Using the Numeric Port feature, available in the COMSOL Multiphysics® software with the add-on RF Module, the mode of a port with an arbitrary shape can be computed numerically via a boundary mode analysis. By adding a Frequency Domain or an Adaptive Frequency Sweep study, the S-Parameter and Smith plots can be obtained. The numeric port also enables us to calculate the characteristic impedance of transmission lines operating in the transverse electromagnetic (TEM) mode.

With the rise of 5G and other wireless millimeter-wave applications, there has been an increase in front-end antenna solutions that depend on monopole, dipole, and patch antennas. In these devices, the radiation efficiency tends to suffer due to the effect of lossy silicon substrate materials. Enter the dielectric resonator: Antennas using these resonators (made of nonmetallic materials) have a higher radiation efficiency. To increase directivity and gain at high frequencies, engineers can optimize dielectric resonator antenna (DRA) designs with simulation.

Thanks to their ability to “tune out” specific frequencies, electromagnetic band gaps (EBGs) are found in many different applications. EBGs can suppress unwanted electromagnetic interference (EMI) and increase electromagnetic compatibility (EMC). These structures are commonly used between nearby antennas, which can help minimize undesirable coupling and thereby enhance their performance. However, using an EBG isn’t always a guarantee for better antenna isolation. To analyze the effectiveness of an EBG, engineers can use the COMSOL Multiphysics® software and add-on RF Module.

When it comes to advancements in healthcare, we have a lot to be thankful for. Because of anesthesia, patients no longer need to “bite the bullet” during surgery. Thanks to antibiotics, doctors don’t use bloodletting to cure an infection. Moving into more modern times, radio-frequency identification (RFID) systems offer a wide variety of innovative healthcare applications. However, like any new medical technology, biomedical RFID devices must be rigorously evaluated for performance and compatibility with other medical systems.

Since high-speed communication is inevitable for evolving wireless systems, the demand for a higher data rate, higher frequency, larger spectrum, and wider bandwidth increases. When dealing with a wide bandwidth, multiple devices may have to be deployed in a wireless communication system to filter out unwanted noise and interfering signals, enhance the signal-to-noise ratio, and improve the sensitivity. A single tunable filter can replace these devices, reducing the system’s size and weight and the fabrication cost of multiple components.

When we analyze high-frequency electromagnetics problems using the finite element method (FEM), we often compute S-parameters in the frequency domain without reviewing the results in the complementary domain; that is, the time domain. The time domain is where we can find other useful information, such as time-domain reflectometry (TDR). In this blog post, we will demonstrate data conversion between two domains in order to efficiently obtain results in the desired computation domain through a fast Fourier transform (FFT) process.

Circulators are a bit like traffic circles (also known as rotaries or roundabouts), where motion occurs in one direction only and each pathway doubles as an entrance and exit. In a circulator, however, the microwave signal always exits at the next available port. This characteristic makes circulators useful for applications that involve coupling transmitters and receivers to common antennas. To ensure that circulators function successfully, electrical engineers can study their designs with electromagnetics simulation.

Many antennas deployed in basic communications systems are linearly polarized, meaning that for the orientation of the electric field, polarization is confined to a single plane. Antennas that present the option of circular polarization give you more to work with, because the polarization of the wave varies while it propagates. Helical antennas, for instance, are able to generate circularly polarized waves in the axial operating mode. RF simulation can be used to optimize helical antenna designs.

Since their development in the 1960s, subminiature version A (SMA) connectors have become a staple in the RF and microwave industries. The use of these connectors is so widespread, they might even be the most popular RF and microwave connector systems on Earth. To evaluate the performance of an SMA connector, engineers can use the COMSOL Multiphysics® software.

Due to their inherent versatility and wideband frequency response, spiral slot antennas have a variety of applications for different microwave frequency bands. For example, these antennas are used for wireless communication, sensing, positioning, and tracking. To optimize the design of spiral slot antennas, engineers can use electromagnetics analysis to accurately calculate characteristics such as S-parameters and far-field patterns.