Abstract: Certain exemplary embodiments provide a method comprising sensing an intruder within a predetermined vicinity of a Free Space Optical Communication (FSOC) system; and reducing an emitted power of the FSOC system. Certain exemplary embodiments provide a system comprising a Free Space Optical Communication (FSOC) subsystem; a sensor adapted to detect an intruder within a predetermined vicinity of the FSOC subsystem; and a switch adapted to reduce an emitted power of the FSOC subsystem, said switch coupled to said sensor.

Abstract: A method and apparatus for communicating simultaneously at the same frequencies includes two or more conductor-backed, spiral antennas that have been shown to exhibit linear polarization. To permit simultaneous transmission on the same frequencies, two of the linearly polarize, conductor-backed spiral antennas can be spaced vertically and be oriented so that the feed points of one antenna are orthogonal to the feed points of the second antenna. Since the specifically designed spiral antennas will be both transmitting or both receiving at orthogonally arranged polarizations, the antennas will not interfere with each other, even though communication is upon substantially the same frequencies.

Abstract: An antenna arrangement comprises at least two antenna loops disposed and overlapping in a plane to define a detection region adjacent thereto in which the antenna loops transmit and/or receive electromagnetic signals and through which a wireless article may pass. The antenna arrangement may be coupled to a processor and/or utilization system for performing a desired function.

Abstract: Methods for aligning a satellite reflector with an antenna. One method includes the use of an antenna-alignment device to orient the centerline of an antenna in a desired azimuth, elevation and skew orientation. Another method includes the use of an antenna alignment device that is attached to the antenna and can be used in conjunction with a set top box attached to the antenna without the installer having to make trips between the antenna and the television to which the set top box is also attached. Yet other methods include the alignment of an antenna with a satellite wherein the antenna is supported by an adjustable mounting bracket.

Abstract: This invention describes a method, an apparatus, and a system for optimizing antenna performance by remotely adjusting the plumb-to-level (absolute measurements with respect to true vertical) and the compass heading (absolute compass heading direction with respect to magnetic North) of one or a plurality of communication antennas by electromechanical means. Until now, only fixed, manual adjustments referenced to points on the tower that are assumed to be accurate, but are not, can be made. Furthermore, antenna optimization that is accomplished by solely adjusting the tilt of an antenna is limited. And, since azimuth adjustments for antenna sectors are difficult to adjust manually and are not available by electromechanical means, site planning personnel have not been able to accurately compensate for changes in tower and site parameters.

Abstract: The present invention disclosures a method for aiming antennas during the installation of microwave communication systems. By computerized link quality monitoring mechanism, the software of the computer system can monitor the link quality of the link during the aiming of the installation. The link quality comprises the performance of data communication status, and the signal strength and noise tests result. By aiming and installing the antenna at the best link quality direction, the microwave communication system will work at best performance status. The software system also will guide the installer to follow certain procedures and finally affix and aim the antenna to the best direction. There are no extra equipments, such as high cost spectrum analyzer needed. And also, no super high-skilled microwave experts are needed to install and setup the microwave communication system.

Abstract: Vehicle security systems comprise at least one addressable transponder for communication with at least one base station. Each transponder and base station comprises a steerable directional antenna having an antenna azimuth sensor. Transponder and base station antenna azimuths assist in locating a vehicle carrying a transponder and allow near real-time estimation of vehicle heading. Base station networks facilitate location, tracking and/or interception of vehicles within a network geographic area. Use of multiple effective transmission ranges for transponders and/or base stations improves the accuracy of vehicle location.

Abstract: An alignment device for aligning an antenna with a satellite. In one embodiment, the device includes a digital compass to provide an azimuth reading of the antenna when the device is removably affixed to the rear surface of the antenna reflector. In another embodiment, the device includes a first digital level that provides an elevation reading of the antenna when the device is affixed to the rear surface of the antenna reflector. Another embodiment includes first and second digital levels that cooperate to emit a skew signal that is indicative of the skew orientation of the antenna when the device is affixed to the antenna. In yet another embodiment, a speaker is provided adjacent to the antenna to receive a series of tones transmitted by a transmitter that is placed adjacent to a television that is attached to a set top a box that is attached to the antenna.

