A monolithic substrate contains an integrated circuit comprising an amplifier having input and output, a mixer and a hybrid coupler for coupling the amplifier to the mixer. The door locking system includes, but is not limited to a mechanical door opening safety catch and a warning unit configured to generate a first warning signal that is exclusively suppressed by a manual activation of the mechanical door opening safety catch. A local on chip state machine may be used to accelerate the programming rate, and there may be a state machine per memory bank.