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 ...
A bowtie antenna patterned on a dielectric substrate is optimized by changing the length of the arms and the flare angle to reduce the magnitude of S11, the reflection coefficient. The two geometric dimensions that are used as design variables directly control the size and shape of the antenna, and also affect the dimensions of the dielectric substrate. The gradient-free Nelder-Mead optimization ...
The excited TE mode from a circular waveguide passes through the corrugated inner surface of a circular horn antenna where TM mode is also generated. When combined, these two modes give lower cross-polarization at the antenna aperture than the excited TE mode. This example is designed using a 2D axisymmetric model.
A Branch Line Coupler (Quadrature 90° Hybrid) is a four-port network device with a 90° phase difference between two coupled ports. The device can be used for a single antenna Transmitter/Receiver system or an I/Q signal splitter/combiner. The objective of this model is to compute the S-parameters and to observe the matching, isolation, and coupling around the operating frequency.
A Biconical antenna is a type of wideband antenna with omni-directional radiation pattern in the H-plane similar to a dipole antenna. A coaxial feed is connected to the radiators using two 90 degree bent arms. The model shows that the biconical antenna works well in applications requiring an omnidirectional radiation pattern and wide bandwidth.
A large reflector can be modeled easily with the 2D axisymmetric formulation. In this model, the radius of the reflector is greater than 20 wavelengths and the reflector is illuminated by an axial feed circular horn antenna. The simulated far-field shows a high-gain sharp beam pattern
An Electromagnetic Band Gap (EBG) structure can be used to increase the isolation between antennas close to each other. The decoupling effect is not only a function of frequency but also polarization and coupling-plane configuration. When designing an EBG structure, one needs to make sure to not apply an incorrect frequency and polarization, since this would increase the coupling between ...
RF coils are important in numerous applications ranging from wireless technology to MRI scanning equipment. This introductory tutorial model demonstrates how to find the fundamental resonance frequency of an RF coil as well as how to perform a frequency sweep to extract the coil's Q-factor.
The dipole antenna is one of the most straightforward antenna configurations. It can be realized with two thin metallic rods that have a sinusoidal voltage difference applied between them. The length of the rods is chosen such that they are quarter wavelength elements at the operating frequency. Such an antenna has a well known torus-like radiation pattern.
A cascaded cavity filter provides much better bandpass filter performance compared to a single cavity. Out-of-band rejection improves dramatically using a cascaded design. This model uses three rectangular cavity filters coupled via slots. The calculated S-parameters show excellent out-of-band rejection.