Abstract: A microwave or ultrasonic detection system is disclosed which has a voltage controlled transmitter oscillator. The output of the transmitter oscillator is transmitted into a designated area from a transmit antenna and is reflected by objects in the area and received by means of a second antenna. The reflected signal is phase compared to the output of the transmitter oscillator. A phase error signal is generated that varies with the phase difference, and this signal is input to the transmitter oscillator to cause the frequency of the oscillator to vary in such a way to produce a null phase difference. When the position of an object which reflects the transmitted signal is changed, the length of the propagation path for the signal changes which produces a phase error signal. This phase error signal in turn causes the transmitter oscillator to shift frequency.

Abstract: A segmented voltage function is generated at the output of a primary differential amplifier having an input voltage connected to the noninverting terminal. As the input voltage increases at the noninverting amplifier input, the output increases with the same slope until a voltage as sensed at the inverting input of the amplifier equals a first breakpoint. The inverting input to the primary differential amplifier connects to a feedback circuit that also includes a plurality of secondary differential comparator amplifiers coupled to a voltage ladder network. Each of the secondary differential amplifiers has a noninverting input connected to a separate voltage on the ladder network. The inverting input of each of the secondary differential amplifiers is connected to a feedback loop.