Internal chirp generator with time aligned acquisition in a mixed-domain oscilloscope

Patent metadata

Field	Value
Publication number	US-2016103154-A1
Application number	US-201514974298-A
Country	US
Kind code	A1
Filing date	Dec 18, 2015
Priority date	Oct 23, 2012
Publication date	Apr 14, 2016
Grant date	—

Abstract

A mixed-domain oscilloscope (MDO) includes a signal generator configured to generate a test signal having a span ranging from a user-configurable start frequency to a user configurable stop frequency, an output channel coupled to the signal generator and configured to transmit the test signal, an RF input channel configured to receive a return signal based on the test signal, an acquisition section configured to acquire and digitize the return signal as an acquisition record, and a ramp busy signal generator configured to substantially time-align the acquisition record with the test signal. The test signal includes a chirp signal that is a linearly swept sine wave that spans between the user-configurable start frequency and the user-configurable stop frequency. Methods include calibrating the chirp signal, connecting the MDO in various test configurations relative to external return loss bridge and DUT equipment, and performing measurements such as S21 (db), S11 (db), and distance-to-fault type measurements.

First claim

What is claimed is:

1 . A method for measuring a scalar s parameter on a mixed-domain oscilloscope, the method comprising:
generating, by a signal generator, a test signal having a span ranging from a user-configurable start frequency to a user configurable stop frequency; transmitting, by an output channel, the test signal; receiving, by an RF input channel, a return signal that is based on the test signal; acquiring and digitizing the return signal as an acquisition record; time aligning the acquisition record with the test signal; processing an entire spectrum of frequencies associated with the acquisition record at substantially the same time; and displaying, on a display of the mixed-domain oscilloscope, the spectrum so as to measure the scalar s parameter.

2 . The method of claim 11 , wherein the scalar s parameter is a S21 scalar s parameter, the method further comprising:
connecting a first port of a device under test to the output channel of the mixed-domain oscilloscope; connecting a second port of the device under test to the RF input channel of the mixed-domain oscilloscope; and displaying, on the display of the mixed-domain oscilloscope, the spectrum so as to measure the S21 scalar s parameter.

3 . The method of claim 11 , wherein the scalar s parameter is a S11 scalar s parameter, the method further comprising:
connecting the output channel of the mixed-domain oscilloscope to a first port of a return loss bridge; connecting the RF input channel of the mixed-domain oscilloscope to a second port of the return loss bridge; connecting a first port of a device under test to a third port of the return loss bridge; terminating a second port of the device under test; and displaying, on the display of the mixed-domain oscilloscope, the spectrum so as to measure the S11 scalar s parameter.

4 . The method of claim 11 , further comprising calibrating the test signal.

5 . The method of claim 14 , wherein calibrating the test signal further comprises:
looping the test signal from the output channel to the RF input channel; displaying, on the display of the mixed-domain oscilloscope, a horizontal reference line associated with the return signal; detecting ripples in the reference line; calibrating out the ripples in the reference line so that the reference line represents a 100% reflection reference line.

6 . The method of claim 11 , further comprising:
selecting a resolution bandwidth to be within the span of the test signal.

7 . The method of claim 1 , wherein:
the test signal is a chirp signal; the signal generator is configured to generate the chirp signal; the return signal received by the RF input channel is based on the chirp signal; and the acquisition record is acquired and digitized by an acquisition section configured to acquire, in a single acquisition, substantially the entire chirp signal.

8 . The method of claim 7 , wherein the chirp signal is a linearly swept sine wave configured to span between the user-configurable start frequency and the user-configurable stop frequency.

Assignees

• Tektronix Inc

Inventors

• Dalebroux Donald J

Classifications

• G01R13/0245 Primary

  for inserting reference markers · CPC title

• G01R13/0272

  for sampling · CPC title

• G01R31/2837 Primary

  Characterising or performance testing, e.g. of frequency response (transient response G01R27/28) · CPC title

• G01R27/04

  in circuits having distributed constants {, e.g. having very long conductors or involving high frequencies} · CPC title

• G01R13/0236

  for presentation of more than one variable · CPC title