Study. Waveguide Duplexer

This thesis provides the technique of waveguide duplexer design. On the basis of classical theory, it presents some novel structures and techniques to attain spurious-free characteristic.Duplexer is a type of microwave device which is vitally important in communication systems. It splits signals to two passband, reciever and transmitter, respectively. Its performance can directly influence the character of the whole system.Firstly, it gives out two novel structures with spurious-free characteristic which called width diversification technique and cornerwise technique. In the width diversification technique we combine a series of desonators together. These desonators share same foundamental mode frequency but different higher modes frequency. In this way, a filter with spurious-free characteristic can be designed out, so does a duplexer. In the connerwise technique, by rightly arrangement of windows, we give simulation of foundamental mode only. Both of these two techniques have good thereotical result.Then, it designs a type of duplexer with passbands at 14.7GHz and 15.2GHz respectively. This duplexer is low-loss, mass productable and has spurious free characteristic at 35GHz which meets the engineering requirement. This type of duplexer is designed, produced, measured and put into engineering use.