Antenna Design

Sinuous Antenna

This note presents the design of a sinuous antenna, which is often required in wideband airborne and communication applications. At low frequencies, the outer rings resonate, while at high frequencies the inner rings are resonant. At microwave frequencies, coaxial cable (unbalanced waveguide) is the most commonly used feeder. A balun transforms the input signal from unbalanced to balanced. A printed balun (microstrip technology) is placed below the planar sinuous antenna. Two baluns, Exponential and Klopfenstein taper, are analyzed, yielding return loss under -10 dB across an extremely wide band. EM simulations were carried out on a regular desktop computer at only 16 frequency points, thanks to built-in interpolation, with simulation times measured in seconds.

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Various Lens Types

Three designs of lens antennas with different lens types are presented, suitable for real-life radar, satellite, and advanced communication applications. The first scenario assumes the lens surface closer to the horn is hyperbolic and the far surface is flat; the other two scenarios are plane-convex and concave-convex. Calculations are efficient due to the Method of Moments (MoM) with higher-order basis functions, allowing mesh elements up to 2 wavelengths. WIPL-D’s built-in reflector object minimizes simulation requirements for large apertures. Accuracy is controlled via segment adjustment, and all simulations converge quickly within a few runs on a standard desktop or laptop, lasting only a couple of seconds, showing robust performance.

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Corrugated Horn in WIPL-D Pro Software

In this application note, we compared simulated radiation patterns for a circular horn antenna and corresponding corrugated horn antenna using
WIPL-D Pro’s built-in object Body of Connected Generatrices. All simulations were carried out with WIPL-D, a full-wave 3D EM MoM solver based on Surface Integral Equations. The corrugated horn antenna can be efficiently created by combining the Body of Connected Generatrices object with WIPL-D symbolic mechanisms. Results show back-lobe levels are significantly reduced. Simulations were performed with high numerical efficiency, resulting in short simulation times even on a standard desktop workstation, demonstrating WIPL-D’s overall robust capabilities for complex antenna designs.

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Discone Antenna

In this note, four models of the discone antenna are simulated to demonstrate real-life operation. Dielectric support, radome covering, material losses, and frequency-dependent dielectric characteristics are all included for completeness and accuracy. All models are created using WIPL-D Pro CAD, which supports Boolean operations, necessary for modeling the complex mast, pedestal, and radome intersecting each other. The discone antenna is a wideband structure, simulated quickly and accurately using WIPL-D, a Method of Moments code based on Surface Integral Equations. Efficient execution on multicore CPUs, use of symmetry, and built-in interpolation allow simulation of the UWB antenna on a regular desktop PC.

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Frequency Effects on Dielectric Constant and Loss Tangent

This document demonstrates how to introduce frequency-dependent dielectric parameters in WIPL-D Pro, a full-wave 3D EM simulator. Most materials used in microwave circuits and antennas vary with frequency, which must be carefully considered in EM simulations to predict device performance accurately. This is crucial when simulations are expected to provide high-fidelity results for validation against measurements. A simple patch antenna from 1 GHz to 7 GHz is modeled and simulated, with results in about one minute on a standard workstation, confirming WIPL-D’s efficiency. Frequency dependency can apply to any symbolically defined parameter, such as length or radius, with multiple parameters handled via tabulated data in the project file.

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Cross Spiral Antenna (CSA)

This note presents the design and simulation of a Cross Spiral Antenna (CSA), a planar antenna, based on the paper “A multi-polarization multi-band cross spiral antenna for mobile communication devices”, ISAP 2012. The CSA exhibits good performance at three frequency bands, intended for combined RFID, mobile-phone (UMTS), and GPS applications at 1.0 GHz, 1.8 GHz, and 1.67 GHz, respectively. The printed device is fabricated on low-cost FR4 substrate (Er = 4.4, Hsub = 1.6 mm). The feeding area was realized in two ways: a simple wire bridge and a coaxial feed with connector. Both approaches yielded stable, similar results. Simulations were performed on a standard desktop PC, with times measured in seconds, showing agreement with measured data.

