Quarter-Wave Transformer
Transmission lines are used when the frequency of the electromagnetic signals is so high that the wave nature of the signals must be taken into account. A consequence of the wave nature is that the signals are reflected if there are abrupt changes of the characteristic impedance along the transmission line. Similarly, the load impedance, Z(L), at the end of the transmission line must match its ...
Circular Waveguide Filter
A circular waveguide filter is designed using a 2D axisymmetric model. Six annular rings added to the waveguide form circular cavities connected in series, and each cavity cutoff frequency is close to the center frequency of the filter. The simulated S-parameters show a bandpass frequency response.
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.
Designing a Waveguide Diplexer for the 5G Mobile Network
A diplexer is a device that combines or splits signals into two different frequency bands, widely used in mobile communication systems. This model simulates splitting properties using a simplified 2D geometry. The computed S-parameters and electric fields at the lower and upper bands will show the diplexer characteristics in the Ka-band.
Coupled-Line Bandpass Filter
It is possible to realize a narrowband bandpass filter using cascaded microstrip coupled lines. In this example, a design composed of cascaded microstrip lines, each approximately a half wave length in size at the resonant frequency, is analyzed. The model is solved for the S-parameters and a very narrow bandwidth is observed.
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 ...
Characteristic Parameters of a Coaxial Cable
Electrical cables, also called transmission lines, are used everywhere in the modern world to transmit both power and data. These cables carry electromagnetic energy, but instead of dealing with the full complexity of the electromagnetic fields, they are more commonly classified according to parameters such as capacitance, inductance, and impedance. In this model of a coaxial cable, we ...
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 ...
Radome with Double-layered Dielectric Lens
A radome minimizes losses and improves radiation characteristics of an antenna through its design. The structure can be optimized to minimize the transmission loss and also designed to improve radiation characteristics including antenna directivity and side lobes. Shown in the model is the surface current density on the patch antenna, the magnitude of the electric potential on the antenna's ...
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.
