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1/2 Wave Antenna Length Formula:
Where:
l = Antenna Length (meters)
c = Speed of Light = 3×10⁸ m/s
f = Frequency (Hz)
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A half-wave antenna is a basic resonant antenna whose length is approximately half the wavelength of the transmitted or received signal. It's one of the most common and efficient antenna designs for many applications.
The calculator uses the 1/2 wave antenna formula:
Where:
Explanation: The formula calculates the physical length needed for an antenna to resonate at a specific frequency, with the length being half the wavelength of the signal.
Details: Proper antenna length is crucial for optimal signal transmission and reception. A correctly sized antenna maximizes efficiency, minimizes standing wave ratio (SWR), and ensures proper impedance matching.
Tips: Enter the frequency in Hertz (Hz). For radio frequencies, you may need to convert from MHz or kHz (1 MHz = 1,000,000 Hz, 1 kHz = 1,000 Hz).
Q1: Why is a half-wave antenna commonly used?
A: Half-wave antennas offer a good balance between size and performance, with reasonable radiation resistance and relatively simple construction.
Q2: Does this calculation work for both transmitting and receiving antennas?
A: Yes, the length calculation is the same for both transmitting and receiving antennas operating at the same frequency.
Q3: Are there practical considerations that might affect the actual length?
A: Yes, factors like antenna material, surrounding environment, and end effects may require slight adjustments to the theoretical length.
Q4: Can I use this for different types of half-wave antennas?
A: This calculation provides the basic length for a center-fed dipole. Other half-wave variants (like end-fed) may require different calculations.
Q5: What's the relationship between wavelength and frequency?
A: Wavelength (λ) = speed of light (c) / frequency (f). A half-wave antenna is therefore λ/2 = c/(2f).