Comparison between active GPS antenna and passive GPS antenna

　　Comparison between active GPS antenna and passive GPS antenna

　　In application scenarios such as equipment or vehicle-mounted machines, there is often a certain distance between the equipment and the GPS receiving module, and for the convenience of installation, the distance may exceed 1 meter. In this case, the difference between active GPS antenna and passive GPS antenna is particularly obvious, and the specific comparison is as follows:

　　1. Signal attenuation and compensation capability

　　Active GPS antenna: Due to the long distance between the antenna and the receiving module (more than 1 meter), the signal will be attenuated during transmission, and the active GPS antenna can deal with this problem well. Its front end usually uses a two-stage low-noise amplifier (LNA) to amplify the received signal, which can effectively compensate for the signal attenuation caused by the distance and ensure that the signal strength transmitted to the receiving module meets the requirements. At the same time, the cable connecting the antenna and the device will synchronously provide the required DC voltage for the LNA, without the need for additional power supply lines, simplifying the installation process.

　　Passive GPS antenna: There is no signal amplification function. When the distance from the receiving module exceeds 1 meter, the signal attenuation is serious, and it cannot be guaranteed that the receiving module can stably receive a signal of sufficient strength. Therefore, it is not applicable in such a long-distance scenario.

　　II. Anti-interference performance

　　Active GPS antenna: Its signal reception and amplification process is completed at the antenna receiving end, and the antenna installation position is usually far away from the GPS device or other electronic equipment, and is minimally affected by interference sources. This makes the signal transmission process more stable and reduces the problem of signal loss or inaccurate positioning caused by interference.

　　Passive GPS antenna: The signal is transmitted directly from the antenna to the receiving module. If the installation position is close to other electronic devices, it is susceptible to electromagnetic interference, especially in long-distance transmission. The impact of interference on the signal will be more obvious, thereby affecting the positioning effect.

　　III. Installation flexibility and signal reception effect

　　Active GPS antenna: Since the distance can be extended, the choice of installation location is more flexible, and an environment with more ideal signal reception conditions can be selected (such as a place with a wide field of view and less obstruction). In actual use, due to the better installation environment and amplified signals, users usually feel that the signal is stronger, and the positioning is more stable and accurate.

　　Passive GPS antenna: Limited by the signal transmission distance and the characteristics of no amplification function, the installation position needs to be as close to the receiving module as possible, making it difficult to select the most ideal signal receiving environment, and the signal reception effect will be greatly reduced in complex environments.

　　In summary, in equipment or vehicle-mounted machines, when the distance between the GPS antenna and the receiving module exceeds 1 meter, the active GPS antenna becomes the only suitable choice due to its signal attenuation compensation ability, strong anti-interference and flexible installation advantages; while the passive GPS antenna is more suitable for scenarios where the distance between the antenna and the receiving module is very close (usually within 1 meter) and the signal environment is good.