1. What is Antenna Beamwidth?

Antenna beamwidth refers to the angular width of the main lobe of the antenna radiation pattern. It represents the angle between the half-power (-3 dB) points of the main lobe, measured in degrees. A narrower beamwidth indicates a more directional antenna with higher gain.

2. How Does the Calculator Work?

The calculator uses the beamwidth formula:

Where:

• \( Wavelength \) — Wavelength of the signal (meters)
• \( Diameter \) — Diameter of the antenna aperture (meters)

Explanation: This formula provides an approximation of the half-power beamwidth for parabolic antennas. The constant 70 is derived from empirical measurements and varies slightly depending on the antenna design and illumination taper.

3. Importance of Beamwidth Calculation

Details: Beamwidth calculation is crucial for antenna design, satellite communication, radar systems, and wireless networks. It helps determine the antenna's directivity, coverage area, and ability to focus energy in specific directions.

4. Using the Calculator

Tips: Enter wavelength and diameter in meters. Both values must be positive numbers. The calculator will compute the beamwidth in degrees.

5. Frequently Asked Questions (FAQ)

Q1: What factors affect antenna beamwidth?
A: Beamwidth is primarily determined by antenna size relative to wavelength. Larger antennas (relative to wavelength) have narrower beamwidths.

Q2: How does beamwidth relate to antenna gain?
A: Narrower beamwidth generally corresponds to higher antenna gain, as energy is concentrated in a smaller angular area.

Q3: What is the difference between half-power beamwidth and first-null beamwidth?
A: Half-power beamwidth measures the angle between -3 dB points, while first-null beamwidth measures the angle between the first nulls on either side of the main lobe.

Q4: Can this formula be used for all antenna types?
A: This formula is specifically for parabolic reflector antennas. Other antenna types have different beamwidth characteristics.

Q5: How accurate is this approximation?
A: The formula provides a good approximation for most practical purposes, but actual beamwidth may vary based on specific antenna design and feed illumination.