The Development Based On Beidou Transceiver Front-end

Beidou with full name of the Beidou satellite navigation system following Global Positioning System (GPS) of the United States, GLONASS of Russian, in order to achieve the grant, quick navigation positioning, two-way short message communication and other functions for the target for China’s own scientific and technological development and needs designed and developed hasregional active3D satellite positioning and communications systems, referred to as the CNSS. Especially when our country pay more and more attention since the navigation in the national life and military as well as the Beidou "Double Star" positioning program is established, China has been increasing the Beidou cause of concern and research, the Beidou second-generation navigation system is also matureup. At present, the positioning accuracy of the Beidou system in our region and the United States GPS considerable, and can realize two-way short message communication which is not provided by the United States’GPS, Compass with its superior performance to play in the national economy, rescue and military fieldsa huge role, with strategic importance. A system to achieve information transmission, receiving and transmitting system is indispensable, good or bad performance of the receiver and transmitter will directly determine the use of the entire system functions, this paper studies the Beidou ground terminal of the receive and transmit highperformance front-end is of great significance and broad prospects.The receiver module of Beidou RF components in the S-band (operating frequency band is2491.75±4.08MHz). the transmitter module of Beidou RF components in the L-band (operating band1615.68±4.08MHz) Firstly, the RF receiver and its front-end a detailed theoreticaland select the Avago ATF-34143low-noise amplifier tubes and Hittite’s HMC monolithic amplifier chip simulation to design a working receiver in the Beidou-band low-noise amplifier before the class of the receiver module is responsible for receiving the stationsignal and the pre-filter, low noise amplification and so on. Second, for the RF transceiver channel describes the principle and structure of the PLL frequency source analysis, and introduced the structure and principles of dual-band radio frequency integrated phase-locked loop chip Si-4133produced by Silicon Laboratories Inc and broadband quadraturethe demodulator AD8347produced by Analog Devices and the demodulation of the RF can gain amplifier VGA, baseband variable gain amplifier and receiver demodulation principle, for the output of demodulator mixer and baseband amplifier inputthe design of a fifth-order bandpass filter baseband signal is filtered and combined with research to give a specific receive channel design ideas, and finally combined with the ADS electromagnetic simulation software simulation of the receiving system. Then introduced the digital modulation, the channel signal of the subject designed by the BPSK modulator modulation to launch the carrier frequency, the band-pass filter to filter sidelobe power spectrum, image spectrum and other combinations of the spectrum, and then zoom into the front RF power amplifier circuita certain power. Finally, the article also made on the feasibility of verification, use Protel to draw the circuit layout and circuit board debugging, with a spectrum analyzer and test software on the the Beidou RF transceiver module performance, a series of tests, and given a diagram of the final instrument test data to prove this thesis are feasible, the performance of the transceiver components meet the design requirements. The end result:the IF frequency is12.24MHz, IF power is-2±1.5dBm, output demodulated signal power≥40dBm, of-band spurious suppression≥-70dBW/4KHz, local oscillator phase noise to achieve less than1KHz equal-75dBc/Hz, modulation characteristics of carrier suppression≥30dB,10KHz less than or equal to-85dBc/Hz, modulation phase error<3°, the output clock frequency of48.96MHz which output clock power greater than7dBm.