| Summary: | 碩士 === 國立海洋大學 === 電子工程學系 === 83 === The return loss, insertion loss, coupling flatness and
directivity are important parameters to be taken into account
in the design of directional couplers. Recently, two methods
have been proposed to improve the performances of the direc-
-tional couplers. Firstly, the coplanar waveguides (CPWs) are
employed to serve as the transsmission lines. Secondly, a di-
-electric overlay is added to the upper surface of the coupler.
In the present study, both of the methods are imployed to
achieve better microwave performances. In the present study,
the waveguiding characteristics of the coupled CPWs with and
without dielectric overlay are ana- lyzed for the first
time. Next, the field patterns of the conductor-backed
coupled CPWs are plotted by using the conformal mapping
techniques. Moreover, three CPW directional couplers are
designed and implemented. Finally, their microwave charac-
-teristics are measured and compared with the results from the
computer simulation.
|
|---|
