SIGNAL ANALYZER AND METHOD FOR PRODUCING DATE THEREFORE

• US 20100153044A1
• Filed: 11/11/2007
• Published: 06/17/2010
• Est. Priority Date: 11/24/2006
• Status: Active Grant

• Current Assignee: Tektronix Incorporated (Fortive Corp.)
• Original Assignee: Tektronix International Sales GmbH (Fortive Corp.)
• Inventors: Nara, Akira
• Granted Patent: US 8,374,812 B2
• Time in Patent Office: Days
• US Class Current: 702/76
• CPC Class Codes: G01R 13/0236 for presentation of more than one variable
• CPC Class Codes: G01R 23/165 using filters
• CPC Class Codes: G01R 23/18 with provision for recording frequency spectrum

Abstract

To produce data of an initial analysis range and a range zooming a part of it while updating them in parallel.

[Means for resolution] A first frequency analysis range and a second frequency analysis range that is narrower than the first one are set with an operation panel 34, etc. A first signal path 171 produces first time domain data of a frequency converted signal under test according to a first data production rate that is set depending on the first frequency analysis range. A second signal path 172 produces second time domain data of frequency converted signal under test according to a second data production rate that is set depending on the second frequency analysis range and is slower than the first data production rate. A CPU receives the first and second time domain data in parallel and produces first and second frequency domain data by fast Fourier transform wherein frequency shift amounts in the frequency conversions in the first and second signal path are different depending on a difference between the center frequencies of the first and second frequency analysis ranges.

Claims

1. A signal analyzer comprising:

an analysis range setting means for setting a first frequency analysis range and a second frequency analysis range that is narrower than the first frequency analysis range;

a first signal path to which first data production rate and first data acquisition time are set according to the first frequency analysis range for producing first time domain data of a frequency converted signal under test;

a second signal path to which a second data production rate that is slower than the first data production rate is set according to the second frequency analysis range for producing second time domain data of a frequency converted signal under test; and

a calculation means receiving the first and second time domain data for producing first and second frequency domain data in calculation.

2. The signal analyzer as recited in claim 1 wherein frequency shift amounts of the frequency conversions in the first and second signal paths are different according to a difference between the center frequencies of the first and second frequency analysis ranges.

3. The signal analyzer as recited in claim 1 or 2 wherein a second data acquisition time that is longer than the first data acquisition time is set to the second signal path.

4. The signal analyzer as recited in claim 1, 2 or 3 wherein the first signal path has a delay means for compensating a difference between the data production speeds of the first and second time domain data depending on a difference between the first and second data production rates.

5. The signal analyzer as recited in claim 1, 2, 3 or 4 wherein the analysis range setting means sets a first time analysis range and a second time analysis range that is narrower than the first time analysis range,

the first signal path produces a first time domain data of the signal under test according to a first data production rate that is set according to the set first time analysis range, and

the second signal path produces second time domain data of the signal under test according to a second data production rate that is faster than the first data production rate and is set depending on the second time analysis range wherein the second signal path has a delay means for compensating a difference between data production speeds of the first and second time domain data according to a difference between the first and second data production rates.

6. A data production method for a signal analyzer comprising steps of:

setting a first data production rate and a first data acquisition time according to a set first frequency analysis range, producing first time domain data of a frequency converted signal under test and producing first frequency domain data from the first time domain data; and

setting a second data production rate that is slower than the first data production rate when the second frequency analysis range that is narrower than the first frequency analysis range is set, producing second time domain data of a frequency converted signal under test and producing second frequency domain data from the second time domain data wherein the first and second frequency domain data are updated in parallel according to input of the signal under test.

7. The data production method for a signal analyzer as recited in claim 6 wherein a second data acquisition time that is longer than the first data acquisition time is set when the second frequency analysis range that is narrower than the first frequency analysis range is set to make frequency resolution of the second frequency domain data higher than frequency resolution of the first frequency domain data.

8. A data production method for a signal analyzer comprising steps of:

setting a first data production rate according to a set first time analysis range to produce first time domain data from a signal under test; and

setting a second data production rate that is faster than the first data production rate when a second time analysis range that is narrower than the first time analysis range is set to produce second time domain data from the signal under test wherein the first and second time domain data are updated in parallel according to input of the signal under test.