WO2009144648A2

WO2009144648A2 - System and method for performing a ruggedness measurement test on a device under test

Info

Publication number: WO2009144648A2
Application number: PCT/IB2009/052162
Authority: WO
Inventors: Iouri Volokhine
Original assignee: Nxp B.V.
Priority date: 2008-05-28
Filing date: 2009-05-23
Publication date: 2009-12-03
Also published as: WO2009144648A3

Abstract

A system and method for performing a ruggedness measurement test on a device under test (DUT) uses a first impedance creating device and a second impedance creating device, which are connected to the DUT via a coupler, to produce a combined reflection signal that corresponds to a total reflection coefficient suitable for a ruggedness measurement of the DUT. The first impedance creating device is configured to produce a first reflection signal that corresponds to a first reflection coefficient. The second impedance creating device is configured to produce a second reflection signal that corresponds to a second reflection coefficient. Each of the first and second impedance creating devices is adjustable with respect to impedance to produce the respective reflection signal. The first and second reflection signals are combined by the coupler to produce the combined reflection signal that corresponds to the total reflection coefficient.

Description

SYSTEM AND METHOD FOR PERFORMING A RUGGEDNESS

MEASUREMENT TEST ON A DEVICE UNDER TEST

Embodiments of the invention relate generally to semiconductor testing systems and, more particularly, to a system and method for performing a ruggedness measurement test on a device under test (DUT). In semiconductor testing systems, ruggedness measurements are used to evaluate the characteristics of DUTs to withstand impedance mismatch conditions. DUTs, in particular power amplifiers, operate with high efficiency, linearity and designed output power under optimal DUT input and output impedances, wherein the optimal DUT input and output impedances are usually not 50 Ohms and, in terms of location on the Smith chart, off-centered. Corresponding reflection coefficients of the optimal DUT input and output impedances can be represented by vectors from the center of the Smith chart to locations of normalized impedances. Voltage standing wave ratios (VSWRs) can be used to specify the variances of reflection coefficients during the ruggedness measurements, wherein the different reflection coefficients corresponding to a specified VSWR form a circle in the Smith chart.

In existing testing systems for performing ruggedness measurement tests for DUTs, a single impedance creating device, either an active load pull system circuitry or a tuner circuitry, is used. For a testing system using the active load pull system circuitry, a large number of states of reflection coefficients and VSWRs have to be collected, which is very time consuming. For a testing system using the tuner circuitry, a large number of tuner states have to be collected and measured in advance, which is also very time consuming. In addition, a DUT may fail because the impedance is generally unspecified during transition from one tuner state to another tuner state.

Thus, there is a need for a system and method for performing a ruggedness measurement test on a DUT that significantly reduces the number of reflection coefficient states that are required for the ruggedness measurements, which translates into time saving, and that reduces the risk of device failure during non-testing procedures. A system and method for performing a ruggedness measurement test on a DUT in accordance with embodiments of the invention uses a first impedance creating device and a second impedance creating device, which are connected to the DUT via a coupler, to produce a combined reflection signal that corresponds to a total reflection coefficient suitable for a ruggedness measurement of the DUT. The first impedance creating device is configured to produce a first reflection signal that corresponds to a first reflection coefficient. The second impedance creating device is configured to produce a second reflection signal that corresponds to a second reflection coefficient. Each of the first and second impedance creating devices is adjustable with respect to impedance to produce the respective reflection signal. The first and second reflection signals are combined by the coupler to produce the combined reflection signal that corresponds to the total reflection coefficient.

