IVCAD 3.10.2

IVCAD MT930C offers a modern and efficient methodology for load-pull measurements. Low-loss couplers, inserted between the tuners and DUT, are connected to a VNA to allow real-time measurement of a and b-waves at the DUT reference plane, enabling vector information not normally made available with traditional setups.

Traditional load pull was the first system to automatically measure device performances under various source and load impedances. These test benches are using pre-characterized passive tuners for impedance matching and scalar power detectors for measurements.
Based on the pre-characterization of the impedance tuners, the measurements are relying on the set of measured or interpolated s-parameters of the tuners at different impedance conditions. Raw measurements from scalar instruments (Power meters) are de-embedded, in real time, to the DUT reference plane using the loss calculation of tuners and other components in the setup.

The MT930D2* bench architecture is an upgrade to the MT930D1. It enables harmonic load pull and wideband modulated signal measurements.
Spectrum analyzer (or multiplexer with several power sensors) can be added to read specific power at each frequency as well as power at intermodulation frequencies if driven by a two-tone signal. Depending on the signal source and analyzer, CW, pulsed-CW, single-tone, two tone and/or modulated signals, and their respective measurement parameters, can be achieved. *MT930D1 is pre-required for MT930D2.

MT930E is a standalone module which enables DC-IV curves for parametric analysis of transistors. The library contains a wide range of drivers for commercial application related instruments. Selecting the DC supplies associated with precision multimeters or SMUs will enable semiconductor parametric analysis in safe operating conditions, using stop conditions given by maximum input and output currents , or maximum DC power compliances.
Start , Stop and Step values can be defined to sweep input voltage or current for different output voltages.

MT930F is an add-on module for MT930E which enables S-parameters measurements in CW mode during a DC IV bias point sweep. DC and RF hardware settings are defined in a user-friendly interface where different parameters can be set (frequency sweeps, IF bandwidth, averaging, VNA ports used, VNA calibration files etc.) and saved in one single configuration file for future use. IVCAD supports main commercial VNAs for which it provides robust drivers for each model.

MT930GA is an add-on module for MT930C Vector-Receiver Load Pull which enables time-domain large signal analysis and waveform reconstruction.  When used with supported VNAs and comb generators (harmonic phase references) it does not require any third-party nonlinear VNA software. The LSA add-on records the phase dependency of harmonic content allowing a- and b-waves, voltage and current waveforms plotting as well as dynamic load lines display for each measurement state (impedance/power/bias). All measurements are be de-embedded to the device reference plane.

MT930H* active load pull module allows the control of ΓL as the ratio between the reflected- and forward-travelling waves at the output of the DUT . A generalized form of the formula can be written as ΓL = (a2/b2). The wave b2 is taken as the wave coming from the device, while a2 is the reflected wave seen by the device under test, coming either from a passive circuit, an active circuit or a combination of both for hybrid load pull.

MT930J is a stand-alone module for advanced Pulsed IV measurements using dedicated hardware (e.g., AM3200 AMCAD’s Pulsed IV system ). IVCAD enables the visualization of trapping phenomena, gate lag and drain lag, on GaN transistors, but also dynamic self heating on different transistor technologies. The module allows a quasi-instantaneous visualization of pulsed IV characteristics as a function of varying quiescent bias point and temperature of the base plate.

MT930K is an add-on module to MT930J which enables synchronized Pulsed S-Parameter measurements in conjunction with Pulsed IV. This option will enable controlling different vector network analyzers. AMCAD recommends to use VNAs equipped with Pulsed S-parameter options to achieve pulsed measurements in asynchronous mode, while insuring a great measurement dynamic range , even with low duty cycles needed to avoid self-heating effects. These conditions are mandatory for model extraction measurements.

MT930L scripting tool allows the user to fully customize the measurement sequence and the visualization tools.  Using a library of pre-encoded functions and GUIs used as building blocks by IVCAD, it is possible to automatize a set of measurements with one push button. Used in conjunction with the syntax interpreter and the search engine to find the required functions, the scripting language leverages your IVCAD platform to unrivaled solution in terms of flexibility and powerfulness in semiconductor industry.

MT930M1 Linear Model Extraction is used easily to determine the extrinsic (parasitic elements) and intrinsic parameters of III-V and LDMOS transistors. Linear modeling fits measured data to linear model equations and can be automatically optimized or manually tuned to solve for values of the extrinsic (Rg, Lg, Cpg, Rd, Ld, Cpd, Rs, Ls) and intrinsic parameters.

Pulsed S parameters measured with the MT930K module will be used to extract the nonlinear capacitances models through built-in AMCAD’s or user-defined equations. Pulsed IV measurements with the MT930J will be used to extract the nonlinear input diodes and the output current source parameters using AMCAD’s or used-defined equations. Export functionalities and specific templates are then used to upload the model into commercial simulators and include thermal and trapping effects. Finally, the model is refined against VNA based load pull measurements for better approximation of the model in the desired application.

Pulsed S parameters will be used to extract different LDMOS nonlinear capacitances models through built-in AMCAD’s or user-defined equations. Pulsed IV measurements will be used to extract specific LDMOS output current source parameters using AMCAD’s or user-defined equations. Export functionalities and specific templates are then used to upload the model into commercial simulators and include thermal effects. Finally, the model is refined against VNA based load pull measurements for better approximation of the model in the desired application.

