The VCO Design For Beidou Satellite Navigation Transceiver

In recent years, the global navigation industry has become now one of internationally recognized eight big wireless industries. Beidou is the satellite navigation positioning system which is researched and developed by our own country, it plays an extremely important role in our country's economy and national defense. The RF front end is one important component of Beidou transceiver. Due to the CMOS process successful application on analog and RF circuit, more and more RF cells can realize the monolithic integration, in these chips the performance of low noise amplifier and local oscillator is especially important. The main research of this paper is to introduce the LC voltage controlled oscillators which are used in Beidou navigation system up-direction L and down-direction S frequency band.The theory of the LC-VCO and phase noise is introduced in this paper, the low phase noise LC-VCO's design and realization are emphasized. The technologies which are proposed by the literatures to reduce the phase noise are carried out simulation and analysis, which has proven that these proposed technologies can be used in this paper.The LC-VCOs which are worked separately in the Beidou satellite navigational system's transmitter and receiver were designed based on SMIC 0.18um RF CMOS process in this paper. The plane spiral inductance, MOS variable capacitance and RF capacitance were detailed analysized, because the components which are mentioned above provided by SMIC process are limited, based on this situation and the reducing phase noise technologies which are proposed by the literatures, the two VCOs were designed and layouted, the layout post-simulation was carried out, and the work reachs the level of manufacturing. The layout post simulations had shown that: (1) when the controlled voltage is from 0V to 1.8V, the frequency of VCO which is worked in Beidou satellite's L frequency band changes from 1550 to 1660MHz, the phase noise is -70.86dBc/Hz at 10KHz; -101.5dBc/Hz at 100KHz and -127.8dBc/Hz at 1MHz. (2) when the controlled voltage is from 0V to 1.8 V, the frequency of VCO which is worked on Beidou satellite's S frequency band changs from 2375 to 2710MHz, the phase noise is -53.1dBc/Hz at 10KHz; -80.17dBc/Hz at 100KHz and-103.4dBc/Hz at 1MHz.