QW-CX is a specialised 2D package for the analysis and design of coaxial connectors. A full-wave approach is utilised, allowing for such effects as tapers, gaps in inner connector, re-entrant cavities.
The fields inside a coaxial device are characterized in general by Maxwell equations. In most of the coaxial applications the device is excited by a field of axial symmetry (TEM mode) and due to the symmetry of boundary conditions the axial symmetry of fields is maintained in any transverse section of the device. This happens despite the fact that the fields inside the device are no longer purely of TEM mode but they are composed of TM modes. The Maxwell equations are considered in the system of cylindrical coordinates r and x. Axial symmetry permits to eliminate any derivative of the angle f to obtain a set of 2-dimensional differential equations [2]. In QWCX these equations are being solved using the finite difference time domain (FDTD) method [2],[3]. In the FD-TD method the derivatives with respect to the time and space variables are replaced by finite differences. That is why the considered space should be divided into small sub-domains called cells. Since we consider two-dimensional equations in r, x coordinates the cells are also two-dimensional.
QW-CX has been implemented on the basis of QW-3D, a three-dimensional simulation package by QWED, and a winner of the European Information Technology Prize in 1998. Thus, QW-CX takes full advantage of the graphical user interface and modern programming techniques employed and validated within QW-3D. Moreover, the user experienced with either QW-CX, or QW-3D will find the operation of the other package straightforward.
