Nowadays, GPS antennas are used in transport fleets, scientific and technological exploration, military tracking and other industries, because they can not only track the location of the place, but also predict some objects on the route; according to the design, they can be divided into flat antennas and spiral antennas, among which spiral antennas have stronger satellite search capabilities. When using a GPS antenna, you also need to know its phase center, so what is the phase center? The following editor will tell you:

GPS antenna

The phase center of a GPS antenna should be a theoretical point, or it can be said that in theory, the signal radiated by the antenna is radiated outward with this point as the center of the circle, and this point is the so-called phase center; but this point basically does not exist in the actual GPS antenna, because the manufactured GPS antenna cannot be so perfect, so the phase center of the actual antenna is an area.

The phase center of the GPS antenna receiver, which is usually called the electrical center of the GPS antenna receiver, is the reference point of a measuring instrument. Studying the change law of the phase center of the GPS antenna receiver is an important link to improve the measurement accuracy.

For the convenience of use, the GPS antenna receiver is usually separated from the host, and they are connected by a coaxial cable of a certain length. When the signal enters the antenna, it is amplified, transmitted by cable, amplified again, and then demodulated, so there is a delay, which is the internal delay.

In the process of GPS antenna measurement, we usually put the antenna of the GPS antenna receiver on the mark point, and usually take the center of the upper surface of the antenna as the phase center of the GPS antenna receiver, but in fact it is not the case. We know that when the GPS antenna receiver is working, it needs to receive more than four GPS antenna satellite signals at the same time for amplification, transmission, correlation demodulation, and calculation to find out parameters such as time, position, speed, and direction. The correlation demodulation point refers to the reference point of the delay from the satellite signal to the GPS receiver. For each satellite signal, the correlation demodulation point is the reference point (or starting point) of the measurement.

The above is the definition of the phase center of the GPS antenna. Because the GPS antenna is the most important receiving component in the GPS device, its performance will be directly related to the product quality of the GPS device, so we need to carefully judge its quality when purchasing.