| Summary: | 碩士 === 國立臺灣科技大學 === 電子工程系 === 95 === This dissertation aims to explore the influence of the LNA noise on the GPS signal reception. In addition, it also tries to solve the problem of the poor GPS signal reception caused by the noise of the GPS chip IN band resulting from the USB itself. When designing the LNA, we should give priority to think about the volume of the noise in matching the circuits, rather than the purpose of amplifying. There is a significant influence of the layout and the circuit matching on the GPS signal reception. It is also suggested to conduct the actual measuring for both matching methods in the circuit matching to ensure the optimization of the matching values.
While using other active components on the GPS products, it is necessary to measure the EMI value of the active components by anticipation, especially on PND products, since they have possessed a lot of functions such as CPU, LCD and AUDIO. Therefore, the precaution of the EMI plays a decisive role here. In CPU wiring, it is recommended to measure the signal of every clock in advance to see if it will generate the harmonic and if it lies in between the GPS IN BAND. Meanwhile, as the effect of the antenna to the clock signal and other periodical pulses, the long trace should be as short as possible and kept far away from the GPS segment.
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