论文部分内容阅读
内导体接近的屏蔽结构的对绞线路与以前的市内电缆的目的不同,能用作定向耦合器。为得到强耦合,本论文研究了内导体非常接近的线路。特别在小功率使用而用极细线来做的话,那么为保持内导体的间隔,在制造上不得不使用第二种介质,结果就成了不均匀介质。对这种屏蔽形对绞线路,作为由准TEM模近似而作出的解法,可用保角变换方法来分析。同时,本文也说到了有关线路常数的测定方法及根据TEM近似而作出的定向耦合器的限制。求出的近似式既能适用于10db以下的强耦合线路的设计,也能满足试制3db,5db用线路。试制线路的定向耦合器是有实用可能的,并能期待在VHF,UHF频带得到应用。
The intertwined shielded structure of the inner conductor has a different purpose than the previous city cable and can be used as a directional coupler. In order to obtain strong coupling, this paper studies the very close lines of inner conductors. In particular, the use of very low power to do with very thin lines, then to maintain the spacing of the inner conductor, the manufacture had to use the second medium, the result has become a non-uniform medium. For such a shielded twisted pair line, a solution made by quasi-TEM mode approximation can be analyzed by conformal mapping. At the same time, this article also talked about the method of determining the line constant and the directional coupler based on the TEM approximation. The approximate formula can be applied to the design of the strong coupling circuit below 10db, but also to meet the trial 3db, 5db lines. It is practically possible to try out the directional coupler of the line, and it can be expected to be applied in the VHF and UHF bands.