Frequency response analysis of a 1:1 transmission line based transformer

Abstract

A theoretical approach to study the frequency response characteristics of a 1:1 transmission line based transformer is described. The frequency and impulse response were calculated to take into account signals that inevitably appears in outside space around and between the transmission lines. Experimental confirmation of the deduced frequency response function was made for a prototype transmission line based transformer where semirigid coaxial cables were used as transmission lines. Good agreement was obtained between the theoretical and experimental results in the 50 MHz–3 GHz frequency range. A 3 dB bandwidth of the transformer was obtained from 20 MHz to 1 GHz. The theory described here would be useful in the design of actual high frequency transformers.

High-voltage isolation transformer for sub-nanosecond rise time pulses constructed with annular parallel-strip transmission lines

“…As described in a previous paper, a small part of the signal being transmitted with the transformer also escapes into the space inside of the annular transmission line. 6,7 Then those escaped signals invariably appear in the transformer, leading to attenuation of the output signals.…”

“…The fundamental idea and procedure leading to this equivalent circuit have been described in detail in previous articles. [6][7][8] From this circuit, the frequency response function of the transformer…”