GPS is a terminal for positioning or navigation by receiving satellite signals. An antenna must be used to receive the signal. GPS satellite signal is divided into L1 and L2, the frequency is 1575.42MHZ and 1228MHZ respectively, among them L1 is the open civil signal, the signal is circular polarization. The signal strength is about -166dBW, which is a relatively weak signal. These characteristics determine the need to prepare a special antenna for GPS signal reception.