The STLT-an ultra-wideband high-ratio pulse transformer

The series transmission line transformer (STLT) heralds from six decades ago, recasting transmission line technology with enabling qualities. Functionally similar to broadband Guanella-type transmission line transformers, the STLT dramatically simplifies the physical complexity and can be scaled to a vast range of size or power. The modular construction allows for a high impedance ratio, with 1000:1 easily realizable. Properly constructed, the STLT performance is limited only by the constraints of the transmission line. We present here the generalized construction of any STLT, performance data of various prototypes, and demonstrate one particular embodiment in a printed circuit package, scaled for driving electro-optical devices. Specifications are: 50-ohm to 3.125-ohm impedance ratio (16:1), 14-kV maximum voltage, 100-ps step response (rise time), and 1-inch square dimension.