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Guides
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- Evaluating EMF Compliance - Part 1: A Guide to Far-Field RF Exposure Assessments
- Design Guidelines for Skeleton Slot Antennas: A Simulation-Driven Approach
- Simplified Modeling for Microstrip Antennas on Ungrounded Dielectric Substrates: Accuracy Meets Simplicity
- Fast Modeling of a Monopole Supported by a Broadcast Tower
- Linking Log-Periodic Antenna Elements Using Transmission Lines
- Wave Matching Coefficient: Defining the Practical Near-Far Field Boundary
- AN-SOF Mastery: Adding Elevated Radials Quickly
- How to Merge Projects
- On the Modeling of Radio Masts
- The Equivalent Circuit of a Balun
- AN-SOF Antenna Simulation Best Practices: Checking and Correcting Model Errors
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- AN-SOF Antenna Simulation Software - Version 8.90 Release Notes
- AN-SOF 8.70: Enhancing Your Antenna Design Journey
- Introducing AN-SOF 8.50: Enhanced Antenna Design & Simulation Software
- Get Ready for the Next Level of Antenna Design: AN-SOF 8.50 is Coming Soon!
- Explore the Cutting-Edge World of AN-SOF Antenna Simulation Software!
- Upgrade to AN-SOF 8.20 - Unleash Your Potential
- AN-SOF 8: Elevating Antenna Simulation to the Next Level
- New Release: AN-SOF 7.90
- AN-SOF 7.80 is ready!
- New AN-SOF User Guide
- New Release: AN-SOF 7.50
- AN-SOF 7.20 is ready!
- New Release :: AN-SOF 7.10 ::
- AN-SOF 7.0 is Here!
- New Release :: AN-SOF 6.40 ::
- New Release :: AN-SOF 6.20 ::
- Show All Articles ( 1 ) Collapse Articles
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Models
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- Modeling a J-Fed 5-Element Collinear Antenna for the 2 m Band
- Simulating the Ingenious Multiband Omnidirectional Dipole Antenna Design
- The Loop on Ground (LoG): A Compact Receiving Antenna with Directional Capabilities
- Precision Simulations with AN-SOF for Magnetic Loop Antennas
- Advantages of AN-SOF for Simulating 433 MHz Spring Helical Antennas for ISM & LoRa Applications
- Radio Mast Above Wire Screen
- Square Loop Antenna
- Receiving Loop Antenna
- Monopole Above Earth Ground
- Top-Loaded Short Monopole
- Half-Wave Dipole
- Folded Dipole
- Dipole Antenna
- The 5-in-1 J-Pole Antenna Solution for Multiband Communications
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- Extended Double Zepp (EDZ): A Phased Array Solution for Directional Antenna Applications
- Transmission Line Feeding for Antennas: The Four-Square Array
- Log-Periodic Christmas Tree
- Enhancing VHF Performance: The Dual Reflector Moxon Antenna for 145 MHz
- Biquad UHF Antenna Array
- 145 MHz 5-Element Array of Square Loops
- Broadside Dipole Array
- Log-Periodic Dipole Array
- Broadband Directional Antenna
- A Closer Look at the HF Skeleton Slot Antenna
- The 17m Band 2-Element Delta Loop Beam: A Compact, High-Gain Antenna for DX Enthusiasts
- Enhancing Satellite Links: The Moxon-Yagi Dual Band VHF/UHF Antenna
- Array of Snowflake Quads
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Validation
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- Simple Dual Band Vertical Dipole for the 2m and 70cm Bands
- Linear Antenna Theory: Historical Approximations and Numerical Validation
- Validating Panel RBS Antenna with Dipole Radiators against IEC 62232
- Directivity of V Antennas
- Enhanced Methodology for Monopoles Above Radial Wire Ground Screens
- Dipole Gain and Radiation Resistance
- Convergence of the Dipole Input Impedance
- Impedance of Cylindrical Antennas
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The Method of Moments (MoM) is a technique used to convert the EFIE into a system of linear equations that then can be solved by standard methods. For simplicity, the integral (linear) operator in the Electric Field Integral Equation > (EFIE) will be denoted by L. Then, the EFIE takes the form:
where ET is the tangential component of the incident electric field. The current distribution is approximated by a sum of N basis functions with unknown amplitudes In, giving:
With this expansion and using the linearity of the operator L, we can write:
To obtain a set of N equations, the functional equation (3) is weighted with a set of N independent testing functions wm, giving:
where the integrals are calculated over the domain of L. Now we have as many independent equations as unknowns, so (4) can be written as:
where
[Z]: impedance matrix with dimension NxN and the elements
[I]: current matrix with dimension Nx1 and the elements In.
[U]: voltage matrix with dimension Nx1 and the elements
This fully occupied equation system must be solved for the unknown currents In. LU decomposition is used in AN-SOF. The MoM is applied by first dividing the wire structure into N segments, and then defining the basis and testing functions on the segments. Triangular basis and pulse testing functions are used in AN-SOF, Fig. 1.
When a curved wire is described parametrically by a vector function as in Eq. (5) here >, the basis and testing functions are curved in the sense that their support is a curved subset of the wire. Therefore, when curved basis and testing functions are used, the Conformal Method of Moments (CMoM) is obtained.
To fill the impedance matrix [Z], an adaptive Gauss-Legendre quadrature rule is applied to compute the involved integrals. After having solved the equation system, the currents In are known and other parameters of interest, such as input impedances, voltages, radiated power, directivity, and gain can be computed.
The MoM can also be used to calculate the electromagnetic response of metallic surfaces, which are modeled using wire grids. In AN-SOF, with the CMoM the accuracy of the calculation of wire grids is remarkably improved compared to the traditional MoM, as demonstrated in this article > . Another extension of the calculation includes wires that do not have a circular cross section. In AN-SOF an equivalent radius is calculated for these wires.