In an embodiment, a system for performing a ruggedness measurement test on a DUT includes a coupler, a first impedance creating device, and a second impedance creating device. The coupler is operably connected to the DUT to receive an original signal from the DUT. The first impedance creating device is operably connected to the coupler to receive a first signal portion of the original signal. The first impedance creating device is configured to produce a first reflection signal in response to the first signal portion. The first reflection signal corresponds to a first reflection coefficient. The first impedance creating device is adjustable with respect to impedance to produce the first reflection coefficient. The second impedance creating device is operably connected to the coupler to receive a second signal portion of the original signal. The second impedance creating device is configured to produce a second reflection signal in response to the second signal portion. The second reflection signal corresponds to a second reflection coefficient. The second impedance creating device is adjustable with respect to impedance to produce the second reflection coefficient. The first reflection signal and the second reflection signal are combined by the coupler to produce a combined signal corresponding to a total reflection coefficient suitable for a ruggedness measurement of the DUT. The total reflection coefficient is defined by the first and second reflection coefficients. In another embodiment, a system for performing a ruggedness measurement test on a DUT includes a coupler, a first impedance creating device, and a second impedance creating device. The coupler is operably connected to the DUT to receive an original signal from the DUT. The first impedance creating device is operably connected to the coupler to receive a first signal portion of the original signal. The first impedance creating device is configured to produce a first reflection signal in response to the first signal portion. The first reflection signal corresponds to a first reflection coefficient. The first reflection coefficient corresponds to a center position of an off-centered voltage standing wave ratio circle in the Smith chart. The first impedance creating device is adjustable with respect to impedance to produce the first reflection coefficient. The second impedance creating device is operably connected to the coupler to receive a second signal portion of the original signal. The second impedance creating device is configured to produce a second reflection signal in response to the second signal portion. The second reflection signal corresponds to a second reflection coefficient. The second reflection coefficient corresponds to the radius of the off-centered voltage standing wave ratio circle in the Smith chart. The second impedance creating device is adjustable with respect to impedance to produce the second reflection coefficient. The first reflection signal and the second reflection signal are combined by the coupler to produce a combined signal corresponding to a total reflection coefficient suitable for a ruggedness measurement of the DUT. The total reflection coefficient is defined by the first and second reflection coefficients.

In an embodiment, a method for performing a ruggedness measurement test on a DUT includes (a) receiving an original signal from the

DUT, (b) producing a first reflection signal in response to a first signal portion of the original signal and a first adjustable impedance, the first reflection signal corresponding to a first reflection coefficient, (c) producing a second reflection signal in response to a second signal portion of the original signal and a second adjustable impedance, the second reflection signal corresponding to a second reflection coefficient, and (d) combining the first reflection signal and the second reflection signal to produce a combined signal corresponding to a total reflection coefficient suitable for a ruggedness measurement of the DUT, the total reflection coefficient being defined by the first and second reflection coefficients. Other aspects and advantages of embodiments of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrated by way of example of the principles of the invention.

Fig. 1 is a schematic block diagram of a system for performing a ruggedness measurement test on a DUT using two impedance creating devices in accordance with an embodiment of the invention. Fig. 2 is an illustration of the Smith chart showing desired reflection coefficients on a VSWR circle, which are used to perform a ruggedness measurement test on a DUT in accordance with an embodiment of the invention.

Fig. 3 is a schematic block diagram of an exemplary system for performing a ruggedness measurement test on a DUT using an active load pull system circuitry and a tuner circuitry in accordance with an embodiment of the invention.

Fig. 4 is a schematic block diagram of another exemplary system for performing a ruggedness measurement test on a DUT using two active load pull system circuitries with two loop amplifiers in accordance with an embodiment of the invention.

Fig. 5 is a schematic block diagram of another exemplary system for performing a ruggedness measurement test on a DUT using two active load pull system circuitries with a single loop amplifier in accordance with an embodiment of the invention. Fig. 6 is a schematic block diagram of another exemplary system for performing a ruggedness measurement test on a DUT using two active load pull system circuitries with a single loop amplifier in accordance with another embodiment of the invention.

Fig. 7 is a schematic flow chart diagram of a method for performing a ruggedness measurement test on a DUT in accordance with an embodiment of the invention.

Throughout the description, similar reference numbers may be used to identify similar elements. Fig. 1 is a schematic block diagram of a system 100 for performing a ruggedness measurement test on a device under test (DUT) 102 using two impedance creating devices 108 and 110 in accordance with an embodiment of the invention. Although the depicted system includes several functional blocks described herein, other embodiments may include fewer or more functional blocks to implement more or less functionality.

The system 100 performs a ruggedness measurement test by applying reflection signals that correspond to desired reflection coefficients, which are located along the perimeter of a voltage standing wave ratio (VSWR) circle in the Smith chart. At each desired reflection coefficient on the VSWR circle, the peak current and the peak voltage are measured to evaluate the characteristics of the DUT 102 to withstand impedance mismatch conditions. As illustrated in the Smith chart of Fig. 2, the ruggedness measurement test performed by the system involves setting an optimal reflection coefficient 202, which corresponds a vector from the center of the Smith chart to the location of a normalized optimal impedances, and then evaluating the DUT 102 at desired reflection coefficients, which fulfill the VSWR specification and form a constant VSWR circle 204 in the Smith chart.

