Studies On Multiple-Source Microwave Photonic Filters And Their Applications In Radio-over-Fiber System

In this thesis, we do researches on multi-source microwave photonic filters of different kinds and their applications in radio-over-fiber system, and demonstrate their features theoretically and experimentally.At the beginning, introduces on microwave photonics, microwave photonic filter are given, which are focus on their development, applications and recently research situation all over the world. Then, the principle of microwave photonic filter is explained in detail, including single-source microwave photonic filters and multi-source microwave photonic filters. Some concepts about microwave photonic filters are also included in this chapter.In the following parts, three kinds of microwave photonic filters are analyzed specifically. First, one of these three microwave photonic filters is based on independent laser array. Theory principles and formulas are analyzed, as well as the simulation using MATLAB. Some variables, such as length of the fiber, wavelength of the lasers, number of the lasers, different length and power between the lasers, are changed to see the results of the filters. And some related experiments are also implemented to verify theoretic results.The second kind of the multi-source microwave photonic filter is based on the modulator. Theories and experiments are both used to prove the performance. The dc-bias and the frequency of the radio applied to the modulator are specifically analyzed. A phase modulator is employed in this experiment, and the negative microwave photonic filter is achieved which has a big application in reality.The last kind of multi-source microwave photonic filter is formed by slicing the broadband optical source using a Mach- Zehnder interferometer. The interference can be seen as the samples with different weights distributing as a gauss-like light. Lastly, this tunable single resonance microwave photonic filter with high Q is applied in radio over fiber system to demultiplexed the multiplexed subcarriers. One of the subcarriers lies in 900MHz representing the GSM signal, and the other one is 2.4GHz representing the WLAN signal. The results of the filtering are given.