Solid state bypass circuit for RF and microwave active circuits

In a circuit of the type having an active component which under normal operating conditions, propagates a signal between an input terminal and an output terminal, and a bypass circuit for bypassing said active component and propagating said signal from said input terminal to said output terminal via a section of transmission line under conditions in which said circuit loses power, said bypass circuit being characterized in that it comprises:

• first and second field-effect-transistors, said first field-effect-transistor being coupled at a first junction located between said input terminal and said active component and said second field-effect-transistor being coupled at a second junction located between said active component and said output terminal wherein said first and second field-effect-transistors provide a first state of substantially high impedance and a second state of substantially low impedance, said first state providing a path under said normal operating conditions wherein said active component propagates said signal from said input terminal to said output terminal, said second state providing a path around said active component under said condition in which said circuit loses power wherein said signal propagates from said input terminal to said output terminal via said section of transmission line;
• and
• first, second, third, and fourth pin diodes, said first pin diode being series coupled between said first junction and said active component, said second pin diode being series coupled between said component and said second junction, said third pin diode being shunt coupled between said first field-effect-transistor and said section of transmission line and said fourth pin diode being shunt coupled between said section of transmission line and said second field-effect-transistor, wherein said first, second, third, and fourth pin diodes prevent output signal feedback at said input terminal.