# Theory and experiment of antenna

## Principle of operation and example of antenna

The high-frequency current which is a kind of the exchange electricity flows and the antenna works. Because electricity is not visible, I do not understand anything only from seeing. If the theory of electricity and the high frequency cannot be understood to some degree, it becomes double Dutch about the antenna.

Even if it is not so understood, the theory can stretch an antenna by the experience when the antenna is actually handled. If anyway the same antenna is put up, it is needless to say to should set it up by you after understanding the theory.

It is likely not to operate well when setting it up without knowing the antenna at all though there is the amateur's putting up the terrestrial digital broadcasting antenna. Even if a little trouble is found in the receiving antenna, danger of becoming a fire will not be electrical work. It would be greatly appreciated when this page serves as a reference to understand the antenna.

This figure is figure where the movement of the dipole aerial was shown. The dipole aerial is a fundamental form of all antennas. First of all, I will understand this.

The voltage in the element of 1/2 wavelength dipole antenna becomes the maximum in both ends, and the current becomes 0 earlier than it because it doesn't flow. Moreover, the voltage generally becomes in the feeding point and the currents become maximums lowest.

This operation is basic of the tune type antenna. Similarly, it becomes 0 in the current in the maximum voltage in the point in the dipole aerial of one wavelength. It will feed power from the point of the maximum voltage and the lowest current, and the device is necessary for feeding power if it feeds power from the center.

It is thought that there is the lower half of the vertical dipole antenna of λ/2 under the soil for the vertical earth antenna of λ/4. In this case, the ground resistance influences efficiency.

## Chance and purpose to make this HP

Because the page concerning the antenna has increased on the page of the device and production, this decided to be made to be become independent and to assume another page. It will be ..information.. ..Mitsuru truth.. [se] concerning the ground digital antenna when the future.

Please do by the self-responsibility safely carefully when the antenna is constructed for myself. Please stop it if not confident.