Fet-teld combination with capacitively coupled output electrode means

In combination:

• a field effect type transistor having drain, gate and source electrodes, said transistor being characterized by an ohmic region of operation in which the drain current varies with voltage and a constant-current region of operation in which the drain current is substantially constant with voltage;
• a transferred electron type device connected to said transistor to form a series current therethrough, said device being characterized by a transfer of electrons from a high to a low mobility sub-band and the formation of domains upon the application of an electric field above a threshold value, said device having a peak current at the threshold voltage and a lower current above the threshold voltage, said lower current being substantially constant with increasing voltage;
• said transistor being biased to operate in said constant-current region such that said drain current is below said peak current and above said lower current of said device;
• means for applying an input signal of a given polarity to the gate electrode of said transistor to increase the drain current to a level equal to or greater than the threshold current of said device causing thereby the formation of domains in said device and a decrease in said drain current to the level of said lower current of said device and producing thereby a shift in the operation of said transistor to said ohmic region and an output pulsed signal of a predetermined voltage gain;
• and
• electrode means capacitively coupled to said device for transmission of said output pulsed signal, the capacitive coupling of said electrode means producing an alternating positive and negative polarity in said output pulsed signal.