Abstract: “Actual correlation data” is stored at storage means 38A. Such “actual correlation data” is data representation(s) of correlation(s) between or among distance(s) to object(s) intended to be detected and phase difference(s) of respective reflected wave(s) established with due consideration having been given to reflection of microwave(s) by object(s) (ceiling surface(s), wall surface(s), floor surface(s), etc.) other than object(s) intended to be detected which may be present within area(s) intended to be protected. Distance(s) to object(s) intended to be detected is or are measured, based on such “actual correlation data,” from phase difference(s) of respective reflected wave(s) that has or have been detected.

Abstract: A microwave sensor that transmits a plurality of microwaves having different frequencies to a detection area and performs an object detecting operation based on reflected waves of the microwaves of an object present in the detection area includes object determining means that determines whether or not the object present in the detection area is an object to be detected, based on a moving direction of the object in the detection area.

Abstract: A surveillance camera system is provided with sensors that detect an intruder in a detection area of respectively removed locations connected to a single camera that performs image-taking of the intruder. The detection area is constituted by a wide detection area in which wide-angle image-taking is performed, and sectional detection areas into which the wide detection area is divided and in which enlarged image-taking is performed. The sensor is provided with a control portion that simultaneously performs transmission of an image-taking signal commanding the camera to perform image-taking upon detection of an intruder in the wide detection area, and transmission of an image-taking signal commanding the camera to perform image-taking upon the detection of an intruder in the sectional detection areas, upon detection of the intruder.

Abstract: Detection error resulting from rain, detection error in the case of clear weather, and detection error in the case of rainy weather are included in measurement by a measurement unit disposed in an MW sensor system. The detection error resulting from rain sharply increases as a preset &Dgr;f becomes larger and the detection error in the case of clear weather sharply decreases as the preset &Dgr;f becomes larger. Also, using &Dgr;f as a parameter, a range in which a range where the rate of variability of the value of the detection error resulting from rain with respect to &Dgr;f is low overlaps with a range where the rate of variability of the value of the detection error in the case of clear weather is low is set as the range of the detection error in the case of rainy weather, and the value of the detection error in the case of rainy weather becomes lower than the value of the detection error in the case of clear weather.

Abstract: MW sensor 1 in one or more embodiments of the present invention is equipped with distance identifying means 41 capable of calculating relative distance(s) from the distance identifying means to object(s) at least partially within protected area(s) based on reflected wave(s); moved distance identifying means 42 capable of calculating moved distance(s) per unit time of object(s) at least partially within protected area(s); and object determination means 43 capable of receiving output(s) from distance identifying means 41 and moved distance identifying means 42, and capable of carrying out object detection determination operations(s) such that moved-distance-per-unit-time value(s), at least one of which serves as trigger value for object detection determination, is or are set lower as relative distance(s) to object(s) at least partially within protected area(s) grow smaller.

Abstract: A frequency modulating (FM) transmitter includes a reference frequency generator, a reference frequency divider, a stereo modulation circuit, an oscillator circuit, a program counter, and a PLL frequency synthesizer. The reference frequency generator is for generating a reference frequency. The reference frequency divider is for frequency dividing the reference frequency. The stereo modulation circuit is for frequency modulating audio signals by using one output of the reference frequency divider to supply resultant stereo modulated signals as FM signals. The oscillator circuit is for generating carrier waves to transmit the FM signals. The program counter is for frequency dividing the carrier waves into variable frequency components. The PLL frequency synthesizer has a phase comparator circuit for comparing the variable frequency components output from the program counter with another output of the reference frequency divider.