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Radar Cross Section
This tutorial model demonstrates the use of a background field in an electromagnetic scattering problem. Although this example is a boat hit by a radar, this same technique can be used in any situation where an isolated object meets electromagnetic waves from a distant source. For example, several orders of magnitude smaller, an equally common application is plasmon resonant nanoparticles. ...
Step-Index Fiber
The transmission speed of optical waveguides is superior to microwave waveguides, because optical devices have a much higher operating frequency than microwaves, enabling a far higher bandwidth. This model is an example of a single step-index waveguide made of silica glass. The inner core is made of pure silica glass with refractive index n1 = 1.4457 and the cladding is doped, with a ...
H-Bend Waveguide 3D
These examples show how to model a rectangular waveguide for microwaves in 2D and 3D. A single hollow waveguide can conduct two kinds of electromagnetic waves: transversal magnetic (TM) or transversal electric (TE) waves. The models examine a TE wave that has no electric field component in the direction of propagation. More specifically, for the models, you select the frequency and ...
Microstrip Patch Antenna
The microstrip patch antenna is used in a wide range of applications since it is easy to design and fabricate. The antenna is attractive due to its low-profile conformal design, relatively low cost and very narrow bandwidth. It is known that the antenna impedance will be higher than an accepted value if fed from the edge, and lower if fed from the center. Therefore, an optimum feed point ...
Fresnel Equations (RF)
A plane electromagnetic wave propagating through free space is incident at an angle upon an infinite dielectric medium. This model computes the reflection and transmission coefficients and compares to the Fresnel equations.
Coplanar Waveguide Bandpass Filter
Coplanar waveguide (CPW) bandpass filters can be designed using interdigital capacitors (IDCs) and short-circuited stub inductors (SSIs). This is a very efficient manufacturing method for producing bandpass filters, which can readily be implemented on a GaAs wafer. The Coplanar Waveguide Bandpass Filter tutorial model presents a design that is compact in relation to its resonant frequency and ...
Modeling of Pyramidal Absorbers for an Anechoic Chamber
In this model, a microwave absorber is constructed from an infinite 2D array of pyramidal lossy structures. Pyramidal absorbers with radiation-absorbent material (RAM) are commonly used in anechoic chambers for electromagnetic wave measurements. Microwave absorption is modeled using a lossy material to imitate the electromagnetic properties of conductive carbon-loaded foam.
Computing the Radar Cross Section of a Perfectly Conducting Sphere
A classic benchmark problem in computational electromagnetics is to solve for the radar cross section (RCS) of a sphere in free space illuminated by a plane wave. This model solves for the RCS of a metallic sphere that has a very high conductivity, which can be treated as a material with infinite conductivity. Results are compare to the analytic solution, and agreement is shown.
MRI Birdcage Coil
Magnetic resonance imaging (MRI) systems generate a magnetic flux density (B-field) to create images. Providing a homogeneous field distribution within a birdcage coil is a key factor for improving the quality of the scanned data. A homogeneous magnetic field can be found through quadrature excitation, in combination with the appropriate number of lumped elements. In this model, the magnetic ...
Finding the Impedance of a Coaxial Cable
The coaxial cable (coax) is one of the most ubiquitous transmission line structures. It is composed of a central circular conductor, surrounded by an annular dielectric, and shielded by an outer conductor. This model computes the electric and magnetic field distribution inside of the coaxial cable, analyzes the impedance, and compares the result with the analytic solution.