Abstract: An antenna that has an alignment device for aligning an antenna with a satellite integrally attached thereto. In one embodiment, the device includes a compass for orienting the antenna at a desired azimuth setting. In another embodiment, the device includes a compass and a level for orienting the antenna at a desired elevation. Another embodiment includes a compass and first and second digital levels that cooperate to emit a skew signal that is indicative of the skew orientation of the antenna when the device is affixed to the antenna.

Abstract: Car antenna seat including a main body composed of two casings, a transparent antenna rod and a pivot rod. Several LED are respectively disposed on upper and lower faces of a fixing plate disposed in the main body. Transparent decorative boards are disposed on the casings, permitting light to pass therethrough. The transparent antenna rod is fixed on the main body. An antenna is fitted around the antenna rod. The pivot rod is pivotally connected with the bottom of the main body. A bulb set is disposed in a base of the antenna rod. The bulb set includes a color-changeable bulb and a controlling circuit board. The color-changeable bulb is controlled by the circuit board to flicker and change the color, whereby the transparent antenna rod can present different colors or flicker. By means of adaptable screw, the bottom end of the pivot rod is locked with a holder or fixing tray. The car antenna seat emits light to achieve a warning effect and a decorative effect.

Abstract: An antenna arrangement comprises at least two antenna loops disposed in two intersecting planes disposed at an angle to define a detection region in which the antenna loops transmit and/or receive electromagnetic signals and through which an object may pass. Each antenna loop includes a portion disposed in each of the two planes, and the antenna loops overlap at least in part in each of the two planes. The antenna arrangement may be coupled to a processor and/or utilization system for cooperating therewith for performing a desired function.

Abstract: An antenna array comprises a plurality of antenna loops disposed to define a portal or passageway or other detection region in which the plural antenna loops transmit and/or receive electromagnetic signals. A processor coupled to the plural antenna loops processes at least the received signals and/or transmitted signals. The plural antennas may be arrayed in a rectangular array, on hanging flexible substrates or other suitable arrangement, and may be coupled to the processor by a filter or selective switch. The processor may be coupled to a utilization system for cooperating therewith for performing a desired function.

Abstract: A satellite antenna alignment device is provided which includes a base plate having a semi-globular-shaped member of dome secured thereto and extending upwardly therefrom which defines a sealed compartment which is filled with a liquid or gaseous medium. An indicator is positioned within the sealed compartment. The exterior surface of the dome is provided with elevational and skew angle indicia thereon. The device enables the antenna to be quickly and easily elevated to the proper elevation and skewed to the proper skew angle.

Abstract: An apparatus and a method for orienting an antenna to a transmitter, and an antenna using the apparatus are disclosed. The apparatus for orienting an antenna toward a transmitter, which is used with an antenna, comprises a shadow generating means fixedly mounted to the antenna so as to generate a shadow of the sun, and target indicating means for specifying a target point on a reflector, at which a predetermined portion of the shadow generated by the shadow generating means should be positioned when the antenna is correctly oriented toward the transmitter.

Abstract: An alignment device for aligning an antenna with a satellite. In one embodiment, the device includes a digital compass to provide an azimuth reading of the antenna when the device is removably affixed to the rear surface of the antenna reflector. In another embodiment, the device includes a first digital level that provides an elevation reading of the antenna when the device is affixed to the rear surface of the antenna reflector. Another embodiment includes first and second digital levels that cooperate to emit a skew signal that is indicative of the skew orientation of the antenna when the device is affixed to the antenna. In yet another embodiment, a speaker is provided adjacent to the antenna to receive a series of tones transmitted by a transmitter that is placed adjacent to a television that is attached to a set top a box that is attached to the antenna.

Abstract: An apparatus and method for aligning the antennas of two transceivers of a point-to-point wireless millimeter wave communications link. A narrow band oscillator power source is substituted for the signal transmitting electronics associated with a first antenna and a power detector is substituted for the signal receiving electronics associated with a second antenna. In preferred embodiments after a first alignment procedure is performed, the procedure is repeated with an oscillator power source connected to the second antenna and a power detector connected to the first antenna. In other preferred embodiments the antennas are pre-aligned using a signaling mirror or a narrow beam search light or laser. After the antennas are aligned the transceiver electronics are reconnected. In preferred embodiments the communication link operates within the 92 to 95 GHz portion of the millimeter spectrum and provides data transmission rates in excess of 155 Mbps.

