A ceramic piece:The quality of ceramic powders and sintering processes directly affect its performance. Ceramic pieces are mainly 25 × 25,18 × 18,15 × 15,
12 × 12. Ceramic sheet size, the greater the dielectric constant, the higher the resonance frequency, the better the acceptance. Most ceramic square design, to
In the XY direction to ensure consistent resonance, so as to achieve a uniform closing star effect.
2, the silver layer:Silver layer ceramic antenna surface can affect the antenna resonance frequency. Ideal for accurate frequency GPS ceramic pieces fall 1575.42MHz, but the antenna frequency
Highly vulnerable to the impact the surrounding environment, particularly in the assembly of the machine, you must adjust the shape of the silver surface coating to keep re-adjusting the frequency 1575.42MHz.
3, the feed point:Ceramic antenna resonance signals collected by the feed point and send it to the backend. Because of the antenna impedance matching, antenna feed point is generally not in the
The center, but to do minor adjustments in the XY direction. Such simple impedance matching without increasing the cost. Moving only one known in the uniaxial direction bias
Antenna moves in two axes are called to do double bias.
4, the amplifier circuit:Carrying a ceramic PCB antenna shape and size. Since the GPS has a touchdown rebound characteristics, when the background is 7cm × 7cm without interruption earth,
performance patch antenna can play to the extreme. Although the exterior of the structure and other factors, but try to maintain a considerable area and uniform shape. Amplifier gain
The choice must match the back-end LNA gain. Sirf before the GSC3F request signal input shall not exceed the total gain 29dB, otherwise the signal will produce oversaturated self-excited.
GPS antenna has four important parameters: Gain (Gain), VSWR (VSWR), noise figure (Noise figure), axial ratio (Axial ratio).
With particular emphasis on the axial ratio, which is an important indicator of overall signal gain for different directions of difference. Since the satellites are randomly distributed in the sky hemisphere,
Therefore, the sensitivity of the antenna in all directions to ensure both are very similar importance. Receive antenna axial ratio performance, appearance of the structure, the whole internal circuits and EMI and other effects.
With particular emphasis on the axial ratio, which is an important indicator of overall signal gain for different directions of difference. Since the satellites are randomly distributed in the sky hemisphere,
Therefore, the sensitivity of the antenna in all directions to ensure both are very similar importance. Receive antenna axial ratio performance, appearance of the structure, the whole internal circuits and EMI and other effects.