Corkscrew (spiral) - antenna. Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / Television antennas
Comments on the article
The antenna is located horizontally and has a narrow radiation pattern. It is possible to build an array of several corkscrew antennas.
The metal plate is an antenna reflector, and not a counterweight, as it might seem at first glance.
A metal rod with a dielectric spacer gives the antenna mechanical strength. On satellite dishes, this rod has directors and a ten times longer spiral.
The antenna is designed to operate in the frequency range 814-960 MHz. It is easy to manufacture, has a solid construction and, like all helical antennas, has a circularly polarized wave.
Circular polarization provides the best transmission in urban areas. Apparently, the classical property of a corkscrew is fully manifested here.
This antenna is powered through a cable with a characteristic impedance of 75 ohms.
The resonant frequency is adjusted by compressing or stretching the turns of the antenna, and if the resonant frequency strongly deviates from the required one, by shortening the length of the conductor.
All parameters of helical antennas were obtained experimentally.
Spiral diameter - 100mm;
Number of turns - 7,5
Winding pitch - 30mm
Author: Vasily Vasilenko, Yakutsk; Publication: inspector_v.chat.ru
See other articles Section Television antennas.
Read and write useful comments on this article.
<< Back
Latest news of science and technology, new electronics:
Artificial leather for touch emulation
15.04.2024
In a modern technology world where distance is becoming increasingly commonplace, maintaining connection and a sense of closeness is important. Recent developments in artificial skin by German scientists from Saarland University represent a new era in virtual interactions. German researchers from Saarland University have developed ultra-thin films that can transmit the sensation of touch over a distance. This cutting-edge technology provides new opportunities for virtual communication, especially for those who find themselves far from their loved ones. The ultra-thin films developed by the researchers, just 50 micrometers thick, can be integrated into textiles and worn like a second skin. These films act as sensors that recognize tactile signals from mom or dad, and as actuators that transmit these movements to the baby. Parents' touch to the fabric activates sensors that react to pressure and deform the ultra-thin film. This ... >>
Petgugu Global cat litter
15.04.2024
Taking care of pets can often be a challenge, especially when it comes to keeping your home clean. A new interesting solution from the Petgugu Global startup has been presented, which will make life easier for cat owners and help them keep their home perfectly clean and tidy. Startup Petgugu Global has unveiled a unique cat toilet that can automatically flush feces, keeping your home clean and fresh. This innovative device is equipped with various smart sensors that monitor your pet's toilet activity and activate to automatically clean after use. The device connects to the sewer system and ensures efficient waste removal without the need for intervention from the owner. Additionally, the toilet has a large flushable storage capacity, making it ideal for multi-cat households. The Petgugu cat litter bowl is designed for use with water-soluble litters and offers a range of additional ... >>
The attractiveness of caring men
14.04.2024
The stereotype that women prefer "bad boys" has long been widespread. However, recent research conducted by British scientists from Monash University offers a new perspective on this issue. They looked at how women responded to men's emotional responsibility and willingness to help others. The study's findings could change our understanding of what makes men attractive to women. A study conducted by scientists from Monash University leads to new findings about men's attractiveness to women. In the experiment, women were shown photographs of men with brief stories about their behavior in various situations, including their reaction to an encounter with a homeless person. Some of the men ignored the homeless man, while others helped him, such as buying him food. A study found that men who showed empathy and kindness were more attractive to women compared to men who showed empathy and kindness. ... >>
| Random news from the Archive hypoallergenic poplar
24.12.2022
The researchers have edited the genes of the trees so that in the spring they produce only "hairless" seeds that do not cause allergies.
Selective breeding of plants is very broad and is aimed at giving them new useful traits or enhancing certain qualities. For example, scientists change the size, appearance, nutritional value, yield, resistance to pests, heat, cold, salinity or drought.
As a rule, such work is carried out by selecting and crossing individual plants that have the necessary properties. However, the work is laborious and usually requires a certain amount of waiting time for the plants to mature.
If the reproductive cycle of vegetable plants is only a few months, then for trees this period can include several years - this is a very long cycle, which significantly slows down the work of scientists. But it seems that in a new study, scientists from the University of Georgia solved two main problems at once - firstly, they reduced the reproductive cycle of poplars, and secondly, they made their seeds “naked”, and therefore hypoallergenic.
In the course of the study, the scientists turned to the CRISPR gene-editing system to try to speed up the process. For their experiment, the scientists chose poplar, which has a long juvenile period - from 7 to 10 years.
Previously, in such studies, scientists usually focused on gene regulators that directly affect the development of the plant. But, unfortunately, success in poplar research seemed patchy. In the new study, scientists completely changed the approach and eliminated the negative impact.
Using the CRISPR gene editing system, the scientists eliminated the CENTRORADIALIS (CEN) gene, which suppresses flowering initiation in young plants. According to study co-author CJ Tsai, he and his colleagues managed to reduce the flowering time of poplar from at least 7 years to 3-4 months, and the annual period of organ development to several days.
Scientists believe that this breakthrough will further allow scientists to accelerate the process of deducing new beneficial traits in plants. By the way, researchers have already taken advantage of this “accelerator” of the process - in the course of the study, they were able to edit another poplar gene to reduce the number of cotton-like seed attachments that cause allergies in thousands of people. Tsai says the study has been successful, and scientists have now provided the molecular basis for growing "bald" seeds, which can further reduce the amount of allergens carried.
|
Other interesting news:
▪ Reproduced the scent of an Egyptian mummy
▪ gold mining bacteria
▪ RFID tag 4x4 mm with built-in antenna
▪ Seals get the flu too
▪ plastic from tomato skins
News feed of science and technology, new electronics
Interesting materials of the Free Technical Library:
▪ section of the site Home workshop. Article selection
▪ article Shooting a cartoon. video art
▪ article Why does corn have a silk strand? Detailed answer
▪ Tladiant's article is dubious. Legends, cultivation, methods of application
▪ article Relay-regulator with thermal compensation. Encyclopedia of radio electronics and electrical engineering
▪ article Moving coins at the speed of light. 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