470-862MHz Yagi Antenna
Yagi Antenna Definition
It is an end-fire antenna composed of an active vibrator, a passive reflector and several passive directors arranged in parallel. In the 1920s, this kind of antenna was invented by Yagi Shuji and Uda Tailang of Tohoku University in Japan, which is called “Yagi Uda Antenna”, or “Yagi Antenna” for short.
UHF and VHF
1. UHF, Ultra High Frequency (Ultra High Frequency) refers to radio waves with a wavelength range of 1m~1dm and a frequency of 300~3000MHz, which are often used in the field of mobile communication and radio and television.
UHF is mainly used for short-distance communication, which can be sent and received with small and short antennas, which is suitable for mobile communication.
The uses are as follows:
①. Analog TV and digital TV broadcasting: (470MHz～770MHz); HD digital antenna frequency range: 470-862MHz
②. Military aviation wireless mobile phone: (800MHz, 1.5GHz);
③. Mobile phone (450MHz North America GSM/850MHz North America GSM/900MHzGSM/1800MHz(GSM/PCS)/1900MHz North America GSM/Japan and Taiwan PHS, 1.5GHz)
④. Wireless network: (2.4GHz);
⑤. Amateur radio: (430MHz, 1200MHz, 2400MHz).
⑥. Low power radio: (409MHz (en:Personal radio service, PRS)/ 446MHz (en: PMR446), 462MHz (en: Family Radio Service, FRS /en: General Mobile Radio Service, GMRS)/467MHz (FRS) )
2. VHF, Very high frequency, refers to the radio waves in the frequency band from 30Mhz to 300MHz. Lower frequencies than VHF radios are High Frequency (HF), and higher frequencies than VHF Radios are Ultra High Frequency (UHF)
VHF is mostly used for radio and television broadcasts, and is also a communication channel for aviation and navigation.
VHF is mainly used for shorter distance transmission. Unlike high frequency (HF), the ionosphere usually does not reflect the VHF signal, and VHF is often affected by environmental factors such as terrain.
Advantages of Yagi Antenna
Yagi antennas work really well. It has good directivity and higher gain than dipole antennas. It is particularly effective for direction finding and long-distance communication. If coupled with the elevation and azimuth rotation control devices, it is possible to communicate with radio stations in all directions, including space vehicles, at will, and this feeling cannot be obtained from an upright antenna.