The illustrated system 100 includes the DUT 102, a real-time measurement circuitry 104, a power coupler 106, the first impedance creating device 108, and the second impedance creating device 110. The DUT is a semiconductor device that outputs an original signal. As an example, the DUT may be a power amplifier. The real-time measurement circuitry operates to sample the original signal coming from the DUT and a reflection signal propagating toward the DUT to measure the reflection coefficients for the DUT. The real time measurement circuitry may use directional couplers to sample the original and reflected signals, which may introduce loss or gain.

The first impedance creating device 108, which may be an active load pull system circuitry, is operably connected to the coupler 106 to receive a first signal portion of the original signal from the DUT 102 via the coupler. The first impedance creating device is configured to produce a first reflection signal in response to the first signal portion, wherein the first reflection signal corresponds to a first reflection coefficient. The first impedance creating device is adjustable with respect to impedance to produce the first reflection coefficient. Thus, the first impedance creating device provides variable impedance.

The second impedance creating device 110, which may be either an active load pull system circuitry or a tuner circuitry, is operably connected to the coupler 106 to receive a second signal portion of the original signal from the DUT 102 via the coupler. The second impedance creating device is configured to produce a second reflection signal in response to the second signal portion, wherein the second reflection signal corresponds to a second reflection coefficient. The second impedance creating device is adjustable with respect to impedance to produce the second reflection coefficient. Thus, the second impedance creating device also provides variable impedance. In an embodiment, the difference between the operating frequency of the first impedance creating device and the operating frequency of the second impedance creating device is close, e.g., within the bandwidth of operation of the impedance creating devices usually a few megahertz (MHz), i.e., less than ten MHz.

The coupler 106 is operably connected to the DUT 102 via the realtime measurement circuitry 104 to receive the original signal from the DUT. The coupler combines the first reflection signal from the first impedance creating device 108 and the second reflection signal from the second impedance creating device 110 to produce a combined signal corresponding to a total reflection coefficient suitable for a ruggedness measurement of the DUT. Thus, the total reflection coefficient is defined by the first and second reflection coefficients of the first and second reflection signals. As shown in Fig. 1, the coupler includes three ports 1, 2 and 3. The port 1 of the coupler is connected to the DUT via the real-time measurement circuitry, while the ports 2 and 3 of the coupler are connected to the first and second impedance creating devices, respectively.

As shown in Fig. 1 , the total reflection coefficient can be written as, f_r = S₂₁S₁₂F₁ + S₃₁S₁₃F₂ , where S₁₂, S₂₁, S₃₁, S₁₃ are the coupler's transmission coefficients, F₁ is the first reflection coefficient and F₂ is the second reflection coefficient. The contribution of F₁ or F₂ to the total reflection coefficient F₁, can be controlled by adjusting the coupler's transmission coefficients. In operation, the DUT 102 outputs an original signal. The first impedance creating device 108 receives a first signal portion of the original signal via the coupler 106 and produces a first reflection signal corresponding to a first reflection coefficient, which corresponds to the center position of an off-centered VSWR circle in the Smith chart, such as the optimal reflection coefficient 202 of the off-centered VSWR circuit 204 of Fig. 2. The second impedance creating device 110 receives a second signal portion of the original signal via the coupler 106 and produces a second reflection signal corresponding to a second reflection coefficient, which corresponds to the radius and the phase of the off-centered VSWR circle in the Smith chart. The coupler then combines the first reflection signal and the second reflection signal to produce a combined signal corresponding to the total reflection coefficient suitable for a ruggedness measurement of the DUT. In order to produce other desired total reflection coefficients on the VSWR circle, the impedance of the second impedance creating device is adjusted to modify the combined signal according to the desired total reflection coefficients. The real-time measurement circuitry 104 samples the original signal and the combined signal to measure reflection coefficients being applied to the DUT.

Fig. 3 is a schematic block diagram of an exemplary system 300 for performing a ruggedness measurement test on the DUT 102 using an active load pull system circuitry 308 as the first impedance creating device and a tuner circuitry 310 as the second impedance creating device in accordance with an embodiment of the invention. Although the depicted exemplary system 300 includes several functional blocks described herein, other embodiments may include fewer or more functional blocks to implement more or less functionality.

The depicted system 300 includes the DUT 102, the real-time measurement circuitry 104, the coupler 106, the active load pull system circuitry 308 and the tuner circuitry 310. As stated above, the DUT is a semiconductor device that outputs an original signal. As an example, the DUT may be a power amplifier. The real-time measurement circuitry operates to sample the original signal coming from the DUT and a reflected signal propagating toward the DUT to get the reflection coefficients for the DUT. The real time measurement circuitry may use directional couplers to sample the original and reflected signals, which may introduce loss or gain.

