Signal measurement systems and methods

Abstract

Signal measuring systems, and measurement methods are disclosed.

1 . A measurement system for conducting measurements on a device-under-test (DUT), wherein impedance is controlled or varied over a set of measurement conditions and a parameter or set of parameters measured for each measurement condition, the system comprising:
 a passive impedance controlling tuner;   a signal coupling device connected between a signal port of the DUT and the tuner for sampling signals propagating between the passive impedance controlling tuner and the DUT;   measurement equipment for receiving response signals from the signal coupler; and   wherein the measurement system is free of active impedance controlling devices which employ signal injection to synthesize an impedance.   
   
   
       2 . The system of  claim 1 , wherein the signal coupling device is mounted in a fixed position relative to the DUT. 
   
   
       3 . The system of  claim 1  wherein the signal coupling device is a separate device relative to the passive impedance controlling tuner. 
   
   
       4 . The system of  claim 1 , wherein the signal coupling device is integrated with the passive impedance controlling tuner. 
   
   
       5 . The system of  claim 1 , wherein the DUT is selected from the group comprising power transistors, power FETs or other power amplifying devices, small-signal low noise transistors, amplifying devices, frequency translating devices, frequency multipliers, two-terminal devices, three-terminal devices, and mixers. 
   
   
       6 . The system of  claim 1 , wherein the passive impedance controlling tuner is selected from the group consisting of slide-screw tuners, double slug tuners, stub tuners and solid state tuners. 
   
   
       7 . The system of  claim 1 , wherein the passive impedance controlling tuner is manually controlled. 
   
   
       8 . The system of  claim 1 , wherein the passive impedance controlling tuner is automated with computer control. 
   
   
       9 . The system of  claim 1 , wherein the signal coupling device is selected from the group consisting of a directional coupler, a directional bridge, a voltage-current probe, or a directional current probe. 
   
   
       10 . The system of  claim 1 , wherein the measurement equipment further provides excitation signals to the said passive impedance controlling tuner. 
   
   
       11 . The system of  claim 1 , wherein the signal coupling device is adapted to allow measurement of phases and amplitudes of said sampled signals. 
   
   
       12 - 28 . (canceled) 
   
   
       29 . A method for using a measurement system including an impedance-controlling tuner, comprising a sequence of the following steps:
 pre-characterizing the tuner over some desired tuning range at a number of pre-characterized calibrated impedance tuning points;   connecting a signal coupling device in the measurement system to allow measurement of an impedance presented to a device-under-test (DUT) with the DUT in place;   for DUT measurements, setting the impedance tuning at one of said pre-characterized calibrated impedance tuning points or by interpolating between pre-calibrated impedance tuning points to achieve a particular target impedance presented to the DUT; and   measuring an actual impedance presented to the DUT after the tuning setting is determined and set.   
   
   
       30 . The method of  claim 29 , further comprising:
 setting the tuner to a new tuner impedance determined by an offset between the target impedance and the measured actual impedance;   measuring an actual impedance presented to the DUT at the new tuner impedance setting.   
   
   
       31 . The method of  claim 29 , wherein said connecting the signal coupling device comprises:
 connecting the signal coupling device between the DUT and the tuner.   
   
   
       32 . A method for conducting measurements of a device-under-test (DUT) in a measurement system including an impedance tuning mechanism for presenting a variable impedance to the DUT, comprising a sequence of the following steps:
 pre-characterizing the tuning mechanism over a desired tuning range at a number of pre-characterized calibrated impedance tuning points;   connecting the pre-characterized tuning mechanism into the measurement system with a signal coupling device between the DUT and the tuning mechanism;   determining a tuning setting for the tuning mechanism to achieve a particular target impedance presented to the DUT at one of said pre-characterized calibrated impedance tuning points or by interpolating between the pre-characterized impedance tuning points;   setting the tuning mechanism to the tuning setting;   measuring an actual impedance presented to the DUT using the coupling device between the DUT and the tuning mechanism.   
   
   
       33 . The method of  claim 32 , further comprising:
 determining a new tuner setting, offset by an error from the target impedance, and measuring a new actual impedance presented to the DUT.   
   
   
       34 . The method of  claim 32 , further comprising: measuring a set of load pull parameters. 
   
   
       35 . A load pull measurement system for conducting measurements on a device-under-test (DUT), wherein impedance is controlled or varied over a set of measurement conditions and a set of parameters measured for each measurement condition, the system comprising:
 a first passive impedance controlling tuner;   a second passive impedance controlling tuner;   a first signal coupler connected between a first signal port of the DUT and the first tuner for sampling signals propagating between the first passive impedance controlling tuner and the DUT;   a second signal coupler connected between a second signal port of the DUT and the second passive impedance controlling tuner for sampling signals propagating between the DUT and the second passive impedance controlling tuner;   measurement equipment for providing excitation signals to the said first passive impedance controlling tuner, and for receiving response signals from the first and second signal couplers and the second passive impedance controlling tuner; and   wherein the measurement system is free of active impedance controlling devices which employ signal injection to synthesize an impedance.   
   
   
       36 . (canceled)