Table of Contents
How do I know what size antenna to get?
Basic calculation is the speed of light divided by the frequency. Say of an airband antenna to receive 125 MHz then it is 300/125 = 2.4 meters full wave length. Commonly, but not exclusively, antennas are either a ½ wave dipole hence 1.2 meters or a ¼ wave monopole hence 60cm in length.
What is antenna size related to?
The equation clearly shows that the higher the frequency, the shorter the wavelength, and the smaller the antenna.
How does the size of antenna depend upon frequency?
The lower the frequency, the larger the antenna should be to achieve the same gain. So, for a given link budget, the better the RF performance of the RF module, the smaller the antenna can be.
What factors determine the shape and configuration of a communication antenna?
Four main factors which differentiate antennas are frequency response, impedance, directivity, and electromagnetic polarization. When selecting an antenna for a particular application, these factors should be considered. In this section, these and other factors which influence antenna selection are discussed.
What size antenna is comparable?
size of antenna should be comparable to the wavelength of the signal.
Why are antennas different sizes?
The higher the wavelength, the longer the antenna needs to be to match it properly, and the wavelength is inversely proportional to the frequency. UHF frequencies have a shorter wavelength and therefore, the antenna can be shorter than for an equivalent VHF radio.
What is effect of increasing length of antenna?
Radio transmission efficiency generally increases with diameter and length of the conductor, but increased antenna length or weight can adversely affect animal behavior.
What is characteristics of antenna?
It is a fundamental property of antennas that the electrical characteristics of an antenna described in the next section, such as gain, radiation pattern, impedance, bandwidth, resonant frequency and polarization, are the same whether the antenna is transmitting or receiving.
What are the features of antenna?
Some of the characteristics of an antenna include the following.
- Radiation Pattern of Antenna.
- Polarization of Antenna.
- Intensity of Radiation.
- Effective Aperture.
- Gain & Directivity.
- Bandwidth.
- Power Gain & Radiation Efficiency.
- Effective Length.
How do you determine the size of an antenna?
Typically the size of an antenna is determined by the size of the wavelength being transmitted. Most metallic elements resonant when their physical is around [math]0.5\\lambda[/math], where [math]\\lambda[/math] is the wavelength.
Does antenna size affect gain and bandwidth?
(June 29, 1959) A theoretical analysis is made of the effect of antenna size on parameters such as gain, bandwidth, and efficiency. Both near-zone and far-zone directive gains are considered. It is found that the maximum gain obtainable from a broad-band antenna is approximately equal to that of the uniformly illuminated aperture.
What is the relationship between antenna gain and antenna effective aperture?
One basic antenna relationship presented below shows that antenna gain, g, and then antenna effective aperture (area) are directly proportional. This roughly indicates that antenna gain is proportional to the physical size of the antenna [2].
Why do antennas have different beam sizes?
When antennas are significantly larger than this, it is probably to get higher directivity or to better control the beam that is emitted. Wider beams diverge less, so they offer higher directivity. Wide beams can only come from wide antennas.
https://www.youtube.com/watch?v=oYDYuxX_rn0