Nevertheless, there are some cases where the time needed to extract a compact model is not compatible with the project timeline (one or two weeks maximum) or budget. In this latter case, the EPHD  is the right candidate because it allows extracting a model on the fly from load-pull measurements, which saves considerable design time. The ability of this model to predict the overall design performances without any convergence issues for harmonic balance simulations has been proved even for extrapolated load conditions, during the simulation, and with the load impedances used during the load pull measurement process. Therefore, this new model is a promising candidate for the design of power amplifiers of future telecommunication systems due to its robustness, flexibility, reliability under ROI constraints.

Dockable windows allow users to create and save custom IVCAD environments. Templates allow users to save their preferred visualization graphs and recall or share with colleagues. Data Editor allows users to create new parameters based on equations and visualize alongside measurement data. Export allows users to save graphs and plots as JPG or PDF files for reporting. Visualization modules are compatible with IVCAD and common commercial data formats.

• Extended I(V) Viewer allows Dynamic pulsed IV visualization, as a function of time, to check measurement relevance and observe critical data variation such as dynamic self-heating.
• I(V) wafer Mapping uses I(V) data to observe the spread of DUT DC performances at wafer scale for interpolated parameters.
• Advanced S Parameter Viewer allows plotting stability, operating and Maximum Gain circles as function of frequency or bias parameters.
• Extended Load Pull Viewer plots interpolated load pull contours versus power levels; time domain load pull waveforms and, thanks to a patented ‘Magic Source pull’ process, it can dynamically emulate equivalent source pull measurements such as the transistor's transducer gain.

• IV Tools – compute gm/gd, convert IV data sets, interpolate/extrapolate IV points.
• S-parameters – TRL fixture extraction, interpolate/extrapolate S-parameters.
• De-embedding – intrinsic de-embedding of S-parameters and VNA based load pull measurements based on transistor linear model.
• Converter – mathematical calculator for converting phase, electrical length, power, VSWR, impedance.

STAN tool is a patented solution capable of  assessing the stability of RF & Microwave circuits, which is a critical step in the design flow. In comparison with other methodologies (Rollet & Nyquist Criterion, NDF …), STAN is a unique solution that brings together all the following advantages : Fast, Rigourous, User Friendly, and ready to use with commercial CAD software. The STAN approach calculates a single-input, single-output (SISO) transfer function for a circuit of interest linearized around a given steady state. A simulated frequency response of the linearized circuit is fitted to a rational polynomial transfer function by means of frequency-domain identification algorithm. If no poles on the right-half plane (RHP) are found, it is considered stable.

IVCAD includes a live visualization tool for each measurement module. A predefined structure with multiple graphs contains a measurement table section for fast identification of all the measured and calculated parameters. Configurable graphs are also available with full customization of the displayed parameters.
Measurement data can be exported to standard formats like CSV and MDIF.

In the case of a scalar setup, the calibration procedure is based on power measurements using power meters and signal generators. For vector setups, the Calibration of the Vector Network Analyzer (VNA) is necessary to extract the error terms. Furthermore, depending on the VNA configuration. To minimize the source of errors, IVCAD provides a state-of-the-art calibration wizard that relies on the schematic setup to identify the type of Calibration that is possible to perform and guides the end-user through all the steps, including the validation process to verify and assess the expected accuracy.

The auto tuner de-embedding wizard is a unique feature in the VRLP setup in IVCAD that allows the recalculation of the tuner calibration and its related error terms when the tuners' terminations (Source or load) change after the setup calibration. This can happen if we need to change one of the setup components to accommodate the device (switch to higher power handling or wider frequency band components and change a damaged one). The auto de-embedding wizard saves a considerable amount f time and avoids re-calibrating the full system when only a passive device needs to be replaced.

High power devices require measurements in pulsed mode to mitigate thermal effects. Pulsed options often add complexity to settings. Therefore, IVCAD provides a simple user interface for full control of the pulse generators, the receivers, and the trigger signals. Different instruments in the setup can be set with appropriate timings for the pulse setting and pulse measurements. To simplify the task for the end-user, IVCAD embeds a Chronogram that describes, on a time axis, the pulse mode settings, and a configuration panel where all the timing specifications can be set at once.

RF Transistor measurements can be particularly challenging when dealing with DC power supply control. IVCAD allows the DC power supply remote control of up to 6 accesses with associated DC or pulsed voltage and current measurements from the power supplies or using DC precision multimeters and oscilloscopes for pulsed current measurements when the RF signal is pulsed by an RF pulse modulator.
It is very easy to enter various and numerous DC power supply settings for the software GUI without any specific programming skills.

It is a must-have to measure accurate DC voltages at the Device Under Test reference plane (DUT), whatever the current consumption. Because the current can flow through a cable with a parasitic serial resistance or through a shunt resistor for differential current measurements, the voltage drop across the serial or possibly parallel resistors must be taken into account to measure the true voltage at the DUT bias access. A resistive network can be configured into the IVCAD DC power supply user interface to de-embed the measurements and the voltage settings to the DUT reference plane.