Antenna Mini-square. Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / VHF antennas
Comments on the article
Max Blumer (WA1MKP) proposed an antenna designed by him that occupies a minimum of space. The antenna is a loop with a perimeter equal to the wavelength.
The figure explains the intention of the antenna designer. As a basis, a regular frame (left sketch) was taken, fed at points x and y. This frame radiates a vertically polarized wave in two directions perpendicular to the plane of the drawing, the maximum field strength is in the plane A-A'. The frame can be turned into a square, then (without significant loss of efficiency) into a rectangle (middle thumbnail). In this case, the polarization of the wave and the directivity of the radiation will be the same as those of the round frame. If this rectangle is bent 90° first along the lines A-A', and then along the lines B-B' and C-C', the flat loop will turn into a three-dimensional cube (right sketch). The perimeter of the antenna, of course, will be equal to the wavelength (L), and each side of the cube will be only 1/10L.
In this case, the vertical polarization of the emitted wave will be preserved, and instead of a bidirectional radiation pattern, an almost omnidirectional pattern will be obtained.
The stated principle was first implemented in the form of a 144 MHz band antenna. A 50-ohm coaxial cable with a matching device was used for power supply (SWR varied from 1,2 to 1,4 over the range). A study of the radiation pattern using a field strength meter showed that there is a slight difference in the radiation forward-backward (1,8 dB) and forward-sideways (3 dB), the latter was apparently due to the shielding effect of the supply cable and structural elements.
Then WA1MKP made a similar antenna for the 21 MHz band. It had the same characteristics (however, the SWR turned out to be slightly higher). In addition to QSOs with other US states, contacts were made with South America and Europe.
Author: Max Blumer; Publication: N. Bolshakov, rf.atnn.ru
See other articles Section VHF antennas.
Read and write useful comments on this article.
<< Back
Latest news of science and technology, new electronics:
A New Way to Control and Manipulate Optical Signals
05.05.2024
The modern world of science and technology is developing rapidly, and every day new methods and technologies appear that open up new prospects for us in various fields. One such innovation is the development by German scientists of a new way to control optical signals, which could lead to significant progress in the field of photonics. Recent research has allowed German scientists to create a tunable waveplate inside a fused silica waveguide. This method, based on the use of a liquid crystal layer, allows one to effectively change the polarization of light passing through a waveguide. This technological breakthrough opens up new prospects for the development of compact and efficient photonic devices capable of processing large volumes of data. The electro-optical control of polarization provided by the new method could provide the basis for a new class of integrated photonic devices. This opens up great opportunities for ... >>
Primium Seneca keyboard
05.05.2024
Keyboards are an integral part of our daily computer work. However, one of the main problems that users face is noise, especially in the case of premium models. But with the new Seneca keyboard from Norbauer & Co, that may change. Seneca is not just a keyboard, it is the result of five years of development work to create the ideal device. Every aspect of this keyboard, from acoustic properties to mechanical characteristics, has been carefully considered and balanced. One of the key features of Seneca is its silent stabilizers, which solve the noise problem common to many keyboards. In addition, the keyboard supports various key widths, making it convenient for any user. Although Seneca is not yet available for purchase, it is scheduled for release in late summer. Norbauer & Co's Seneca represents new standards in keyboard design. Her ... >>
The world's tallest astronomical observatory opened
04.05.2024
Exploring space and its mysteries is a task that attracts the attention of astronomers from all over the world. In the fresh air of the high mountains, far from city light pollution, the stars and planets reveal their secrets with greater clarity. A new page is opening in the history of astronomy with the opening of the world's highest astronomical observatory - the Atacama Observatory of the University of Tokyo. The Atacama Observatory, located at an altitude of 5640 meters above sea level, opens up new opportunities for astronomers in the study of space. This site has become the highest location for a ground-based telescope, providing researchers with a unique tool for studying infrared waves in the Universe. Although the high altitude location provides clearer skies and less interference from the atmosphere, building an observatory on a high mountain poses enormous difficulties and challenges. However, despite the difficulties, the new observatory opens up broad research prospects for astronomers. ... >>
| Random news from the Archive Wireless communication for mobile phone
29.01.2001
The Japanese company Total Design Communications has developed a wireless headset for mobile phones called "i2me". Using the new Bluetooth technology, it provides a stable connection between the earphone and the "mobile phone" at a distance of up to 10 meters.
Thus, nothing prevents now to put the phone in a bag and forget about it until the incoming call. Then, without getting confused in the wires, "pick up the phone" and start a conversation. And to do this is surprisingly simple: the device controls are limited to the answer button and the volume control.
The new headset is powered by just one coin cell battery, which lasts for two weeks of intensive use. True, the price of new items is still too high - about $220.
|
Other interesting news:
▪ Tired of your own thoughts
▪ Apple's eye-tracking 3D interface
▪ Netbook Samsung N310
▪ Rear view mirror with touchscreen and LTE
▪ Lunar Vacuum Cleaner
News feed of science and technology, new electronics
Interesting materials of the Free Technical Library:
▪ site section Lightning protection. Article selection
▪ article Architecture - frozen music. Popular expression
▪ article What is the healthiest fat? Detailed answer
▪ article Operator of electronic typesetting and layout on a personal computer (PC). Standard instruction on labor protection
▪ article Economical electronic cat. Encyclopedia of radio electronics and electrical engineering
▪ article The mysterious disappearance of a ring from a rope. Focus secret
Leave your comment on this article:
All languages of this page
Home page | Library | Articles | Website map | Site Reviews
www.diagram.com.ua
2000-2024
Arabic
Bengali
Chinese
English
French
German
Hebrew
Hindi
Italian
Japanese
Korean
Malay
Polish
Portuguese
Spanish
Turkish
Ukrainian
Vietnamese