Abstract: A meter for measuring the relative velocity of an object, including a diplexer for illuminating the object with a beam of microwave energy and for developing from energy reflected from the object a difference signal having a frequency which is proportional to the relative velocity of the object, a phase-locked loop for synchronizing the frequency of an internal oscillator with that of the difference signal and for developing a lock signal when synchronization is achieved, a lock detector and timer and a timer for developing a reset signal from the lock signal, a predetermined period after synchronization is achieved and for developing a latch signal a predetermined period thereafter, a circuit for counting the cycles of the internal oscillator which are developed after the occurrence of the reset signal until the occurrence of the latch signal to develop a sum signal indicative of the relative velocity of the object, and a circuit for displaying the sum signal.

Abstract: Microwave apparatus for detecting the movement of a moving object comprising a Gunn oscillator device having input terminals that are capable of receiving a potential difference which serves to produce a bias current in the device, said potential difference being subject to variations, the device being responsive to a constant potential difference and operative to radiate microwave energy at a first frequency, and further responding to Doppler shifted energy reflected from the moving object and producing a variation in the bias current, an operational amplifier responsive to the potential difference and a reference signal for developing a first signal when the potential difference exceeds the reference signal and a second signal when it is less, a series-pass transistor connected to a source of DC potential and the operational amplifier and being switchable between a conducting and a non-conducting state in response to the first and second signals and serving to maintain the potential difference at a constant