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Compact Dual-Band Fork Monopole

This paper illustrates the advantages of WIPL-D Pro by simulating a simple printed fork-shaped dual-band antenna for Bluetooth and general UWB applications. For printed patch antennas and circuits, using WIPL-D features such as Symmetry planes and Manipulation Edging yields fast, accurate solutions. Efficient simulation on multicore CPUs allows execution in seconds on inexpensive desktop and laptop PCs, eliminating the need for high-end hardware even for electrically small or moderate structures in wide frequency bands. The application note also highlights the importance of the feeding area in printed models, where transitions between several guided-wave technologies, such as coaxial to microstrip in this case, are critical for accurate simulation.

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Hyperboloid Lens Antenna Design Guide

The model of a hyperboloidal lens illuminated by a choke horn antenna was successfully designed and simulated using WIPL-D Pro software. The modeling process includes usage of WIPL-D Pro built-in objects, ensuring an optimal number of unknowns, which simplifies the modeling process and significantly speeds up the simulations. The radiation pattern of the free-space choke horn was compared to that of the lens antenna, clearly demonstrating the focusing effect. This effect is further illustrated by calculating the near field both in front of and behind the lens. All simulations were carried out in just a few seconds on an inexpensive desktop PC, showing the efficiency, speed, and accuracy of the software for practical lens antenna design.

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Microstrip Patch Antenna [Verification by Measurement]

Microstrip patch antennas are among the most popular types, used in various applications. Modeling is typically straightforward and can be done in WIPL-D 3D modeler, WIPL-D Pro. More complex geometries or CAD designs can be prepared in WIPL-D Pro CAD or AW Modeler. A simple microstrip patch antenna is simulated. The simulation itself is not primary, as printed antennas run in seconds on a desktop or laptop. The application note focuses on verifying simulation results with measurements by the WIPL-D team. The software predicted resonance at 1.905 GHz, while measurements indicated 1.906 GHz. The simulated bandwidth is 19.35 MHz, with measured 19.3 MHz, giving a relative discrepancy of 0.05 % for resonant frequency and 0.25 % for bandwidth.

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Printed Monopole Antenna for 5G Network Frequency Bands

This note presents the analysis of an antenna operating in 5G network frequency bands using WIPL-D Software. S-parameters and radiation patterns of a printed monopole antenna fed with a coplanar waveguide were calculated and carefully compared. All simulations and modeling were performed using WIPL-D, a full-wave 3D electromagnetic Method-of-Moments solver based on Surface Integral Equations. Simulations are fast, accurate, and agree well with referenced results. The note clearly demonstrates how a planar structure can be built with minimal effort in WIPL-D Pro CAD, including realistic antenna connections modeled with three different feeders, achieving high numerical efficiency and very short simulation times even on a laptop.

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Helix Antennas

Discovered by scientist Krauss in 1946, helix antenna is used in space applications, radar systems, and more. It is usually manufactured as a wire coiled around a dielectric cylinder, producing circular polarization of the emitted EM wave. This application note compares simulation times, number of unknowns, and radiation patterns for three simulated helix antennas: wire helix, thin strip helix, and thin strip with dielectric mast. In WIPL-D software, various helix antennas can be efficiently designed using the powerful built-in Helix object. Simulations were carried out on a regular desktop PC with extremely low number of unknowns and times measured in seconds, allowing fast tuning, sweep, or optimization of the antenna for engineering.

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Spiral Antennas

In this note, we analyze two spiral antennas, one with an air substrate and the other with a dielectric substrate between spiral arms and metallic reflector. In WIPL-D Pro, a spiral can be easily created and modified using the built-in flexible Helix object. Especially when the same mesh over close surfaces is required (antenna reflector and spiral arms), the built-in Copy\Layer manipulation is very useful and simplifies model setup significantly. The antennas are simulated from 0.3 GHz to 6 GHz in a wide frequency band. Number of frequencies is reduced using logarithmic scale and built-in interpolation. Simulation was carried out on a regular desktop PC with low number of unknowns, and simulation times measured in seconds, showcasing efficiency.

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