Patent ID: 8155904

Claim:
A method of measuring vector-signal relationships over a wide bandwidth at high frequencies, said method comprising: producing a low-frequency data signal from a synchronized digital-to-analog converter; producing a high-frequency local-oscillator signal; up-converting said low-frequency data signal to a high-frequency data signal by mixing with the high-frequency local-oscillator signal; passing the desired up-converted sideband signal using a variable filter; conveying said high-frequency data signal to a Device Under Test; conveying the reflected and/or the through high-frequency data signals from the Device Under Test and/or the incident data signals to multiple receivers; passing the desired high-frequency data signal to a variable filter in each receiver; down-converting said high-frequency filtered data signal to a low-frequency data signal by mixing with the high-frequency local-oscillator signal in each receiver; up-converting and down-converting all data signals using a common local oscillator; switching base-band filters in each receiver to independently select offset frequency bands; digitizing low-frequency signals with analog to digital converters that are synchronized with a common high-speed clock; measuring a reference data signal at a fixed frequency in one receiver at time 1; measuring a data signal at an offset frequency in a second receiver at time 1; measuring a reference data signal at a fixed frequency in one receiver at time 2; measuring a data signal at a new offset frequency in a second receiver at time 2; and continuing the measurement of reference and offset frequency signals for n times in order to build up a wideband signal.