source:truck tracking webfleet solutions release time:2022-09-27 Hits: Popular:realtime gps tracker online
A four-armed helical antenna consists of four specially curved metal lines. No grounding is required. It has the characteristics of a Zapper antenna, and also has the characteristics of a vertical antenna. This ingenious structure makes the antenna gain 3dB in any direction, increasing the time for satellite signal reception. The four-armed helical antenna has a full 360-degree receiving capability, so when combined with the pda, the four-armed helical antenna can receive regardless of the placement position of the PDA. Good reception limits. Using this kind of antenna, when the satellite appears 10 degrees above the ground level, the signal transmitted by the satellite can be received.
However, if there are many interference sources near the ground receiving station, the four-armed helical antenna is not suitable, because the four-armed helical antenna has a gain in the horizontal direction, which will amplify the noise and interfere with the reception of satellite signals. However, technology is advancing, and the four-arm helical antenna produced today can break through many of the limitations of traditional antennas. The antenna is made of ceramic, and the Near-Field is extremely small, only about 3~5mm, while the Near-Field of some traditional antennas is even as high as 1m. The smaller the Near-Field, the less human body will cause interference when the user holds the GPS device. The current quadrifilar helical antenna also features a complete balun circuit (Balun) design, which isolates the noise around the antenna, thus allowing antennas of various functions to coexist in a very small space without interfering with each other . The importance of this feature is indescribable for handheld electronic products with increasingly diverse integration functions and emphasis on light, thin, and short.