| 摘要 |
A microwave detector for detecting faint detection target microwave signals is constructed from a heterodyne-type reception portion equipped with an antenna for picking up microwave signals, a local oscillator for repeatedly carrying out a sweep operation, and a mixer for frequency mixing the output from the antenna with the output from the local oscillator, wherein the heterodyne reception portion outputs detected wave signals based on the output from the mixer; a digital processing portion which receives the detected wave signals outputted from the reception portion, wherein the digital processing portion is designed to output a High pulse when the level of the detected wave signals reaches or exceeds a prescribed reference level, and a Low pulse when the level of the detected wave signals is below the reference level; a sweep control portion for controlling the sweep operation of the local oscillator based on the High and Low pulses outputted from the digital processing portion; and a judgement portion for judging whether or not a detection target microwave signal has been detected based on at least one measured or calculated quantity such as the total time High pulses are outputted by the digital processing portion, the total time a sweep stop is carried out by the sweep control portion, the total time required to complete a sweep, or a relationship between the total time High pulses are outputted and the total time Low pulses are outputted (e.g., the duty thereof). Further, a separate judgement-use digital signal generating portion may be provided to enable sweep control and detection judgements to be carried out by separately generated digital signals, and the detection accuracy can be further improved by dividing each sweep into a plurality of sampling regions and by providing a signal discrimination portion or signal discrimination function.
|