Abstract: Equipment and methods for aligning the antennas of two transceivers of a point-to-point wireless millimeter wave communications link and keeping them aligned. Each of two communicating antennas is equipped with a telescopic camera connected to a processor programmed to recognize landscape images. The processors are programmed to remember the pattern of the landscape as it appears when the antennas are aligned. Each of the cameras then view the landscape periodically or continuously and if the landscape in view changes by more than a predetermined amount a signal is provided to indicate a misalignment. An operator can then take corrective action or alternatively the antenna system can be configured for remote or automatic realignment based of feedback from the camera.

Abstract: A label includes an inlay including a conductive material. A sheet is fixed over at least a portion of the inlay, and has a first surface and a second surface. A protective material is fixed to the first surface of the sheet, and an aperture extending through the protective material and sheet is positioned over at least a portion of the conductive material to define a protective cavity. A device is disposed in the protective cavity, and electrically connected to the conductive material, wherein the protective cavity surrounds the device. In another aspect of the present invention, the protective material is expandable from an unexpanded height to an expanded height, and the expanded height is at least 10% greater than the unexpanded height.

Abstract: A point-to-point, wireless, millimeter wave communications link providing data transmission rates of over 1 billion bits per second (more than 1 Gbps) at ranges of several miles during normal weather conditions. In a preferred embodiment a communication link operates within the 92 to 95 GHz portion of the millimeter spectrum. A first transceiver transmits at a first bandwidth and receives at a second bandwidth both within the above spectral range. A second transceiver transmits at the second bandwidth and receives at the first bandwidth. The transceivers are equipped with antennas providing divergence of less than 10−4 steradians so that an almost unlimited number of transceivers can use the same spectrum. In a preferred embodiment the first and second spectral ranges are 92.3-93.2 GHz and 94.1-95.0 GHz. During very bad weather conditions this data link will not provide a 10−10 bit-error rate and 99.999% availability.

Abstract: An automatic antenna direction controller which automatically turns an antenna rotor and connected antenna to a desired direction which is preselected by a pointer knob. A dual use meter needle is utilized by action of the pointer knob to select the azimuth of an antenna and to indicate the actual azimuth. A multi-color status LED indicator indicates different colors corresponding to the percentage of rotational completion completed. Control is offered by onboard circuitry for automatic brake release and setting, preset electronic end points for rotation limits, overshoot protection, and an unstick routine. Optional control can also be managed by an outboard computer through an RS-232 connection.

Abstract: A heated antenna system includes an antenna having a reflecting surface and a heater associated with the reflecting surface. A storage capacitor is connected with and provides power to the heater. An electronic control system is electrically connected to the storage capacitor. The electrical control system charges and monitors the storage capacitor and issues a status signal indicative of a status of the storage capacitor.

Abstract: A satellite antenna alignment device is provided which includes a support which may be selectively removably mounted on the underside of the support arm of the antenna. The alignment device includes a pivotal plumb bob having a chart positioned therebelow which is provided with skew angles and elevation angles to enable the antenna to be quickly and easily elevated to the proper elevation and skewed to the proper skew angle.

Abstract: An alignment tool and method of making and using an alignment tool including a transparent substrate having indicium thereon to aid in aligning the antenna with an azimuth. The tool includes a transparent substrate, a series of indicia, and a receiving portion adapted to receive a mounting structure of the antenna. The tool preferably includes a bearing indicium used during the making of the tool that represents an azimuth along which the antenna is to be aligned, a reference indicium used during the alignment of the antenna to align the tool with the antenna, and a landmark indicium used during the alignment of the antenna to align the tool with a distant landmark. The alignment tool is constructed using a topographical map that includes geographic markings for the antenna, the azimuth corresponding to the transmission direction of the antenna, and a distant landmark.

Abstract: A monitoring system incorporates antennas that transmit signals at predetermined frequencies; the transmitted signals are received by tags located in the active monitoring area of the antenna which then transmit signals back to the antenna. The antennas are tuned to each desired frequency prior to driving the antennas to transmit at the desired frequency. The system transmits a range of frequencies in a sequence that uses overlapping frequency steps. The monitoring system is also constructed having a variable configuration resulting in the ability to be reconfigured under program control to conform to varying system requirements. The integrated monitoring system employs programmable formats for reconfiguration such that upon program input from a host computer the system can assume predetermined configurations to conform to the particular tasks for the specific application.

