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Cowin's GNSS antennas comprise all common global satellite services such as GPS, GLONASS, GALILEO and BeiDou. Our GNSS antennas are suited for use in the area of public security, in the transport and logistics sector as well as for protection against theft and in industrial applications. Cowin has various types of GNSS antennas for sale at proper price, which not only include active and passive internal antennas, but also magnetic base, round adhesive and screw mount external antennas.

Types of GNSS Antenna

  • GPS/GLONASS External Antenna +
    Magnetic base GPS external antenna with RG174 cable and SMA Male connector, external GPS antenna cable length can customized, external GPS antenna connector is usual SMA and fakra, sure it is ok to cu...
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  • GPS/GLONASS Internal Antenna +
    25*25MM active internal ceramic GPS patch antenna with RF1.13 cable IPEX connector, the internal GPS antenna can do active and passive, the ceramic GPS antenna size has usual 25*25*4,25*25*2, 15*15*4,15*15*2,12*1...
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FAQs of GNSS Antenna

  • Q What are the parameters of GPS antenna? A

    GPS antenna has four important parameters: Gain, VSWR, Noise figure and Axial ratio. The axial ratio is especially emphasized, which is an important index to measure the signal gain difference of the whole machine in different directions. Since satellites are randomly distributed across the hemispheres of the sky, it is important to ensure that antennas are sensitive in all directions. The axial ratio is affected by antenna performance, external structure, internal circuit and EMI.

  • Q How to install GPS antenna? A

    A. Don't get too close to the metal objects, 20cm metal object more than 2m.

    B. Where the feeder bends, the bending radius should be more than 20 times the diameter of the feeder.

    C. The GPS antenna extension cable length is usually 3M, and use Shielding wire, the extra cable should not be cut short and connected manually, otherwise which will seriously affect the satellite signal transmission. The extra cable should be coiled on one end of the antenna rather than close to the host bus.

    D. The GPS antenna should not be installed near other transmitting and receiving devices, Prevent other transmitting antennas radiation direction in the direction of the ceramic antenna.

Why does GPS go offline usually ?

A. Car GPS locator is power off or blackout, call the SIM card number installed on the device by mobile. If prompted to shut down, the GPS has no power on and needs to check the GPS connection wire.

B. The network communication is not normal, GPS locator device has no GPS signal; if the phone call is normal, the car locator is still offline, this is the reason, do not install the location with too closed, do not have metal cover, as close as possible to the above installation.

C. Hardware and software issues, which require the design engineer to check circuit diagram and electronic parts quality.

D. Antenna issue, the antenna selection should consider device impedance, active antenna or passive antenna, primary amplification or secondary amplification, antenna power, etc.

What factors is it that affect the performance of GPS antenna?

A. Ceramic patch: the ceramic powder quality and sintering process directly affect the performance of the GNSS antenna. Currently, the main ceramic patches are 25*25, 18*18, 15*15 and 12*12 in the market, The larger the ceramic area, the greater the dielectric constant, the higher the resonance frequency and the better the receiving effect, The ceramic patches are mostly square in design, to ensure that the resonance in the XY direction is basically consistent, so as to achieve the effect of uniform reception of satellite signal.

B. Silver layer: The silver layer on the surface of the ceramic antenna can affect the resonant frequency, the ideal frequency point of GPS ceramic patch is 1575.42mhz, but the antenna frequency point is very easily influenced by the surrounding environment, especially when it is assembled in the equipment, the frequency point must be adjusted back to 1575.42mhz by adjusting the shape of the silver surface coating. Therefore, GPS manufacturers must cooperate with antenna manufacturers when purchasing antennas to provide complete device samples for testing.

C. Feed point: The ceramic antenna collects resonance signals through the feed point and sends them to the back end. Because of antenna impedance matching, the feed point is generally not in the center of the antenna, but in the XY direction to make small adjustments. This impedance matching method is simple and does not increase the cost. Moving only along a single axis is called a single offset antenna, and moving on both axes is called a double offset antenna.

D. Amplifying circuit: Bear ceramic antenna PCB shape and area, Due to the characteristics of GPS touchdown rebound, when the background is 7cm×7cm and increases continuously, patch antenna's performance can be maximized.Although restricted by external structure and other factors, but as far as possible to maintain a similar area and uniform shape. The amplifier gain must be selected in conjunction with the LNA gain at the back end. The GSC3F of Sirf requires that the total gain before signal input shall not exceed 29dB, otherwise, signal supersaturation will generate self-excitation.

Applications of GNSS Antenna

GNSS systems where revolutionary in the area of Navigation by providing positioning and navigation capabilities to the autonomous vehicles. With precise positioning, GNSS can be used for lane or track determination for road and rail vehicles 

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