Car navigation ceramic antenna

　　Car navigation ceramic antenna is a key component for receiving satellite signals in car navigation systems. The following will introduce its characteristics, working principle, type, performance parameters and other dimensions in detail:

　　Features

　　High sensitivity: It can receive weak satellite signals. Even when the satellite signal is weak, such as in a city canyon with tall buildings or near an underground parking lot, it can capture the signal as much as possible to ensure the normal operation of the navigation system and achieve accurate positioning.

　　Low noise: It can reduce interference during signal transmission, reduce the impact of noise on the signal, make the received satellite signal purer, and thus improve the accuracy and stability of positioning.

　　Miniaturization: It is small in size and easy to install in various locations inside the car, such as under the front windshield, under the roof interior panel, etc. It will not take up too much space and is also conducive to the overall design and layout of the car.

　　Strong anti-interference ability: The ceramic material itself has a certain anti-electromagnetic interference performance, and can work stably in the complex electromagnetic environment inside the car, reducing the impact of interference signals from the car engine, on-board electronic equipment, etc. on satellite signal reception.

　　Good durability: It has good weather resistance and corrosion resistance, and can withstand the high temperature, low temperature, humidity, dust and other conditions faced by cars when driving in various harsh environments, ensuring the stability of the antenna's performance and service life.

　　Working principle

　　Dielectric resonance: The dielectric properties of ceramic materials are used to form a dielectric resonator. When the satellite signal reaches the ceramic antenna, the ceramic material resonates with the signal, so that the signal is enhanced and amplified in the ceramic body.

　　Signal amplification: The built-in low-noise amplifier (LNA) amplifies the weak satellite signal after resonance, improves the strength and quality of the signal, so that the subsequent signal processing circuit can better process and analyze the signal.

　　Signal processing: The amplified signal is transmitted to the signal processing unit of the car navigation system, where the received signal is processed to extract positioning information, such as the longitude, latitude, altitude, etc. of the vehicle, so as to achieve accurate positioning of the car.

　　Type

　　Passive ceramic antenna: It does not contain a built-in amplifier and relies only on the resonance characteristics of the ceramic medium to receive and enhance satellite signals. It has a simple structure and low cost, but the signal reception capability is relatively weak. It is generally suitable for scenes with low signal strength requirements or good surrounding signal environment.

　　Active ceramic antenna: built-in low-noise amplifier, can effectively amplify weak satellite signals, improve the antenna's receiving sensitivity and signal quality. Active ceramic antennas usually have higher gain and can work better in weak signal environments, but require external power supply.

　　Performance parameters

　　Gain: an indicator that measures the antenna's ability to amplify the received satellite signal, usually in decibels (dB). The higher the gain, the stronger the antenna's ability to amplify the signal, and the better the signal reception effect. Generally, the gain of a car navigation ceramic antenna is around 20dB to 30dB.

　　Standing wave ratio: reflects the impedance matching between the antenna and the transmission line. The lower the standing wave ratio, the better the match between the antenna and the transmission line, the smaller the signal reflection, and the higher the transmission efficiency. Generally, the standing wave ratio is required to be less than 2.

　　Noise factor: indicates the noise level introduced by the antenna during the signal reception process. The lower the noise factor, the less interference the antenna has on the signal and the higher the signal quality.

　　Axis ratio: an indicator that measures the difference in signal gain of the antenna in different directions. Since the position of satellites in the sky is random, the antenna is required to have similar sensitivity in all directions. The closer the axial ratio is to 1, the better the antenna's directivity is, and the more balanced the ability to receive signals from different directions is.

　　Installation location

　　Roof: The roof is one of the best locations for signal reception, because it is unobstructed and can directly receive satellite signals, reducing signal reflection and attenuation. Ceramic antennas can usually be installed in the front or middle of the roof and fixed with a special bracket or glue.

　　Under the front windshield: Install the antenna on the dashboard under the front windshield. This installation method is relatively concealed and does not affect the appearance of the vehicle. At the same time, it can also receive satellite signals of a certain strength, but it may be affected by the film or metal decorative strips on the windshield.

　　In the A-pillar interior panel: Some models will install the antenna in the A-pillar interior panel, which is relatively concealed and close to the roof, and the signal reception effect is also good, but care should be taken to avoid damaging the interior panel and antenna during installation.