Cross Spiral Antenna (CSA)

This white paper presents a design and simulation of a Cross Spiral Antenna. The antenna model is as in the paper “A multi-polarization multi-band cross spiral antenna for  mobile communication devices”, ISAP 2012 International Symposium.

The CSA antenna exhibits good performances at 3 frequency bands so it is supposed to be used as combined RFID, mobile-phone (UMTS) and GPS band device – 1.0 GHz, 1.8 GHz and 1.67 GHz, respectively. This printed device is manufactured at low cost FR4 substrate with Er = 4.4 and Hsub = 1.6 mm.

Feeding area of the structure was done in two completely different ways. One was via a very simple wire bridge. The second feed area included coaxial feeders and connector with all the details. Despite that, results are very stable and similar. The configuration used for simulations is a standard desktop PC, while the simulation time is measured in seconds. The good agreement with measured results is also presented.

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Various Lens Types

Three designs of lens antennas with different lens types will be presented in this document. Such antennas with lenses can be used in real-life radar applications.

The first scenario assumes that the first illuminated surface of the lens (closer to the horn antenna) is hyperbolic while the second is flat (farther from the horn antenna). Similarly the remaining two scenarios are plane-convex and concave-convex.

All calculations are extremely efficient due to usage of Method of Moments (MoM) with unique higher order basis functions. The mesh elements can be 2 wavelengths large. WIPL-D built-in reflector object is customized to yield minimum simulation requirements for large apertures. The accuracy is controlled simply by adjusting number of segments. Simulations are prompt and results are tested for perfect convergence in only a few quick runs on a regular desktop or laptop. All the simulations last only a couple of seconds.

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Discone Antenna

In this application note, four models of the discone antenna are simulated as demonstration. The aim is to get close to the real-life problems where discone antennas operate in real-life environment. Here, the dielectric support, radome covering the antenna, losses in materials and frequency depended characteristics of used dielectric materials are taken into account.

All models will be created using WIPL‑D Pro CAD, a CAD modeler which includes Boolean operations. This approach is used since the antenna requires complicated dielectric mast, pedestal and radome, all intersecting each other.

Discone antenna is a wide band structure, simulated very fast and accurately by using WIPL-D. WIPL-D is Method of Moments (MoM) code based on Surface Integral Equations (SIE). Owing to efficient execution on multi-core CPUs, using symmetry, built-in interpolation, the tool simulates UWB antenna at regular desktop PC (0.5 GHz to 10.5 GHz band in 55 frequency points).

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Corrugated Horn in WIPL-D Pro Software

In this application note we compared simulated radiation pattern results for circular horn antenna and corresponding corrugated horn antenna. Also, we shortly outlined basic modelling of corrugated horn antenna with radial corrugations using WIPL-D Pro built-in object Body of Connected Generatrices.

All the simulations with the modelling were carried out using WIPL-D Software, a full wave 3D electromagnetic Method-of-Moments based software which applies Surface Integral Equations.

It was highlighted that corrugated horn antenna can be created efficiently combining WIPL-D Pro built-in object Body of Connected Generatrices and WIPL-D symbolic mechanism. The results clearly show that with corrugated horn antenna the level of back lobes is significantly lower. All of the simulations were carried out with high numerical efficiency resulting in short simulation times even when a standard workstation is used for simulation.

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Frequency Dependent Parameters in EM Simulation – Changing Dielectric Constant and Loss Tangent with Operating Frequency

The document demonstrates how to introduce frequency dependent dielectric parameters in WIPL-D Pro, a full-wave 3D EM simulator. Most materials used in fabrication of microwave circuits and antennas have frequency dependent properties which should be taken into account in EM simulations if accurate prediction of the device performance is important. This becomes extremely important when simulations are expected to produce high fidelity results which should serve as a benchmark in validating simulations against the measurements.

Modelling and simulation of a simple patch antenna from 1 GHz to 7 GHz is described. Simulation in such a wide frequency band are completed in around one minute even when using a standard, ‘everyday’ workstation, confirming once again high efficiency of WIPL D software.

In this particular case relative dielectric constant and loss tangent change with frequency, but in principle frequency dependency can be attributed to any symbolically defined parameter such as length, radius, etc. Dependency on frequency for several parameters can be handled using tabulated data stored in a project file.

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Compact Dual-Band Fork Monopole

We illustrate the advantages of WIPL‑D Pro by using simulation of a simple printed fork-shaped dual-band antenna for Bluetooth and general UWB applications.

For the simulation of printed patch antennas and circuits, a simple usage of WIPL-D features, such as Symmetry planes and Manipulation Edging, yields very fast and accurate solution. WIPL-D efficient simulation on multicore CPUs allows simulation in seconds at inexpensive desktop and laptop PCs. This eliminates the need for the high-end hardware platforms in order to simulate electrically small and moderate structures, even in wide frequency band.

The application note also shows the importance of the feeding are in simulation of the printed models, where most often we have transition between several guide wave technologies (in this case, the transition from coaxial to microstrip).

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Vivaldi Antenna

Vivaldi antenna is a commonly used antenna in broadband applications. As in this case, it is usually printed at the dielectric substrate. The simulation results show extremely wide band (return loss under -10 dB).

The simulation is performed in low number of frequency points due to the powerful built-in interpolation method (typically drawback of using MoM in simulation of UWB antennas since each frequency point is simulated separately).

In MoM, the simulation is quite fast at the lowest operating frequency, but more demanding at the end of the frequency band. WIPL-D offers built-in features where each frequency point is simulated according to the current simulation frequency. In that sense, the overall simulation time in a wide frequency band is decreased several times. Here, the simulation is performed by using a regular desktop quad core CPU and lasts couple of seconds per frequency point.

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Hyperboloid Lens Antenna Design Guide

This paper presents the procedure for the design of hyperboloid lens antenna. It contains theoretical consideration and foundation, as well as procedure for design in the WIPL-D software suite.

Hyperboloid Lens antenna consists of two parts: feeding cylindrical waveguide and the dielectric lens. Thus, the design procedure is approximately divided into two steps corresponding to the design of single part.

Finally, the app note shows WIPL-D Pro model at 25.5 GHz, its radiation pattern and the simulation details. Simulation is carried out in seconds at inexpensive every day PC.

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Microstrip Patch Antenna [Verification by Measurement]

Microstrip patch antennas are among the most popular antennas, used in various application areas. Modelling of such antennas is typically straight forward and can be done in WIPL-D general-purpose 3D modeler WIPL-D Pro. More advanced geometries or geometries provided by CAD file can be made simulation ready in AW Modeler or WIPL-D Pro CAD. A simple microstrip patch antenna is simulated.

The simulation itself is not of much relevance here. Simple printed antennas are simulated in WIPL-D at regular desktop or laptop PC in seconds. The application note was focused to verify the simulated results by using measurements performed by WIPL-D team

The software predicted the resonance at 1.905 GHz, while measurements pointed to 1.906 GHz. The simulated bandwidth is 19.35 MHz while the measured one is 19.3 MHz. The relative discrepancy is 0.05 % for resonant frequency and 0.25 % for bandwidth.

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