Injection Locking And Its Applications To Multi-Frequency Oscillators

With the rapid development of modern communication system, the demands for functionality and portability of wireless devices are obvious. Therefore, applications and researches of reconfigurable and multifunctional or multiservice communication systems become hot topics. Considering a multifunctional transmitter-receiver system, the key issue lies in the implementation of multiple stable carriers. The common technique to stabilize the carriers is the use of multiple phase locked loops, where each loop stabilizes a carrier. However, the complex scheme results in design difficulties, high power consumption and cost.Nevertheless, when using the injection locking to stabilize carriers the advantages such as easy layout in planar version, low sensitivity to external interference, low DC power consumption, and high operation frequency make it attractive and potential to be used in communication systems.Combining with injection locking technique, this thesis focuses on applying the injection locking to multi-frequency oscillators. The contributions and innovations of this study are as follows:(1) A thorough analysis has been performed in-depth to study the mechanism and the influence factors of injection locking as well as the locking process. Based on the research of the feedback model of injection-locked oscillator, the locking equations that describe all injection conditions are also given.(2) The mathematical model of locking process is constructed, hence the simulation of the locking process can be conducted. Experimental results showed good agreement with the simulation results, thus validated the accuracy of the model.(3) Analytical study and experimental validation of the harmonic or nonlinearity enhancement mechanism of an active component has also been performed.(4) Based on the frequency pulling between two oscillators, a novel dual frequency oscillator scheme using one phase locked loop has been proposed. Demonstration on such a scheme shows simple topology and great design flexibilities.