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Testing Waveform Parameters

IP.com Disclosure Number: IPCOM000085681D
Original Publication Date: 1976-May-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 4 page(s) / 102K

Publishing Venue

IBM

Related People

Foreman, SH: AUTHOR [+3]

Abstract

Waveform analysis of complex parameters is accomplished via sequentially storing incremental data taken from a device under test (DUT) and using programmed arithmetic operations to find the required test parameters.

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Testing Waveform Parameters

Waveform analysis of complex parameters is accomplished via sequentially storing incremental data taken from a device under test (DUT) and using programmed arithmetic operations to find the required test parameters.

In reference to the flow diagram of Fig. 1, frequency synthesizer 2 is sequentially incremented via part number program instructions 1 which include increment size, amplitude, and start/stop frequencies. A gain/phase meter 3 reads the DUT gain at each applied input frequency increment. Computer program 4 scales the reading to an appropriate unit of measure and converts the binary data to a floating-point number. Each incremental gain reading is then stored in a temporary (TEMP) storage location controlled by the part number program.

In the outlined example, gain-vs-frequency is incrementally plotted and will be used as an example, although any voltage-vs-time or time-vs-voltage parameter can be tested in a similar manner.

Arithmetic operations under part number program control, scan data stored in TEMP locations of Fig. 4 and together with a table of constants, compute parameters and check results to test limits. Arithmetic operations are programmed by the part number programmer in engineering language statements, with intermediate results stored in specified TEMP locations.

For example, tests can be performed on a ba pass filter. In reference to Fig. 2, the frequency is incremented from a start frequency to a stop frequency in linear increments with gain being measured and stored at each incremental frequency point. A typical bandpass filter response is shown in Fig. 2 where 10 is the "fc" or high point, 8 is the low point, and 11 is a computed F1;F2 ratio value. The readings stored in TEMP are scanned for the F1;F2 ratio values closest to the computed F1;F2 ratio.

Fig. 2 shows a defective bandpass filter with multiple F1;F2 ratio points.

The steps required in analyzing the incremental gain data stored in TEMP and computing the necessary filter parameters are described as follows. A. "Low" is found at point 8. Its re...