GPS is a terminal that receives satellite signals for positioning or navigation. And to receive that signal, you need an antenna. GPS satellite signals are divided into L1 and L2, with frequencies of 1575.42MHZ and 1228MHZ, respectively, of which L1 is an open civilian signal, and the signal is circular polarization. The signal strength is about 166-DBM, which is a relatively weak signal. These characteristics determine that special antennas should be prepared for the reception of GPS signals.

First, the basic principle of GPS antenna

The basic principle of GPS antenna is to use electromagnetic wave propagation and reception to achieve positioning and navigation functions.
The antenna receives signals from the satellite and converts them into electrical signals.
These signals are then processed by the receiver to calculate the distance between the receiver and the satellite, thereby determining the receiver's position.

Second, the working mode of GPS antenna

1. Receive satellite signals
GPS antennas receive navigation information by receiving radio signals from satellites.
These signals are sent by the satellite at a fixed frequency and code, and are received by the receiving element of the antenna.
2. Signal amplification and filtering
After receiving the signal, the antenna passes the signal to the amplifier, which increases the strength of the signal.
The signal then passes through a filter to remove noise and interference, making the signal clearer and more reliable.
3. Signal conversion
After amplification and filtering, the signal needs to be converted into a digital signal for the receiver to process and calculate.
This process is called analog-to-digital conversion, and by converting analog signals to digital signals, the distance between the receiver and the satellite can be calculated more accurately.
4. Data processing
After the analog-to-digital conversion, the digital signal is transmitted to the receiver for processing.
The receiver uses the received signal to calculate the distance between the receiver and the satellite, and triangulates through the signals of multiple satellites to determine the position of the receiver.

Third, the characteristics and applications of GPS antenna

1. Multi-band support
With the continuous development of GPS technology, modern GPS antennas can support signal reception in multiple frequency bands.
These frequency bands include L1, L2, L5, etc., and each frequency band has different characteristics and uses.
Multi-band support can improve the accuracy and reliability of positioning.
2. Antenna gain
The gain of a GPS antenna is the ability of the antenna to receive signals.
The higher the gain, the stronger the signal received by the antenna, and the higher the positioning accuracy.
Therefore, antenna gain is an important index to measure antenna performance.
3. Antenna form
There are many forms of GPS antenna, including internal antenna, external antenna, ceramic antenna and so on.
Different types of antennas are suitable for different application scenarios, and users can choose the appropriate antenna according to their needs.
4. Application field
GPS antennas are widely used in aerospace, military, transportation, mapping, navigation and other fields.

In aerospace, antennas receive satellite signals to guide aircraft; In the military field, antennas are used for military positioning and navigation; In the field of transportation, antennas are used for vehicle positioning and navigation.

In short, GPS antenna is an important part of navigation satellite system, which realizes positioning and navigation functions by receiving satellite signals.