Momentum is a 3D planar electromagnetic (EM) simulator that enables RF and microwave designers to significantly expand the range and accuracy of their passive circuits and circuit models. The ability to analyze arbitrary shapes, on multiple layers and to consider real-world design geometries when simulating coupling and parasitic effects, makes Momentum an indispensable tool for customized passive circuit design.

Momentum is capable of computing S-, Y-, and Z-parameters of general planar circuits. Microstrip, stripline, slotline, coplanar waveguide, and other circuit topologies can be analyzed quickly and accurately with Momentum. Vias that connect one layer to another can also be simulated; enabling design engineers to more fully and accurately simulate multilayer RF/MMIC's, printed circuit boards, hybrids, and Multi-Chip Modules (MCMs).

The simulator is based on the Method of Moments (MoM) technology that is particularly efficient for analyzing planar conductor and resistor geometries. It is designed to evaluate multi-layer planar geometries and generate EM accurate models that can then be used directly in ADS circuit simulators including Harmonic Balance, Convolution, and Circuit Envelope.

Circuit simulators must explicitly account for signal coupling and are also limited to designs that can be constructed only from available circuit models. The Momentum EM simulator overcomes the limitations of available models by implicitly accounting for signal coupling.

Momentum RF is a second simulation mode designed to increase simulation speed without sacrificing accuracy. The large geometries, so important to the communications industry, are quickly and easily solved with Momentum RF.

Structures under a half wavelength are particularly well suited for analysis with Momentum RF. The quasi-static solver in Momentum RF makes it possible to neglect loss mechanisms such as space and substrate radiation, providing accurate results in a fraction of the time.

Momentum-circuit co-simulation showing surface current distributionKey Features

Momentum 3D planar EM design tools come with a list of impressive features. The following key technological enablers demonstrate the advantages of Momentum as a planar EM design tool.

  • Momentum EM Simulator
    • 32-bit and 64-bit solvers
    • Internal ports aid in complex circuit modeling
    • Side wall coupling emulates physical environment
    • Box resonance calculation excludes ill-behaved S-parameters
    • DC and low frequency calculation model broad-bands accurately
    • Adaptive frequency sampling enables faster frequency sweeps
    • Edge mesh represents currents accurately while minimizing problem size
    • Automatic arc recognition for faster simulation while preserving layout
    • Optional SPICE Model Generator for integration with other simulation and design tools
    • Integrated design flow lowers overall design cost
    • Integration with ADS, Genesys & GoldenGate Design Flows
  • Momentum Optimizer
    • Geometry capture offers wide optimization choices
    • Optimization techniques are right for the job
  • Momentum Visualization
    • Visualization reveals design possibilities
    • Far-Field Plots give insight into antenna performance

When to Use Momentum 3D Planar EM Simulator

Momentum 3D planar EM modeling is especially valuable in the following design situations:

  • When Parasitic Coupling is Present: Even when circuit models are physically far apart, unexpected coupling can take place. Examples include stubs that seem sufficiently separated, but are actually inductively couple to each other because of a resonance condition, and surface waves that are bound to substrate interfaces and are excited when the right substrate parameters and frequencies are present. Momentum predicts the parasitic coupling and radiation.
  • When a Circuit Model Does Not Exist: Momentum should be used when a circuit model does not exist. For example, if a designer wants to analyze a microstrip Y-junction for which there is no model, Momentum is the solution.
  • When There are Slots in Ground Planes: Designers remove portions of ground planes for a variety of reasons, such as reducing the capacitance to ground of a spiral inductor, or to allow a via to pass through a ground plane. Momentum's ability to treat metal slots as easily as metal patterns is an added advantage. For example, Momentum performs efficient analysis of coplanar waveguide circuits.
  • When the Model Range is Exceeded: All circuit simulator models are developed with a number of range limited control parameters, (such as width, length, height, or dielectric constant,). Some models break down gradually, while others generate significant errors as soon as the range limits are exceeded. Momentum allows designers to generate highly accurate models beyond these built-in range limits.

Return to the Momentum 3D Planar EM Simulator page.