Split cascode line amplifier for current-mode signal transmission

A low frequency signal transmission system, comprising a split cascode amplifier:

• a front end common emitter or source amplifier portion of said split cascode amplifier which receives a low frequency voltage signal, said front end amplifier converting the voltage signal into a current signal at its output and having a high output impedance;
• a two conductor transmission line in which the conductors are in close proximity to each other, one end of said line receiving the current signal from the front end amplifier and delivering it to a second end at a remote location;
• a back end common base or gate buffer circuit portion of said split cascode amplifier, which receives the current signal from the second end of said transmission line and converts it into an output voltage, said back end buffer circuit having an input impedance which is significantly lower than the output impedance of the front end amplifier;
• wherein the front end amplifier includes a junction field effect transistor, a pate resistor, and a source resistor;
• wherein the gate resistor and source resistor operate in unison to set an operating point of the junction field effect transistor, and the source resistor provides a substantial level of negative feedback;
• and
• wherein the level of negative feedback stabilizes a drain current operating point of the junction field effect transistor due to variations in operating parameters of the transistor.