Abstract: An apparatus and method for ensuring proper antenna position of a cordless communication device having a retractable antenna, including a detector such as a light sensor or induction coil for detecting the antenna position, and an indicator for providing audio and/or visual indication of the antenna position.

Abstract: An antenna for installation in a radio communication device, namely a transmitter and/or receiver, has a substantially cylindrical exterior surface and includes at one end a light source which is a light-emitting diode encapsulated in a housing and electrical connection elements including rings disposed around the cylindrical surface, a light diffusing part at the other end, and an elongated light guide therebetween. The rings are in electrical contact with respective lighting contacts of the communication device when the antenna is installed in the communication device.

Abstract: An antenna for receiving a satellite broadcast can adjust orientation at higher precision than a method based on a compass and a level, without being influenced by environmental magnetic field generated by magnetic body or electromagnetic sources, can perform adjustment of orientation even before a radio wave from the satellite is not catched, can monitor the deviation during the fixation of the antenna orientation to improve the workability in adjustment of antenna orientation. The antenna for receiving a satellite broadcast has a reflector for reflecting a radio wave from a satellite on a reflecting surface for convergence and a receiving portion for receiving the radio wave reflected by the reflector. The antenna further includes a light blocking portion forming a shadow by the sun light, a scale determining a direction of the sun by the shadow formed by the light blocking portion. The light blocking portion and the scale are provided at an upper end portion of the reflector.

Abstract: A satellite antenna alignment device is described for use with a satellite antenna to enable the satellite antenna to be aligned with respect to a particular satellite. The alignment device is operatively secured to the support arm of the satellite antenna and includes a compass for indicating the directional position of the support arm and also includes a clinometer.

Abstract: A collapsible dish antenna mount (1) for a vehicle roof, has a mast (11) received in said roof and extending into the vehicle. The dish antenna (3) is secured to said mast (11) by a mechanical linkage operable from within said vehicle such that the dish antenna (3), when raised, may be adjusted in both azimuth and elevation. When not in use, the antenna mount (1) can be folded to reduce windage.

Abstract: Physically small quadrifilar helix antenna systems capable of providing a positive gain, quasi-hemispherical antenna pattern over a relatively broadband frequency range in the L-Band frequency band. The antenna systems according to the present invention generally comprise a quadrifilar helix antenna and at least one antenna feed network, and may further comprise matching means for improving the broadband frequency performance of the antenna. In a preferred embodiment, the elements of the quadrifilar helix antenna which form each bifilar helix are short-circuited at their distal ends, and energy is fed to and induced from the antenna via receive and transmit 90.degree. hybrid couplers which are electrically connected to the bifilar loops of the quadrifilar helix antenna.

Abstract: An illuminant-mounted antenna includes a rod-shaped antenna element, an illuminant mounted on top of the rod-shaped antenna element, and lighting means for lighting the illuminant by high frequency energy generated on the rod-shaped antenna element when a portable transceiver is operated. The lighting means includes a high frequency detecting diode and an inductive element. One end of the high frequency detecting diode and one end of the inductive element are connected in common to the top of the rod-shaped antenna element, and the other end of the high frequency detecting diode and the other end of the inductive element are connected to both ends of the illuminant.

Abstract: An antenna mounting system including at least one level indicating device mounted on a mast of the antenna for providing a constant indication of the alignment of the mast relative to a selected orientation of the mast with respect to the horizon.

Abstract: A new and improved system which facilitates the use of sunlight and sun shadows to optimize site surveys and the placement of satellite dish antennas and the like in order to provide unobstructive reception from a satellite transmitter and, further, facilitate alignment of the dish relative to a satellite.

Abstract: A proximity detector detects objects which may interfere with a wireless antenna beam. The proximity detector includes infrared sensors, sonar detectors, motion detectors and optical devices to determine a range and bearing of objects that may interfere with the antenna beam.When an object may be harmed or interfere with the antenna beam, an alarm may be activated to warn the user and/or the object of potential harm from the electro-magnetic energy transmitted by the directed antenna. Also, based on the proximity detector's outputs, an antenna beam pattern may be changed to reduce the power at the object or the transmitted power may be reduced to prevent harm to the object.

