Ft and Fmax are figures of merit used to benchmark the high frequency performance of RF transistors. This document describes the equations for these 2 parameters and how to improve the performance of RF transistors. devicemodelingiccapmodeling101
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It’s a common problem. You’ve just downloaded the S-parameter file for a part you’re considering using in your design; say, a high-speed connector for a backplane. Because it has a large number of ports, the first thing you want to do is inspect the quality of the data. Then, you want to use it in your simulation. But, how exactly do you wire it up and which ports do you pair?
You can go the traditional route, which involves opening the data in a text editor. But given the overall complexity and time consuming nature of the design process in general, there has got to be an easier way to deal with this data. And now there is! It’s a feature called the S-Parameter Checker and it’s available in ADS 2016 (FREE trial available here).
With S-Parameter Checker, you can easily view S-parameter file contents without ever having to setup an S-parameter test bench simulation (Figure 1). Instead, you directly plot the individual relations you want to see. You can also see the port names against each pin. The software tells you whether the file is passive or reciprocal, as well as the number of data points in the file and the frequency range it covers.
Figure 1. ADS 2016 S-Parameter Checker allows design engineers to easily rename, re-order and reduce the number of ports, enabling a new, more usable S-parameter file.
Figure 2. ADS 2016 SnP component reads port names from the file directly onto the symbol, and allows you to choose the pin orientation.
Using S-Parameter Checker isn’t the only way that using S-Parameter files in ADS 2016 is now easier than ever before.
With a new SnP component, port names can be read from the file directly onto the symbol for simulation (Figure 2). This leaves you free to choose the orientation of your pins so that all inputs are on one side and all outputs are on the other side—and that means no more crossing of wires. Once that step is accomplished, all you have to do is view, edit, place, simulate, and plot (Figure 3).
Figure 3. Using S-Parameter Checker and SnP component, using an S-parameter file for a part is now easier than ever before.
PAM-4’s ability to increase the data rate without having to enhance the hardware channel has significant hardware cost advantages. The new transmitter and receiver technologies are already showing viability for PAM-4 end-to-end links. To fully exploit the advantages of PAM-4 signaling my colleagues, Heidi Barnes & Fangyi Rao, have published a great article at Signal Integrity Journals on "Fast-Tracking Deployment in PAM-4 Applications with Commercially-Available Software and Hardware Tools". From this article, you can learn in details how a new measurement and simulation eco-system must be established and validated to fast track deployment in PAM-4 applications.