RF and Microwave Engineering: Fundamentals of Wireless Communications

6.13 RF Design Software

6.13.1 RF Circuit Simulators

RF circuit simulators are powerful tools that support engineers in the design and verification of complex circuits and systems. Usually different kinds of analyses are possible within such software tools, for example:

• Digital and analog simulation.
• Circuit simulation in the time-domain or frequency domain.
• S-parameter analysis with concentrated (lumped) elements.
• S-parameter analysis with distributed and coupled elements (transmission lines).
• Non-linear analysis.
• Noise parameter analysis.
• Parameter sweep and optimization.

Practical routine and straightforward issues such as matching, filter design, coupler design and so forth are commonly supported by design assistants (design guides) that apply proven formulas from standard literature. These standard designs can be further improved and adjusted by internal optimization algorithms.

In this book a lot of examples are calculated with a circuit simulator that is part of the RF design software ADS from Agilent [11]. Simulation examples include the time-domain analysis of voltage waves on transmission lines in Section 3.2 and the frequency-domain s-parameter simulation of filters in Section 6.4.

Circuit simulators generally use simplified mathematical models to describe component behaviour on the basis of voltages and currents at the terminals. Circuit simulators are therefore very efficient. However, the mathematical models have a limited range of usage. If applications exceed ...