# Application Gallery

The Application Gallery features COMSOL Multiphysics tutorial and demo app files pertinent to the electrical, mechanical, fluid, and chemical disciplines. You can download ready-to-use tutorial models and demo apps with step-by-step instructions for how to create them yourself. The examples in the gallery serve as a great starting point for your own simulation work.

Use the Quick Search to find tutorials and apps relevant to your area of expertise. Log in or create a COMSOL Access account that is associated with a valid COMSOL license to download the MPH-files.

### Monopole Antenna Array

It is possible to shape the radiation pattern and steer the beam from an antenna array by controlling the relative phases and magnitudes of the input signal. This example shows how to design an active electronically scanned array (AESA) using arithmetic phase progression on each antenna element.

### Waveguide Adapter

This is a model of an adapter for microwave propagation in the transition between a rectangular and an elliptical waveguide. Such waveguide adapters are designed to keep energy losses due to reflections at a minimum for the operating frequencies. To investigate the characteristics of the adapter, the simulation includes a wave traveling from a rectangular waveguide through the adapter and into ...

### 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.

### Feasibility Study of Microstrip Patch Antenna Array Design

An antenna array is a group of radiating elements. By controlling the phase and magnitude of the input signal assigned to each antenna element and the number of array elements, the radiation pattern can be steered in a desired direction with a preferred level of gain. In this example, a 4 x 2 array of patch antennas is fed from a single feed point, with all elements fed at equal phase and ...

### 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 ...

### Antenna Crosstalk on an Airplane's Fuselage

Antenna crosstalk, or co-site interference, is problematic when multiple antennas are used on a single large platform. In this model, the interference between two identical antennas at VHF frequency is studied with an S-parameter analysis of different configurations of a receiving antenna installed on an airplane fuselage. The 2D and 3D far-field radiation patterns of a transmitting antenna are ...

### Coaxial to Waveguide Coupling

Feeding a waveguide from a coaxial cable is a straightforward way to achieve electromagnetic waves inside a waveguide. Due to its small size and circular shape, the cable contributes significantly to the overall size of the problem. It is therefore necessary to keep the cable as short as possible. This model shows how to use pairs and the Port boundary conditions to feed a rectangular ...

### Notch Filter Using a Split Ring Resonator

A split ring resonator (SRR) has a band-stop frequency response that rejects a certain range of frequency. This type of SRR structure is popularly used as a resonator itself and can be combined periodically to build artificial meta-materials. In this model, a printed SRR on a dielectric substrate is coupled to a microstrip line. The entire circuit behaves as a notch (band-stop) filter, which ...

### Balanced Patch Antenna for 6 GHz

Patch antennas are becoming more common in wireless equipment, like wireless LAN access points, cellular phones, and GPS handheld devices. The antennas are small in size and can be manufactured with simple and cost-effective techniques. Due to the complicated relationship between the geometry of the antenna and the electromagnetic fields, it is difficult to estimate the properties of a certain ...

### SMA Connectorized Wilkinson Power Divider

Some conventional three-port power dividers are resistive power dividers and T-junction power dividers. Such dividers are either lossy or not matched to the system reference impedance at all ports. In addition, isolation between two coupled ports is not guaranteed. The Wilkinson power divider outperforms the lossless T-junction divider and the resistive divider and does not have the issues ...