Unique Amplifier and Impedance-Matching Design Tools
Ampsa provides its customers with a structured process for designing robust high-performance RF and microwave amplifiers. Clipping theory has been developed to a fully useful form in the ADW. Design features include power contours with maximum efficiency lines, as well as second harmonic clipping contours and continuous mode options. Power parameters are used to provide load-pull capabilities in the ADW, and are also used to calculate the power and the efficiency.
Transistors are modelled by using S-parameters and IV-curves. The intrinsic load terminations of the transistor are controlled in the ADW.
Ideally the harmonic performance should not be influenced strongly by the external load terminations. Transmission zeros are required in the load matching network for this purpose. The harmonic open or short provided by such a null should ideally be transformed to the intrinsic harmonic termination required for the desired performance. The synthesis process in the ADW now also allows for this.
The modeling approach in the ADW is ideal when an accurate non-linear model is not yet available for a transistor. When a model is available, the ADW model can be fine-tuned by comparing the results obtained.
Sophisticated optimization is provided in the ADW - This includes optimization of the intrinsic load terminations (continuous modes are also provided for), as well as analysis and optimization for non-linear Cds.
Impedance matching in the Amplifier Design Wizard and the Matching Wizard is based on systematic searches on the transformation Qs, or systematic searches on the transmission delay and the associated design parameter. When commensurate distributed matching networks are synthesized in the ADW, the line lengths are fixed by the user and the line widths are the variables. The line widths are fixed in non-commensurate networks, and the line lengths are the variables. A search can now also be performed on the main-line line length (commensurate solutions) or characteristic impedance (non-commensurate solutions). This eliminates manual experimentation to find the best solution to a matching problem.
Harmonic traps can be introduced in the design via fixed-element sections added to the matching network. Information on potential second-harmonic and third-harmonic traps is provided during the load-pull phase. The viability of these traps is also considered - Significant loading at the fundamental frequencies should be avoided.
The synthesis algorithm for non-commensurate networks was also extended to introduce second-harmonic and/or third-harmonic traps in the synthesized networks. A shunt capacitive branch in a matching network can now control the fundamental-frequency performance and can also provide resonance at the transmission-null frequency targeted. This also applies to lumped capacitors or inductors. Each shorted stub branch can also be complemented with an open-ended stub branch for dual control. Different trap frequencies can be specified for the open-ended and the shorted stub branches.
The electrical lengths of the open-ended or shorted stubs in a commensurate network can also be set for harmonic suppression.
32-bit, as well as 64-bit versions of the ADW and the MW are available.
Version 21 (Build 13990) of the ADW has been released. In addition to the new harmonic trapping features, and extensions in the optimization of the intrinsic load terminations, tuning of the selected element in an ADW schematic is now also allowed. When the load matching network for a power stage is synthesized, the intrinsic impedance presented to the transistor can now also be viewed when the solutions are compared in the Impedance-Matching module. With this capability it is much easier to select the best solution to the matching problem.
Many inconveniences present in earlier releases were eliminated in Version 21 - This includes a significant increase in the number of frequencies allowed during synthesis.
Training can be provided on the software, as well as amplifier design in general and the wizards can be customized to improve the design flow for specific customers.
In addition to the option to buy a permanent license for the ADW, annual subscription options are now also provided (see the price lists provided under Downloads).