It is often the case, that an Engineer is required to simulate environmental effects on a device manufactured by a third party.  In such an event, the first issue that is faced by the Engineer, is a lack of access to the manufacturing process that created the third party device in the first place.  In this article, it is shown how to overcome this first issue, and reverse engineer a sufficiently representative base device, simply from the manufacturer’s specification sheet.  Once a satisfactory device has been fabricated, it can be used in the required simulation to analyze any effects of interest.  In this particular case, we will demonstrate the damaging effects of irradiating a 2N2222A bipolar transistor with a proton flux and compare the simulated results with other similar measured results.

In connection with the reduction in the size of electronic elements and the increase in operating frequencies, it becomes necessary to transmit signals between the nodes of the circuit using micro strip transmission lines. . Micro strip is similar to strip line transmission line except that the micro strip is not sandwiched, it is on a surface layer, above a ground plane. A strip line circuit uses a flat strip of metal which is sandwiched between two parallel ground planes. The insulating material of the substrate forms a dielectric. The width of the strip, the thickness of the substrate and the relative permittivity of the substrate determine the characteristic impedance of the strip which is a transmission line. As shown in the diagram, the central conductor need not be equally spaced between the ground planes. In the general case, the dielectric material may be different above and below the central conductor.