PLL Circuit Design of Level Radar

Abstract

Level radar is used to measure the distance of liquid level in chemical tanks, and thereby counts the amount of the content. The content of this thesis is based on the principle of FMCW radar to design and implement the level radar circuits. FMCW the signal continuously transmits to the target with frequency modulated and the target distance can be deduced from the received signal. The radar RF signal is generated from a phase-lock-loop with stabled frequencies then through a multiplier to the antenna for radiation then the radar received signal is mixed with the transmitted signal to give an intermediate frequency signal for calculating the distance. The capacitor of chemical tanks is then derived.
Chapter1 introduces the radar system of level meter and the system structure. Chapter 2 gives the description on the FMCW radar principle and the schematics of level radar. Chapter 3 then describes the characteristics of each component, circuit design, layout, circuit implementation, and measurement results of the circuits involved in the level radar. In Chapter 4 , the test and measurement results of each circuit in the system, and the measured results of a distant object are presented. Chapter 5 is the conclusion to discuss the circuit design and measurement results.