How to use the calculator
- Enter the distance from the beam source (in meters). This is the horizontal distance to the point where you want to measure the beam field angle.
- Enter the height of the beam source (in meters). This is the vertical distance from ground level to the beam source.
- Enter the beam width at the measurement distance (in meters). This is the width of the beam at the specified distance.
- Click the "Calculate" button to compute the field angle and half power angle.
Understanding the results
The calculator provides two key results:
- Field Angle (θ): The total angle between the center of the beam and the edges of the beam at the specified distance. This represents how wide the beam spreads at that distance.
- Half Power Angle (HPA): Also known as the 3dB beamwidth, this is the angle within which the beam has approximately half the power of the main lobe. It's commonly used in antenna specifications.
Principle of calculation
The calculator uses the simple geometric relationship between beam width, distance, and field angle. For a more accurate calculation, you would need to consider the beam divergence characteristics, but this calculator provides a good approximation for many common scenarios.
Applications
This calculator can be used in various fields including:
- Antenna design and placement
- Lighting engineering and luminaire selection
- RF signal propagation analysis
- Sound system coverage planning