The active load pull system circuitry 308 includes a directional coupler 312, a variable attenuator 314, a variable phase shifter 316, a variable band pass filter 318, and a loop amplifier 320. The active load directional coupler extracts a first signal portion of the original signal from the DUT 102. The variable band pass filter then filters the extracted signal to desired frequencies. The variable attenuator then attenuates the filtered signal to get desired magnitude of the first refection coefficient, which corresponds to the center position of an off-centered VSWR circle in the Smith chart, such as the optimal reflection coefficient 202 of the off-centered VSWR circuit 204 of Fig. 2. The variable phase shifter adjusts the phases of the first refection coefficient, and finally the loop amplifier amplifies the signal to compensate losses introduced by the previous components and other components of the depicted system. The active load pull system circuitry, for example, may be an active tuner manufactured by Progettazione Alta Frequenza (PAF).

The tuner circuitry 310, which may be either a mechanical tuner or an electromechanical tuner, includes a mechanical transmission line 322 and at least one probe 324. Probe positions of the tuner circuitry define the second refection coefficient. The phase of the second refection coefficient is adjusted by moving the probe(s) along the transmission line and the magnitude of the second reflection coefficient is adjusted by changing the distance(s) between the probe(s) and the transmission line, which generally affects the phase of the second reflection coefficient as well. The tuner circuitry, for example, may be an electromechanical tuner or a mechanical tuner manufactured by Maury Microwave Corporation or Focus Microwaves.

The tuner circuitry 310 receives a second signal portion of the original signal from the DUT 102 via the coupler 106 and adjusts the impedance to produce a second reflection signal corresponding to the second reflection coefficient, which corresponds to the radius and the phase of the off-centered VSWR circle in the Smith chart, such as the VSWR circle 204 of Fig. 2. The operation of the tuner circuitry involves setting height(s) of the probe(s) to select the radius of the off-centered VSWR circle, and then moving the probe(s) over the transmission line to travel over the VSWR circle to change the phase. In an embodiment, the difference between the operating frequency of the tuner circuitry and the operating frequency of the active load pull system circuitry 308 is close. The tuner circuitry is terminated by a terminator 318, which connects to the ground and has an impedance of 50 Ohm by default.

The coupler 106 combines the first reflection signal from the active load pull system circuitry 308 and the second reflection signal from the tuner circuitry 310 to produce a combined signal corresponding to a total reflection coefficient suitable for the ruggedness measurement of the DUT 102. The total reflection coefficient is defined by the first and second reflection coefficients.

In operation, the DUT 102 outputs an original signal. The active load pull system circuitry 320 receives a first signal portion of the original signal via the coupler 106 and produces a first reflection signal corresponding to a first reflection coefficient, which corresponds to the center position of an off-centered VSWR circle in the Smith chart, such as the optimal reflection coefficient 202 of the off- centered VSWR circuit 204 of Fig. 2. The tuner circuitry 312 receives a second signal portion of the original signal via the coupler and produces a second reflection signal corresponding to a second reflection coefficient, which corresponds to the radius and the phase of the off-centered VSWR circle in the Smith chart. The coupler 106 combines the first reflection signal and the second reflection signal to produce a combined signal corresponding to a total reflection coefficient suitable for a ruggedness measurement of the DUT. In order to produce other desired total reflection coefficients on the VSWR circle, the impedance of the tuner circuitry is adjusted to modify the combined signal according to the desired total reflection coefficients. The real-time measurement circuitry 104 samples the original signal and the combined signal to measure reflection coefficients being applied to the DUT.

The system 300 provides independent control of the center position of the VSWR circle, and the radius and the phase of the VSWR circle, and provides smooth transition between impedances.

Because the tuner circuitry 310 is limited in achievable VSWR, a second active load pull system circuitry may instead be used for high VSWR values. This second active load pull system circuitry can be used as a replacement of the tuner circuitry to produce a second reflection signal corresponding to a second reflection coefficient, which corresponds to the radius and the phase of an off-centered VSWR circle in the Smith chart.

Fig. 4 is a schematic block diagram of another exemplary system 400 for performing a ruggedness measurement test on the DUT 102 using two active load pull system circuitries 408A and 408B in accordance with an embodiment of the invention. The depicted system includes the DUT 102, the real-time measurement circuitry 104, the coupler 106 and the active load pull system circuitries 408A and 408B. Each of the active load pull system circuitries 408A and 408B is connected to the real-time measurement circuitry through the directional coupler 302 and a power splitter 402. Each of the active load pull system circuitries 408A and 408B includes the variable attenuator 314, the variable phase shifter 316, the variable band pass filter 318, and the loop amplifier 320. Although the depicted exemplary system 400 includes several functional blocks described herein, other embodiments may include fewer or more functional blocks to implement more or less functionality.

