Home
Back
5/8 Wave Vertical Antenna Length Formula:
| From: | To: |
The 5/8 wave vertical antenna is a popular antenna design that offers a good compromise between gain and radiation pattern. It provides approximately 3 dB gain over a quarter-wave antenna and has a lower radiation angle, making it effective for long-distance communications.
The calculator uses the 5/8 wave antenna length formula:
Where:
Explanation: The formula calculates the physical length of a 5/8 wavelength antenna based on the operating frequency and the speed of light.
Details: Accurate antenna length calculation is crucial for optimal antenna performance, proper impedance matching, and efficient radiation of RF energy. The 5/8 wavelength design offers improved gain and radiation characteristics compared to shorter antennas.
Tips: Enter the operating frequency in Hz (or use common units like MHz by multiplying by 1,000,000). The speed of light is pre-set to 300,000,000 m/s but can be adjusted if needed. All values must be positive numbers.
Q1: Why use a 5/8 wave antenna instead of 1/4 wave?
A: The 5/8 wave antenna provides approximately 3 dB more gain and a lower radiation angle, making it better for long-distance communications.
Q2: What is the radiation pattern of a 5/8 wave vertical?
A: It has a lower radiation angle compared to quarter-wave antennas, which concentrates more energy toward the horizon rather than straight up.
Q3: Does this calculator account for velocity factor?
A: No, this calculates the free-space length. For practical antennas, you may need to apply a velocity factor based on the antenna material.
Q4: What are typical applications for 5/8 wave antennas?
A: They are commonly used in base station antennas for amateur radio, commercial communications, and broadcast applications where improved gain is desired.
Q5: How do I match impedance for a 5/8 wave antenna?
A: 5/8 wave antennas typically require impedance matching, often using a coil or matching network, as their impedance is not 50 ohms like quarter-wave antennas.