Antenna Decoupling Using An Electromagnetic Band Gap Meta-Material
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 ...
Simulation of an Electromagnetic Sounding Method for Oil Prospecting
The marine controlled source electromagnetics method (CSEM) for oil prospecting has emerged as a promising technique during recent years. This model demonstrates one variant of it. It uses a mobile horizontal 1 Hz electric dipole antenna that is towed 150 m above the sea floor. An array of sea floor receivers measure the electric field at various distances away from the antenna. When measuring ...
Tunable Evanescent Mode Cavity Filter Using a Piezo Actuator
An evanescent mode cavity filter can be realized by adding a structure inside of the cavity. This structure changes the resonant frequency lower than the dominant mode of the unfilled cavity. A piezo actuator is used to control the size of a small air gap which provides the tunability of the resonant frequency.
Thermal Drift in a Microwave Cavity Filter
Microwave filters are used to eliminate unwanted frequency components in the output from microwave transmitters. They are typically inserted between a power amplifier and an antenna. The amplifiers are nonlinear and produce harmonics that must be eliminated with filters that have a rather narrow passband. Due to high power loads but also possibly from harsh environmental conditions (such as a ...
Modeling a Biconical Antenna for EMI/EMC Testing
Biconical antennas are popular for very high frequency (VHF) measurement because they support a wide frequency range. They are also useful for electromagnetic compatibility (EMC) testing where the antenna can be used as an RF source in susceptibility or immunity test. This model simulates a biconical antenna made of lightweight hexagonal frames that are preferred over solid cones for ...
Evanescent Mode Cylindrical Cavity Filter
An evanescent-mode cavity filter is resonant at a frequency lower than its original fundamental mode frequency. Evanescent mode resonance can be realized by creating a discontinuity or reactance inside the cavity. The basic model was modified by the addition of a metal box at either end representing a housing. Inside a dielectric substrate and a microstrip line coupled into the cavity. The ...
TM Mode Microwave Plasma
This model shows how to simulate a TM mode microwave plasma by using the Doppler broadening parameter to smooth out the resonance zone, which occurs on the contour of critical electron density. A detailed explanation of the underlying physics of this model can be found in the blog entry "Application Note on Microwave Discharges".
Rat-Race Coupler
A 180° Ring Hybrid (Rat-Race Coupler) is a four-port network with 180° phase difference between two ports. It is cheaper to manufacture this type of microstrip line component compared to a wave guide 180° hybrid junction, so called magic-T. The objective of this model is to compute the S-parameters and to observe the matching, isolation, and coupling around the operating frequency.
Fast Numerical Modeling of a Conical Horn Lens Antenna
An axisymmetric 3D structure such as a conical horn antenna can be simulated in a fast and efficient way using only its 2D layout. In this model, the antenna radiation and matching characteristics are computed very quickly with respect to the dominant TE mode from the given circular waveguide by simulating the 2D axisymmetric geometry of an 3D antenna structure.
Cascaded Rectangular Cavity Filter
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.
