April 1993, Volume 2, Number 1
Radiofrequency and microwave CAD computer programs enabling for signal and yield analysis and circuit optimization have been developed. Program is used both in circuit design and student education.
The semiconductor industry is continuously striving to improve the performance of electron devices and circuits. It implies the need for better understanding of their basic behaviour. However, the miniaturization and complexity of devices led to a breakdown of the analytical models. As a consequence numerical analysis and simulation based on fundamental differential equations has become necessary.
The presented program is devoted to the analysis of general ekvidistant antenna arrays. "The Antenna Array" computes gain, radiation resistance and directivity patterns of antenna systems.
Wavelength division multiplex (WDM) offers a potentially powerful technique for use within optical fibre sensor systems. The paper deals with short description of methodology and a programme code for WDM fiber optic sensor system projecting with use of CAD.
The special program is presented for the demonstration of RF power transistor amplifiers for the purposes of the high-school education in courses of radio transmitters. The program is written in Turbo Pascal 6. 0 and enables to study the waveforms in selected points of the amplifier and to draw the trajectories of the working point in a plot of output transistor characteristics.
An interactive program for simulating light propagation through photonic waveguide structures was developed. From the viewpoint of CAD, two parts of this program are interesting: the channel waveguide editor, and the 3D graphic interpretation of the results. The program is written in MS FORTRAN 5. 1 and runs under DOS on standard PC's. Graphs are drawn in separate windows. It communicates with the user through the mediation of a single command line and keyboard controlled menus. In this contribution, a rough description of the program is given.
The described program generates the forward scattering functions of dielectrics of spherical shape, while the input parameters are: frequency, radius of the sphere and complex refractive index. The part enabling to evaluate the complex refractive index of water in the dependence on frequency and temperature is added.