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Guides
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- Modeling Common-Mode Currents in Coaxial Cables: A Hybrid Approach
- Evaluating EMF Compliance - Part 2: Using Near-Field Calculations to Determine Exclusion Zones
- Beyond Analytical Formulas: Accurate Coil Inductance Calculation with AN-SOF
- Complete Workflow: Modeling, Feeding, and Tuning a 20m Band Dipole Antenna
- DIY Helix High Gain Directional Antenna: From Simulation to 3D Printing
- 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
- Enhancing Antenna Design: Project Merging in AN-SOF
- On the Modeling of Radio Masts
- RF Techniques: Implicit Modeling and Equivalent Circuits for Baluns
- AN-SOF Antenna Simulation Best Practices: Checking and Correcting Model Errors
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- To Our Valued AN-SOF Customers and Users: Reflections, Milestones, and Future Plans
- AN-SOF 9.50 Release: Streamlining Polarization, Geometry, and EMF Calculations
- AN-SOF 9: Taking Antenna Design Further with New Feeder and Tuner Calculators
- 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 (4) Collapse Articles
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Models
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- Download Examples
- Explore 5 Antenna Models with Less Than 50 Segments in AN-SOF Trial Version
- Modeling a Center-Fed Cylindrical Antenna with AN-SOF
- Modeling a Circular Loop Antenna in AN-SOF: A Step-by-Step Guide
- Monopole Over Real Ground
- Helix Antenna in Axial Mode
- Yagi-Uda Array
- A Transmission Line
- An RLC Circuit
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- Modeling a Super J-Pole: A Look Inside a 5-Element Collinear Antenna
- Simulating the Ingenious Multiband Omnidirectional Dipole Antenna Design
- The Loop on Ground (LoG) Antenna: A Compact Solution for Directional Reception
- 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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- The Lazy-H Antenna: A 10-Meter Band Design Guide
- 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
- Building a Compact High-Performance UHF Array with AN-SOF: A 4-Element Biquad Design
- Building a Beam: Modeling a 5-Element 2m Band Quad Array
- 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
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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
- Validating V Antennas: Directivity Analysis with AN-SOF
- Enhanced Methodology for Monopoles Above Radial Wire Ground Screens
- Dipole Gain and Radiation Resistance
- Convergence of the Dipole Input Impedance
- Validating Dipole Antenna Simulations: A Comparative Study with King-Middleton
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Enhancing Satellite Links: The Moxon-Yagi Dual Band VHF/UHF Antenna
In amateur radio satellite communication, the use of directional antennas is a fundamental necessity. Operating on both the VHF and UHF bands with a single antenna can present a considerable challenge. In this article, we introduce a dual-band antenna design that covers both VHF and UHF bands, accomplished by combining two distinct antenna types: the Moxon antenna for VHF frequencies and the Yagi antenna for UHF frequencies. One of the notable advantages of this design is that it utilizes a single feeding point.
The Moxon antenna, also known as the Moxon rectangle, stands as a simple yet mechanically robust antenna configuration composed of two elements: a driven element and a parasitic element. It derives its name from the renowned radio amateur, Les Moxon, with the call sign G6XN. In essence, the Moxon antenna resembles a Yagi-Uda antenna with two folded dipole elements, one serving as the driven element and the other as the reflector element. A tunable gap exists between these two folded dipoles, allowing for adjustments to minimize the VSWR (Voltage Standing Wave Ratio) at VHF frequencies. Consequently, it is a mechanically tunable antenna that eliminates the need for an impedance matching network. In our dual-band design, as illustrated below, the Moxon segment of the antenna serves as the excitation point.
The accompanying figure also depicts the Yagi-Uda portion of the dual antenna. This section adheres to the conventional Yagi array configuration, comprising a reflector element, a driven element, and three directors. However, the driven element in this context does not receive direct excitation; instead, it is powered indirectly through electromagnetic induction from the driven element of the Moxon array. The gap separating the Moxon and Yagi sections of the combined antenna can be mechanically adjusted to minimize the VSWR at UHF frequencies.
In the analyzed frequency ranges, this VHF/UHF dual-band antenna exhibits self-resonance with an input impedance close to 50 Ohms, obviating the requirement for a matching network. To optimize performance in each band, fine-tune the gaps as indicated in the figure below.
Additionally, the figure provides VSWR curves as a function of frequency. In the upper section, it is evident that the antenna resonates at 147 MHz, while in the lower section, it resonates at 442 MHz. The figure also presents radiation patterns for both frequency bands, with gains of 6.3 dBi at VHF and 12 dBi at UHF.
Detailed AN-SOF models, along with antenna dimensions and calculations, are available for download through the buttons located below the figure.