Triggered narrow-band method for making pulsed-rf networking measurements

Abstract

A method of measuring a device under test (“DUT”) includes applying a pulsed-RF input signal to the DUT and coupling an output of the DUT to a receiver having an output bandwidth selected to measure a center tone in an RF pulse response spectrum from the output of the DUT. The receiver is triggered so as to sample data output from the DUT during a window period, and stops taking data after the window period.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS [0002] Not applicable. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0003] Not applicable. REFERENCE TO MICROFICHE APPENDIX [0004] Not applicable. BACKGROUND OF THE INVENTION [0005] Many microwave electronic systems operate in a pulsed-RF mode. Radar systems and time-division multiple access (“TDMA”) wireless communications systems are examples of systems that operate in a pulsed-RF mode. Radar systems typically operate with signals in the range of several gigahertz (“GHz”) to tens of GHz and use devices such as antennas, amplifiers, transmit-receive modules, and frequency converters (“mixers”). TDMA wireless communication systems typically operate below about 6 GHz, and use similar electronic devices as are used in radar systems. However, most electronic devices are tested under continuous wave (“CW”) conditions. That is, the electronic device that is being tested, which is commonly called a “device under test” or “D...

AI Technical Summary

Problems solved by technology

In other instances, a CW signal might destroy the DUT.

For example, performing a CW wafer test (i.e. on DUTs that have not been separated from the wafer on which they were fabricated) might destroy a DUT that is not adequately heat sunk.

Other DUTs might not be designed to operate in a CW mode, such as high-power amplifiers used in radar systems.

The minimum RF pulse duration measurable using this technique is limited by the maximum bandwidth of the receiver being used.

Wide-band pulsed-RF measurements are desirable because the dynamic range is independent of duty cycle; however, the dynamic range is limited by the wide IF bandwidth.

If a significant amount of energy is outside of the bandwidth of the receiver, the receiver cannot accurately represent and measure the RF pulse response of the DUT.

Narrow-band RF pulse detection is used when enough of the RF pulse spectrum is outside the bandwidth of the receiver so that wideband detection cannot be used.

Unfortunately, the dynamic range of the measurement is a function of duty cycle.

Thus, as the duty cycle of the RF pulses decreases (i.e. longer time between RF pulses), the average power of the RF pulses gets smaller, which degrades the signal-to-noise ratio.

Images