The active load pull system circuitry 408A operates in a similar manner as the active load pull system circuitry 308 of the system 300 to produce a first reflection signal corresponding to a first reflection coefficient, which corresponds to the center position of an off-centered VSWR circle in the Smith chart, such as the optimal reflection coefficient 202 of the off-centered VSWR circuit 204 of Fig. 2. The active load pull system circuitry 408B operates to produce a second reflection signal corresponding to a second reflection coefficient, which corresponds to the radius and the phase of the off-centered VSWR circle in the Smith chart. The operation of the active load pull system circuitry 408B involves setting the variable attenuator 316 and the loop amplifier 320 to select the radius of the off-centered VSWR circle, and then adjusting the variable phase shifter 318 to travel over the VSWR circle to change the phase of the off-center VSWR circle. Fig. 5 is a schematic block diagram of another exemplary system 500 for performing a ruggedness measurement for a DUT using two active load pull system circuitries 508A and 508B in accordance with an embodiment of the invention. The depicted system 500 includes the DUT 102, the real-time measurement circuitry 104, the coupler 106 and the active load pull system circuitries 508A and 508B. The active load pull system circuitries 508A and 508B are similar to the active load pull system circuitries 408A and 408B of the system 400 of Fig. 4. However, in this embodiment, each of the active load pull system circuitries 508A and 508B does not include a loop amplifier. Rather, the active load pull system circuitries 508A and 508B includes a common loop amplifier 520. The active load pull system circuitry 508A operates in a similar manner as the active load pull system circuitry 408A of the system 400 of Fig. 4. Similarly, the active load pull system circuitry 508B operates in a similar manner as the active load pull system circuitry 408B of the system 400 of Fig. 4.

Although the depicted exemplary system 500 includes several functional blocks described herein, other embodiments may include fewer or more functional blocks to implement more or less functionality.

Fig. 6 is a schematic block diagram of another exemplary system 600 for performing a ruggedness measurement test on the DUT 102 using the two active load pull system circuitries 508A and 508B in accordance with another embodiment of the invention. The depicted system 600 includes the DUT 102, the real-time measurement circuitry 106, the coupler 104 and the active load pull system circuitries 508A and 508B. Thus, the system 600 is similar to the system 500 of Fig. 5. However, in the system 600, the real-time measurement circuitry is located between the coupler 312 and the loop amplifier 520, whereas in the system 500, the real-time measurement circuitry is located between the DUT 102 and the coupler. Although the depicted exemplary system 600 includes several functional blocks described herein, other embodiments may include fewer or more functional blocks to implement more or less functionality.

Fig. 7 is a schematic flow chart diagram of a method for performing a ruggedness measurement test on a DUT in accordance with an embodiment of the invention. At block 702, an original signal is received from the DUT. At block 704, a first reflection signal is produced in response to a first signal portion of the original signal and a first adjustable impedance corresponding to a first reflection coefficient. At block 706, a second reflection signal is produced in response to a second signal portion of the original signal and a second adjustable impedance corresponding to a second reflection coefficient. At block 708, the first reflection signal and the second reflection signal are combined to produce a combined signal corresponding to a total reflection coefficient suitable for a ruggedness measurement of the DUT, the total reflection coefficient being defined by the first and second reflection coefficients. Although the operations of the method herein are shown and described in a particular order, the order of the operations of the method may be altered so that certain operations may be performed in an inverse order or so that certain operations may be performed, at least in part, concurrently with other operations. In another embodiment, instructions or sub-operations of distinct operations may be implemented in an intermittent and/or alternating manner. Embodiments of the system and method for performing a ruggedness measurement test on a DUT can be applied to various semiconductor testing systems, in particular, power amplifier measurement systems, which may conduct on-wafer measurements. Although specific embodiments of the invention have been described and illustrated, the invention is not to be limited to the specific forms or arrangements of parts so described and illustrated. The scope of the invention is to be defined by the claims appended hereto and their equivalents.