Abstract: This invention discloses an improved construction for portable disk antenna. This construction mainly comprises a disk antenna body, an outer member, an inner member, and a base. The outer member may rotate over 360 degrees about a first axis relative to the base. The inner member is rotably fitted into the outer member. The disk antenna body is connected to the inner member such that the disk antenna body, together with the inner member, can be rotated with respect to the outer member within an appropriate angular range about a second axis perpendicular to the first axis. This invention is characterized by further comprising an azimuth calibrating device having an azimuth calibration scale formed thereon for calibrating the azimuth deviation of the disk antenna body before use according to the indication of a compass; and an elevation calibrating device having an elevation scale formed thereon for calibrating the elevation deviation of the disk antenna body according to the indication of a level instrument.

Abstract: An improved Global Positioning em antenna adaptor allows fixed antenna height measurements by removably attaching an adaptor plate to a conventional surveyor's tripod. Antenna height is controlled by an antenna boom which is a fixed length rod. The antenna is attached to one end of the boom. The opposite end of the boom tapers to a point sized to fit into a depression at the center of survey markers. The boom passes through the hollow center of a universal ball joint which is mounted at the center of the adaptor plate so that the point of the rod can be fixed in the marker's central depression. The mountains of the ball joint allow the joint to be moved horizontally in any direction relative to the tripod. When the ball joint is moved horizontally, the angle between the boom and the vertical changes because the boom's position is fixed at its lower end. A spirit level attached to the rod allows an operator to determine when the boom is plumb.

Abstract: A satellite dish antenna for receiving a broadcast signal from a satellite includes a low noise block which receives the signal reflected from the dish and provides a human-perceptible guidance signal, such as a sequence of beep tones, to aid an individual in properly orienting the satellite dish with respect to the satellite. A time interval between the beep tones is varied in dependence on the strength of the broadcast signal received at the low noise block. A circuit for providing the guidance signal is activated by a non-contact switch, such as a magnetic lead switch. A magnet is movably mounted on the surface of the low noise block for selectively activating and deactivating the guidance signal circuit.

Abstract: An active deflection compensator for use with an antenna system that comprises a linear scanner ridge that projects into a waveguide cavity coupled to an antenna array. Linear actuators are coupled to the linear ridge at opposite ends thereof and adjacent its center. Transducers are coupled to the linear ridge at opposite ends thereof adjacent the actuators that are adapted to provide signals indicative of the linear and angular displacement of the linear scanner ridge. A transducer is disposed adjacent the center linear actuator that is adapted to provide signals indicative of the amount of bending of the linear scanner ridge.

Abstract: A satellite dish antenna for receiving a broadcast signal from a satellite includes a low noise block which receives the signal reflected from the dish and provides a human-perceptible guidance signal, such as a sequence of beep tones, to aid an individual in properly orienting the satellite dish with respect to the satellite. A time interval between the beep tones is varied in dependence on the strength of the broadcast signal received at the low noise block. A circuit for providing the guidance signal is activated by a non-contact switch, such as a magnetic lead switch. A magnet is movably mounted on the surface of the low noise block for selectively activating and deactivating the guidance signal circuit.

Abstract: A mobile vehicular antenna for use in accessing stationary geosynchronous and/or geostable satellites. A multi-turn quadrifilar helix antenna is fed in phase rotation at its base and is provided with a pitch and/or diameter adjustment for the helix elements, causing beam scanning in the elevation plane while remaining relatively omni-directional in azimuth. The antenna diameter and helical pitch are optimized to reduce the frequency scanning effect. A technique is provided for aiming the antenna to compensate for any remaining frequency scanning effect.

Abstract: In an antenna apparatus provided at a mobile station for communication with a satellite, a transmitting antenna element for transmitting a signal having a certain transmitting frequency to the satellite is individually provided separate from a receiving antenna element for receiving a signal having a certain receiving frequency from the satellite, the transmitting frequency and the receiving frequency being different from each other.

