Design And Implememtation Of The L Band RF Front-end Of Indoor Positionging System

Indoor positioning system has important application value in the environment of large supermarkets, large warehouses and underground parking lots, especially the safety protection and monitoring based on position information. Aimed at the potential market demand, it’s necessary to design the hardware of the indoor positioning system consisting of four transmitters and a receiver. To complete the indoor positioning system, the L band RF front-end should be first designed, which is an important component of the whole system. After fully understanding of the RF front end’s index for the indoor positioning system and the study of the RF link’s structure, a reasonable solution is given.In this paper, the basic principle and the technical index of the filter are analyzed, and the physical meaning of the filter’s S parameters is described. Filter is used to suppress unwanted signals and pass useful signals in the link, which has a vital impact on the performance of the communication system. Beside, according to L band RF front-end’s technical index, choose the super heterodyne receiver architecture, complete parameters allocation and chips selection, including the amplifier, filter, mixer and so on, eventually establish a scheme to design the L band RF channel. The feasibility of the scheme is verified by the ADS behavior simulation, and the circuit design of the RF front-end module is completed. The vibration module which is to provide the LO for upper and lower frequency conversion, it’s designment is also one of the main works of this paper. Based on the technology of phase locked frequency synthesizer, the chip integrated voltage controlled oscillator is used to design the hardware and software of the module.Designed the L band RF front-end, the indicators of the hardware module is verified through a reasonable test platform. Test parameters include link gain, clutter suppression, frequency and dynamic range etc. The result were in accordance with the expected index of the design by data analysis, but also the reliability of the hardware module were verified through the system connectivity test. To sum up, this paper completes the design and implementation of the L band RF front-end based on indoor positioning system.