The optimization of components with respect to geometrical design parameters is a common task in microwave engineering. In this model the reflection coefficient of a waveguide structure is minimized, and the sensitivities of the real and...
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...
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...
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...
Coplanar waveguide (CPW) bandpass filters can be realized using interdigital capacitors (IDCs) and short-circuited stub inductors (SSIs). Such a filter can readily be implemented on a GaAs wafer. This presented model is very compact in...
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...
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...
Feeding antennas with proper signals can be difficult. The signal is often described as a voltage, and voltages are not well defined in electromagnetic wave formulations. There are several tricks to model voltage generators in such...
A voltage generator feeds a microstrip on a circuit board using an interior lumped port boundary condition. The model calculates the microstrip impedance and compares two terminations; a numerical port using boundary-mode analysis, and...
A bird-cage coil is used in Magnetic Resonance Imaging (MRI) applications as a receiving antenna. This particular coil would sit around limbs and be used to scan a leg or arm. The COMSOL Multiphysics with RF Module model...
