25*25mm GLONASS GPS Navigation Tracker Antenna Introduction: ⒈ GPS antennas are divided into vertical polarization and circular polarization in terms of polarization. Vertical polarization is not as effective as circular polarization. Therefore, except for special cases, GPS antennas will use circular polarization and linear polarization. ⒉ GPS antennas are divided into built-in antennas and external antennas in terms of placement. The mounting position of the antenna is also very important. Early GPS handsets mostly used eversion antennas. At this time, the antennas were basically isolated from the interior of the whole machine, and EMI hardly affected them, and the star collection effect was very good. With the trend of miniaturization, GPS antennas are mostly built-in. At this time, the antenna must be above all metal devices, and the shell must be plated and grounded well, away from EMI interference sources, such as CPU, SDRAM, SD card, crystal…