There are generally two types of GPS antennas currently on the market - planar antennas and quadrifilar helical antennas.
Tablet GPS Antenna
Plan view GPS antennas have become a widely used antenna type because of their durability and ease of manufacture. It can be circular, square or oblate in shape, like a painted copper printed circuit board. It is composed of one or several pieces of copper, so the more common appearance of the GPS antenna is a small lump, like a big cake. Since the antenna can be made small, it is suitable for airlines and personal hand-held applications.
Another main feature of the antenna is the gain value method, that is, specificity. Use the specific performance of the antenna to improve its anti-interference and anti-multipath effect. In precise positioning, the stability of the GPS antenna is a crucial indicator. However, in more common navigation applications, we want to use an omni-directional antenna to receive the signal that is at least visible to the entire sky within five degrees above the antenna at dawn.
Quadrifilar helical antenna
The quadrifilar helical GPS antenna consists of four specially curved wires. No grounding device is required. This proper configuration enables the antenna to have a gain of 3dB in all directions, enhancing the duration of signal reception. The four-arm helical antenna has more than 360-degree receiving capability, so when it is integrated with the pda, no matter where the PDA is placed, the four-arm helical antenna can receive it, which is different from the limitation that the GPS antenna of the tablet computer must be placed for better reception. With such an antenna, when the communication satellite happens to be 10°C above the ground, the communication satellite signal can be received.
If there are many interference signals around the receiving station on the road, the four-armed helical GPS antenna is not suitable, because the four-armed helical antenna has a level gain value, which will increase the noise and affect the signal reception. But with the development of technology, the quadrifilar helix antenna manufactured today can improve the limitations of many traditional antennas. The antenna is made of porcelain, and its line is not big, only about 3~5mm, while the line of some traditional antennas can even reach 1 meter. The smaller the line, the less interference caused by the user's body when holding the GPS device . Another feature of the current quadrifilar helical antenna is the complete balun circuit principle, which can protect the noise around the antenna, thereby allowing antennas with various functions to coexist in a particularly small space without affecting each other. As the functions of integration become more and more diversified, and more and more attention is paid to thin and light hand-held electronic devices, the importance of this feature cannot be expressed in words.