Abstract
In this thesis, first ( the 2nd chapter ) we introduce the theories of the quarter-wave transformers and Chebyshev transformers. We also discuss the meanings of the approximation used in the derivation and the features of the characteristic impedance of quarter-wave transformers. In the 3rd chapter, we design the structures of different impedance ratios of 3-section and 4-section Chebyshev transformers. We use the HFSS ( High Frequency Structure Simulator ) to simulate the frequency response of these structures, and have discussions on the results of the simulations. We manufacture the chosen structures and use the HP8510 network analyzer to proceed the cold tests. We compare the results of the cold tests with those of the simulations. The results of the simulations show that Chebyshev transformers do have the extremely low-reflection responses around the designed central frequency. In the results of the cold tests, however, there are not the same responses in the same frequency range. We can improve the experiment results by modify the mismatch of the load, or use other methods to do the cold tests.