Abstract: A motion detector combines an FCC approved homodyne pulsed range-gated radar (“RGR”) detector (10) and a PIR detector (158). Narrow microwave pulses are transmitted at a predetermined pulse repetition frequency (“PRF”) and the pulses are reflected by a target. The RGR detector senses the presence of moving human sized objects within predetermined ranges. Moving objects beyond the ranges are not sensed. The RGR detector employs a pulsed microwave oscillator (12) that is triggered by a system clock (14) and immediately retriggered after a 3 to 100 nanosecond delay (20). The duration of each pulse is 3 to 20 nanoseconds with a half-sine envelope shape. The RGR employs a homodyne detector (36) and shares an antenna (38) with the transmitter. The receiver range is determined by the delay imposed between the transmitted pulses, the first being a transmitted pulse and the second being a local oscillator pulse. Each received 5.8 GHz pulse is mixed down to a baseband by the homodyne detector.

Abstract: A transmission path is monitored for its suitability for transmission of digital data by transmitting over the transmission path a video test signal which includes a horizontal sync pulse and at least one half-cycle of a generally sinusoidal pulse occurring at a predetermined time after the sync pulse, the generally sinusoidal pulses being inverted in alternate lines or alternate fields of the video test signal. The signal received at the other end of the transmission path is displayed on an oscilloscope-type CRT device having its horizontal sweep triggered by the horizontal sync pulse, so as to superimpose the alternate generally sinusoidal pulses. The configuration of the generally eye-shaped area resulting from such superimposition depends on the suitability of the transmission path for transmission of digital data.