Claims

What is claimed is:

1. A system for performing a ruggedness measurement test on a device under test, the system comprising: a coupler operably connected to the device under test to receive an original signal from the device under test; a first impedance creating device operably connected to the coupler to receive a first signal portion of the original signal, the first impedance creating device being configured to produce a first reflection signal in response to the first signal portion, the first reflection signal corresponding to a first reflection coefficient, the first impedance creating device being adjustable with respect to impedance to produce the first reflection coefficient; and a second impedance creating device operably connected to the coupler to receive a second signal portion of the original signal, the second impedance creating device being configured to produce a second reflection signal in response to the second signal portion, the second reflection signal corresponding to a second reflection coefficient, the second impedance creating device being adjustable with respect to impedance to produce the second reflection coefficient, wherein the first reflection signal and the second reflection signal are combined by the coupler to produce a combined signal corresponding to a total reflection coefficient suitable for a ruggedness measurement of the device under test, the total reflection coefficient being defined by the first and second reflection coefficients.

2. The system of claim 1, wherein the first impedance creating device includes an active load pull system circuitry.

3. The system of claim 2, wherein the active load pull system circuitry includes a variable attenuator, a variable phase shifter, and a variable band pass filter.

4. The system of claim 2, wherein the second impedance creating device includes a tuner circuitry.

5. The system of claim 4, wherein the tuner circuitry includes a mechanical transmission line and at least one probe.

6. The system of claim 2, wherein the second impedance creating device includes another active load pull system circuitry.

7. The system of claim 6, wherein each of the active load pull system circuitry and the another active load pull system circuitry includes an amplifier.

8. The system of claim 6, wherein the active load pull system circuitry and the another active load pull system circuitry include a single amplifier.

9. The system of claim 1, wherein the difference between the operating frequency of the first impedance creating device and the operating frequency of the second impedance creating device is within a bandwidth of operation of the first and second impedance creating devices.

10. A method for performing a ruggedness measurement test on a device under test, the method comprising: receiving an original signal from the device under test; producing a first reflection signal in response to a first signal portion of the original signal and a first adjustable impedance, the first reflection signal corresponding to a first reflection coefficient; producing a second reflection signal in response to a second signal portion of the original signal and a second adjustable impedance, the second reflection signal corresponding to a second reflection coefficient; and combining the first reflection signal and the second reflection signal to produce a combined signal corresponding to a total reflection coefficient suitable for a ruggedness measurement of the device under test, the total reflection coefficient being defined by the first and second reflection coefficients.

1 1. The method of claim 10, wherein the producing of the first reflection signal includes producing the first reflection signal using an active load pull system circuitry.

12. The method of claim 1 1, wherein the active load pull system circuitry includes a variable attenuator, a variable phase shifter, and a variable band pass filter.

13. The method of claim 1 1, wherein the producing of the second reflection signal includes producing the second reflection signal using a tuner circuitry.

14. The method of claim 13, wherein the tuner circuitry includes a mechanical transmission line and at least one probe.

15. The method of claim 1 1, wherein the producing of the second reflection signal includes producing the second reflection signal using another active load pull system circuitry.

16. The method of claim 15, wherein each of the active load pull system circuitry and the another active load pull system circuitry include an amplifier.

17. The method of claim 15, wherein the active load pull system circuitry and the another active load pull system circuitry include a single amplifier.

18. A system for performing a ruggedness measurement test on a device under test, the system comprising: a coupler operably connected to the device under test to receive an original signal from the device under test; a first impedance creating device operably connected to the coupler to receive a first signal portion of the original signal, the first impedance creating device being configured to produce a first reflection signal in response to the first signal portion, the first reflection signal corresponding to a first reflection coefficient, the first reflection coefficient corresponding to a center position of an off-centered voltage standing wave ratio circle in the Smith chart, the first impedance creating device being adjustable with respect to impedance to produce the first reflection coefficient; and a second impedance creating device operably connected to the coupler to receive a second signal portion of the original signal, the second impedance creating device being configured to produce a second reflection signal in response to the second signal portion, the second reflection signal corresponding to a second reflection coefficient, the second reflection coefficient corresponding to the radius of the off-centered voltage standing wave ratio circle in the Smith chart, the second impedance creating device being adjustable with respect to impedance to produce the second reflection coefficient, wherein the first reflection signal and the second reflection signal are combined by the coupler to produce a combined signal corresponding to a total reflection coefficient suitable for a ruggedness measurement of the device under test, the total reflection coefficient being defined by the first and second reflection coefficients.

19. The system of claim 18, wherein the first impedance creating device includes an active load pull system circuitry.

20. The system of claim 19, wherein the second impedance creating device includes a tuner circuitry.