Abstract: Apparatus and system for controlling the gate threshold settings of MNOS memory devices is disclosed. Positive or negative pulses depending on turn-on or turn-off of relatively large amplitude and relatively low frequency are applied to the gate of the MNOS device whose threshold is to be set and to whose gate a bias value equal to the desired setting has been applied. A feed back circuit, in response to the change in current conduction condition of the test MNOS device caused by the application of the pulses, reduces the magnitude of the pulses to a low value as the gate threshold value reaches the desired set value.

Abstract: A matched transmission line coupling an RF generator to an antenna and receiving Doppler altered reflected signals from the antenna. A pair of diodes coupled to the transmission line 90 electrical degrees apart at the RF frequency and oppositely poled so that the RF signal from the generator and the reflected signal from the antenna are heterodyned in each diode to produce a heterodyne signal which is in phase. The heterodyne signals are band limited, filtered and passed through threshold detectors separately to provide separate in phase pulses which are applied to a coincidence gate to provide an output. Amplitude modulation is rejected because it produces out of phase signals and frequency modulation is rejected because the transmission line is substantially flat. The RF generator may be frequency modulated and the output of the coincidence gate is applied to a shift register to insure the triggering thereof by only a true Doppler signal.