Ft doubler
The ft doubler circuit is a transistor amplifier topology, invented by Carl Battjes, that has a current gain of 2 even at the transition frequency of the transistors that are used in the circuit.
It is used heavily in Tektronix instruments and several Tektronix integrated circuits implement this approach.
- US Patent 3,633,120 Filed Sept. 16, 1970 / Granted Jan. 4, 1972