Signal generator for digital spectrum analyzer
AssigneeTakeda Riken Co., Ltd.
InventorHitoshi Kitayoshi
Life of this patent
Estimating the term…
Abstract
A signal generator generates a test signal for input to a device under test the output signal of which is subjected to fast Fourier transform analysis by a fast Fourier transformer. A waveform memory is read out in synchronism with data input to the fast Fourier transformer. The waveform memory has stored therein sample values of a composite waveform of a plurality of predetermined spectra. The output read out from the waveform memory is converted by a D/A converter into an analog signal for use as the test signal.
Claims14
A signal generator for a digital spectrum analyzer in which a test signal from the signal generator is supplied to a device under test and a signal therefrom is sampled and input into a fast Fourier transform analyzer for analysis, comprising:
- clock generating means for generating a clock signal synchronized with the input of the sampled signal into the fast Fourier transform analyzer;
- an address counter for counting the clock signal generated by the clock generating means and providing a corresponding count value;
- a waveform memory connected to the address counter and read out with said count value used as an address, the waveform memory having stored therein, as a digital value, the amplitude value at each of equally spaced points of a composite waveform of a plurality of predetermined spectra divided in the time-axis direction by an integral multiple of the number of sample points necessary for one analysis by the fast Fourier transform analyzer;
- and
- a D/A converter connected to the output side of the waveform memory, for converting the output read out therefrom into an analog signal for output as the test signal.
Dependencies are inferred from the claim text.