Bringing RF Ideas to Life - The Basics of RF Simulations

Blog Post created by annamccowan Employee on Jun 26, 2017

         For engineering students and professionals alike, ADS simulations are a dream come true. A software that does all the calculations for me? Count me in!


         As today’s circuits grow more and more complex, the processes involved in creating, testing, and simulating them tend to follow suit. RF engineers face many challenges in RF design. With vast applications and flourishing technology, engineers need an efficient, easy-to-use workspace to construct their innovative creations.


         In his webcast, RF Simulations Basics, Andy Howard, Senior Applications Engineer and EEsof Applications Expert for 30 years, guides us through the basics of RF Simulation in ADS, showing how it is a valuable tool with multiple applications. For those just getting introduced to RF simulations, this webcast is a great resource for understanding how to perform RF simulations and why. Andy provides six prevalent applications for RF Simulations, two of which I will discuss here, that show us why ADS is the integral part in bringing engineering ideas to life.



Figure 1: ADS helps RF engineers bring their ideas to fruition with its efficient, easy-to-use RF simulation guides.



RF Simulations with ADS

ADS offers a comprehensive set of advanced simulation tools, integrated into a single environment. In the webcast, Andy gives you a feel for what it’s like to run the ADS software. He shows how an ADS user can design a simple block diagram using models. These models represent transmission lines, transistors, capacitors, etc. These are “the building blocks of effective simulations.” Simulating S-Parameters of your RF design is similar to using a network analyzer; however, with ADS you can combine multiple blocks with several different parameters. There is no limit to the number of ports.


The interface allows you to adjust the parameters of each component as you place it in your schematic and set frequency limits. When the design is complete, Andy shows how you can view the Data Display window and tune the component values simultaneously. This provides an excellent visualization of how your design truly depends on the different component values.



Figure 2. With ADS, users can view the Data Display window and tune the component values simultaneously.


What can be achieved with RF Simulation?


1. Better receiver performance for all your communication devices.

The applications of ADS are vast. A simple example Andy gives is an FM Radio Receiver. The simulation provides data at each node of the block diagram, allowing him to determine precisely where the receiver has performance degradation. He also views a spectrum of a particular node, which can indicate spectral content. By doing this example in ADS, the designer can more quickly see which components are causing the degradation.  The engineer can make more accurate predictions about their design without having to do many messy calculations. ADS also allows you to tune the parameters of your devices within the block diagram, allowing you to make adjustments as needed. 



Figure 3: The simulation of an FM Radio Receiver provides data at each node of the block diagram, allowing one to determine the precise location of performance degradation. Simulation done by ADS.




2. Integration of Multiple Technologies

The coupling of multiple technologies is a challenge often faced by RF designers, especially now as multi-tech devices are becoming more common place. Therefore, the need for compatibility between the technologies is imperative. For example, many companies use ADS to design parts such as a Multi-Chip RF Front End Module, as it is popularly used to power smart phones and tablets. ADS allows designers to take a pre-existing module, and virtually mount it on a board. Using multiple technologies can often cause performance degradation and increased simulation times. ADS is unique in its ability to ensure compatibility between different modules and technologies.



Figure 4. ADS allows designers to take a pre-existing module and virtually mount it on a board, allowing RF designers to couple multiple technologies into one simulation. Simulation done by ADS.


         These are only two of many applications of RF Simulations through ADS. Andy provides insight into these as well as four other applications of RF Simulations, including Electro-Thermal Analysis and High Speed Digital Design. He also delves into the different types of simulation engines which allow you to analyze your design’s harmonic balance results and transient simulations.

         Andy has over 15 years of experience designing and simulating circuits. For those looking for an introduction to the fundamentals of RF simulations, Andy provides a well-structured one-hour lecture that describes the multiple uses of RF design software. With these fundamentals, RF students and professionals can easily make their ideas into a reality.