum of the object signal. A demodulator demodulates the frequency spectrum output by the high-frequency signal processing circuit. A selection signal supplying section supplies a selection signal for selecting that portion of the spectrum output by the demodulator, which lies waves to be analyzed. A control section outputs said portion of the spectrum output by the demodulator, in accordance with the selection signal output from the selection signal supplying section. A display displays the frequency spectrum output by the control section. A sweep control section causes the high-frequency signal processing circuit to sweep the local oscillation signal repeatedly, each time for a period which is not an integral multiple of the cycle period of the selection signal.

Spectrum analyzer capable of displaying signals obtained during a

A frequency conversion section sweeps an object signal within a desired measurement frequency range, thereby frequency-converting the object signal. A peak detector detects a peak of an output from the frequency converting section. A measurement detector measures and detects the output from the frequency conversion section simultaneously with the peak detection by the peak detector. The measurement detector has an output characteristic lower than an output characteristic of the peak detector. A display displays an output from the peak detector and an output from the measurement detector on a single display screen, in synchronism with the sweeping by the frequency conversion section, with these outputs of the peak detector and the measurement detector being plotted along an axis representative of frequencies. In another mode of the invention, an alarm device indicates the fact that an output from the peak detector has exceeded a predetermined allowable limit level.

Spectrum analyzer having functions for simultaneously executing plural

An input processing section outputs a digital signal corresponding to a frequency sweep range of an input signal. A memory stores the digital signal. A display displays the digital signal stored in the memory as an image which is developed along a frequency axis. A scroll command section provides a command for shifting the image. A controller supplies, prior to the command, control signals to the input processing section, for causing the input processing section to process the input signal in a first frequency sweep range and supplies, and to the memory, for causing the memory to store the digital signal. When the command is received, the controller supplies control signals to the input processing section for causing the input signal to be processed in a second frequency sweep range in accordance with a content of the command, and to the memory for causing an address range of the memory to shift and the memory to store the obtained digital signal. The display displays an image of the second frequency sweep range continuously with the image of the first frequency sweep range which is shifted in accordance with the command.

Signal analyzer having partially scrolling function for display screen

A frequency converter converts an input signal into an intermediate frequency signal corresponding to a local oscillation signal to be analog-swept from a local oscillator. An A/D converter converts the intermediate frequency signal into the corresponding digital signal. A memory stores the digital signal in accordance with its a frequency. A display displays the digital signal stored in the memory along a frequency axis. A sweep signal generator receives first or second sweep measurement frequency range setting data from a sweep range setting unit and supplies the data to the local oscillator as the analog sweep signal for an entire or partial sweep operation. Upon reception of the first sweep measurement frequency range setting data, a display controller causes the display to display the digital signal stored in the memory in correspondence with the analog sweep signal for the entire sweep operation. Upon reception of the second sweep measurement frequency range setting data present in the first range from the sweep range setting unit, the display controller causes the display to update and display the digital signal of a portion corresponding to the second sweep measurement frequency range which is updated in the memory in correspondence with the analog sweep signal for the partial sweep operation.

Signal analyzer apparatus with analog partial sweep function

In a siganl analyzer apparatus, a signal received while a local oscillator is swept in a analog manner is selected and detected by an IF circuit using a desired RBW, and the resultant data is stored in a memory and displayed on a display unit. A sweep signal generator controls the local oscillator in an analog manner such that frequency measurement can be performed within a desired measuring frequency range. A peak search section outputs a frequency valve corresponding to the maximum value of the data in the memory. A discriminator compares the span set in the sweep signal generator with the resolution bandwidth set in the IF circuit, when a frequency is measured using the desired span, and outputs the obtained value. A frequency controller causes the sweep signal generator to perform sweeping/measurement by setting a frequency detected by the peak search as a center frequency, and by using a span narrower than that used in the previous measurement cycle, on the basis of the comparison result from the discriminator. A frequency measuring section measures the frequency of an input signal using the output frequencies from the local oscillator and the IF circuit, on the basis of the comparison result from the discriminator, when the frequency controller causes the sweep signal generator to perform frequency measurement by minimizing the span.

Signal analyzer apparatus with automatic frequency measuring function

An input section outputs a digital signal representing a characteristic value corresponding to a measurement range of an input signal. The digital signal is then stored in a memory. A display displays the digital signal stored in the memory as an image which is developed along one of two-dimensional coordinates axes and represents the predetermined characteristic value. A zone setting section outputs zone width data for setting, as a marker zone, a portion including a desired range of the one axis for the image displayed on the display. A zone display controller causes the display to display the marker zone, in accordance with the zone width data. A detector reads out the digital signal within the desired range of the one axis, from the memory, in accordance with the zone width data, and detects the specific characteristic value in the readout digital signal. A display controller causes a display to display detected specific characteristic value data.

Waveform measuring apparatus with marker zone displaying function

A spectrum analyzer having an automatic attenuator setting function, actuatable to automatically set the degree of attenuation provided by an input attenuator to an optimum value in accordance with the peak level of the frequency span of a signal under measurement, i.e. to a minimum attenuation value consistent with the prevention of generation of spurious signal components through distortion within the spectrum analyzer, e.g. harmonic frequency distortion within the mixer of the spectrum analyzer. Low-level frequency components can thereby be observed without the presence of spurious components on the spectrum analyzer display, with no need for manual input attenuator adjustment. A compensating degree of I.F. amplification is automatically provided to match the attenuation setting.

Spectrum analyzer

A spectrum analyzer is provided with means for setting the level of an input signal applied to the mixer of the frequency converter circuit in the spectrum analyzer to an optimum level, i.e., such that the relative amounts of harmonic distortion and average noise in the displayed spectrum are balanced, the input level setting being established on the basis of the current reference level and resolution bandwidth settings.

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Tokyo, Japan

Mitsuyoshi Takano