Introduction to GPS antenna selection
Time：2021-09-28 15:44:47 Author：Suzhou Cowin Antenna Electronics Click：
As the most important receiving part of GPS, GPS antenna is equivalent to human ears and eyes. It is the main window of GPS. The quality of GPS antenna is particularly critical to the product performance of the whole machine,
1. GPS passive antenna
When using passive GPS antenna, because only one ceramic chip receives the satellite signal from the sky and is directly connected to the module, this connection mode has simple structure, low cost, mature technology and small duty volume. It is suitable for emphasizing compact space GPS navigation products, Bluetooth GPS, mobile phone GPS and other small GPS consumer products.
The layout of this GPS passive antenna is from the antenna pin to the rf-in pin of the module. This wire needs impedance matching, and there can be no electromagnetic interference near the antenna, which has high requirements for PCB design and whole machine design. However, if the well-designed passive antenna GPS products also have very good performance effect and save power consumption.
2. GPS active antenna
Generally, for the equipment or vehicle mounted machine, because there is often a distance between the equipment and the GPS receiving module, considering the convenience of installation, there may be a distance of more than 1m. In this case, we can only choose the active GPS antenna. The active antenna needs to be compensated due to the signal attenuation of the antenna length. Generally speaking, there are two-stage low-noise amplifiers to amplify the signal at the front end of the antenna, and the amplified signal is output through the cable, The cable synchronously provides the DC voltage required by LNA, and since the signal received by the antenna completes signal reception and antenna amplification in the active antenna receiving head, and is far away from GPS equipment or other electrical equipment, the interference source is the smallest.
Moreover, due to the extended antenna distance, the installation position can choose a very ideal environment. Therefore, in actual use, it is often felt that the signal is strong, especially when the weak signal is started. Because the internal secondary amplification will also have a certain gain, the start-up time is often faster. However, due to the internal secondary LNA, it will also consume a certain amount of electric energy, and the product performance of different manufacturers is also different. The performance of active antenna is mainly affected by ceramic antenna chip and LNA, as well as antenna design, impedance matching, screen spectrum test, antenna fine tuning and output wire terminal.
3. Gamin navigation GPS antenna
Another special type of active antenna, marine antenna, in addition to the performance requirements of ordinary antenna, also needs to have acid-base and salt fog resistance, good sealing performance, wind and wave impact resistance. Due to the excellent signal of marine GPS itself, the sensitivity requirements are not high, and higher reliability is more important. Due to the large volume of navigation antenna and the large reflection area of PCB, the overall gain is high and the stability is good.
1. GPS passive antenna
When using passive GPS antenna, because only one ceramic chip receives the satellite signal from the sky and is directly connected to the module, this connection mode has simple structure, low cost, mature technology and small duty volume. It is suitable for emphasizing compact space GPS navigation products, Bluetooth GPS, mobile phone GPS and other small GPS consumer products.
The layout of this GPS passive antenna is from the antenna pin to the rf-in pin of the module. This wire needs impedance matching, and there can be no electromagnetic interference near the antenna, which has high requirements for PCB design and whole machine design. However, if the well-designed passive antenna GPS products also have very good performance effect and save power consumption.
2. GPS active antenna
Generally, for the equipment or vehicle mounted machine, because there is often a distance between the equipment and the GPS receiving module, considering the convenience of installation, there may be a distance of more than 1m. In this case, we can only choose the active GPS antenna. The active antenna needs to be compensated due to the signal attenuation of the antenna length. Generally speaking, there are two-stage low-noise amplifiers to amplify the signal at the front end of the antenna, and the amplified signal is output through the cable, The cable synchronously provides the DC voltage required by LNA, and since the signal received by the antenna completes signal reception and antenna amplification in the active antenna receiving head, and is far away from GPS equipment or other electrical equipment, the interference source is the smallest.
Moreover, due to the extended antenna distance, the installation position can choose a very ideal environment. Therefore, in actual use, it is often felt that the signal is strong, especially when the weak signal is started. Because the internal secondary amplification will also have a certain gain, the start-up time is often faster. However, due to the internal secondary LNA, it will also consume a certain amount of electric energy, and the product performance of different manufacturers is also different. The performance of active antenna is mainly affected by ceramic antenna chip and LNA, as well as antenna design, impedance matching, screen spectrum test, antenna fine tuning and output wire terminal.
3. Gamin navigation GPS antenna
Another special type of active antenna, marine antenna, in addition to the performance requirements of ordinary antenna, also needs to have acid-base and salt fog resistance, good sealing performance, wind and wave impact resistance. Due to the excellent signal of marine GPS itself, the sensitivity requirements are not high, and higher reliability is more important. Due to the large volume of navigation antenna and the large reflection area of PCB, the overall gain is high and the stability is good.