Abstract: A power spectrum waveform is obtained by logarithmically amplifying a signal received by a frequency-sweep operation, detecting the amplified output of each frequency sweep, converting the detected output into a digital signal value in decibels, and converting this digital signal value into an antilogarithmic power value in watts for each display point within the width of the frequency sweep. Upon completion of the frequency sweep operation, the power values which have been converted into antilogarithmic values for each frequency sweep are averaged for each display point, the average power values are converted into logarithmic values, and the logarithmic values are displayed as a spectrum display.

Abstract: A spectrum analyzer in which automatic setting of parameters such as band width is done by the analyzer without manual operator input and noise measurements are determined and displayed to the operator. This is accomplished by an input signal being supplied to a frequency mixer via an input variable attenuator. The frequency of the input signal is mixed with the frequency of a local signal from a frequency sweep generator. The mixed signal is then supplied to a band pass filter and the output of the filter is amplified by an amplifier. The frequency of the amplified output is mixed with the frequency of a local signal from a local oscillator by a frequency mixer. The intermediate frequency signal is taken out by a band pass filter and the output is detected by a detector. The detected output is converted into a digital signal by an A/D converter after passing through a low pass filter and the digital signal is stored in a buffer memory. A CPU sets an attenuation amount.

Abstract: A measuring device and method use a spectrum analyzer. The spectrum analyzer comprises a display screen controlled by a processor on which a spectrum of an input signal is displayed in a frequency region on a half portion of the display screen and a noise level at a frequency associated with the input signal is displayed in a time region on another half portion of the display screen.

Abstract: A spectrum analyzer converts frequencies of an input signal using a local signal from a local signal generator, detects the frequency converted outputs, and sweeps the frequencies of said local signal generated by said local signal generator, to obtain a frequency-based output, wherein said local signal generator comprises a digital direct synthesizer for incrementing the output frequency for every input clock, a variable frequency oscillator for outputting an oscillation output as said local signal and a phase locked loop for controlling the oscillation frequency of said variable frequency oscillator using the output of said digital direct synthesizer as a reference signal.