Abstract: A proximity detection device for protection of personnel against exposure to hazardous radio frequency radiation. The device works by detecting the presence of people, either the operator or bystanders, who are in the system antenna's radio frequency radiation hazard zone. Upon detection, the device triggers a timer that delays the activation of alarm circuitry for a brief period of time. This time delay is instituted to minimize the triggering of nuisance alarms by a momentary intrusion in the hazard zone. If a presence is still detected after the delay time, pulsing visual and audible alarms are triggered to alert the system operator of the dangerous situation. The alarms remain activated for a timed period, allowing the operator to clear the hazard zone.

Abstract: A path finder/tracker system for assisting a person in finding the way back to a home base comprising a transmitter having a housing with electronic components therein, the electronic components including a emitter to emit a signal of a predetermined magnitude and frequency, the transmitter couplable to a power source with an on/off switch; and a receiver having a housing with electrical components including associated electrical components to receive the signal of the predetermined magnitude and frequency in the citizen band range tuned to that emitted by the transmitter, an antenna adapted to be retracted to a storage position within the receiver housing and extendable from the front edge thereof in a horizontal plane which is within the plane of the receiver, the receiver also including an array of lights across the front edge and adapted to sequentially light as a function of the strength of the signal received by the antenna whereby when the antenna is pointing directly at the transmitter, a predetermine

Abstract: An electronic article surveillance system is provided that comprises a core-wound drive coil which produces an AC magnetic interrogation field, and a detection coil provided on one side with at least one element of a screening material, which detection coil detects an AC magnetic response field generated by a magnetically active tag or marker which is subjected to the interrogation field when the tag or marker comes in proximity with the detection coil. The screening material may take the form of an open-ended electrically conductive box having an insulating gap along its length, or a laminate consisting of a plurality of metal foils interleaved with an electrically insulating material. The invention provides well-defined flux control for the detection coil which preventsinterference from unwanted external magnetic fields.

Abstract: A VHF radio (10) which includes an adjustable antenna (20) formed from a component (28) shaped like an open helical compression spring which engages and can be screwed into a metal supporting collar (40) for tuning the antenna (20). An elongated plastic or rubber cylindrical member (30) is connected to the metal collar and surrounds at least a portion of the helical member (28). An end cap (32) is provided for closing the other end of the cylindrical member (30).

Abstract: A diversity receiving apparatus having a plurality of antennas, antenna feeders each being associated with respective one of the antennas, and a single diversity receiving section to which the antennas are connected via the associated antenna feeders. A breakage detecting circuit is included in the apparatus for detecting the breakage of any one of the antenna feeders. The detecting circuit uses an antenna whose radiation element is connected to ground and, by applying a predetermined DC potential to the hot line of the antenna feeder via a resistor, constantly monitors the potential. On the breakage of the antenna feeder, the detecting circuit produces an alarm in response to the resultant change in the potential. The apparatus is capable of readily detecting that the diversity reception effect has been lost and the receiving ability has been degraded due to the breakage of the antenna feeder.

Abstract: A device for measuring bending movements of an antenna support mast, wherein the device being comprises: at least two sets of sensors separated by a determined distance d and fixed to the mast in the vicinity of the free end of the mast; and a processor for processing the signals by the sensors; the processor including means for memorizing the signals. The invention is particularly applicable to radio beam links.

Abstract: An apparatus for sensing the integrity of an antenna which is located within a wristband and which is coupled to a wrist worn communication device having a receiver, and an antenna sensing circuit which generates an antenna sensing signal. The antenna sensing circuit monitors the antenna sensing signal and derives an antenna integrity indication signal which indicates the integrity of the antenna. An indicating circuit is responsive to the antenna integrity indication signal and provides a sensible indication of the integrity of the antenna, such as a message indicating the antenna is open.

Abstract: The figure of an unfurled antenna comprising a radio-frequency reflective fabric (10) is mapped and controlled by a system comprising a plurality of light-emitting devices (14, 15) mounted at precisely specified locations on ribs (11), which support the fabric (10). Light from each of the light-emitting devices (14, 15) passes through a corresponding window assembly (16) on a hub (12), which support the ribs (11) and also houses a telescope of the Schmidt-Cassegrain type. A biconical reflector (27) mounted within the hub (12) directs rays of light from all the light-emitting devices (14, 15) to a primary mirror (21) of the telescope, from which the rays are reflected to a secondary mirror (22), which focuses the rays so as to form images on photodetector arrays (31) and (32). The images formed on the photodetector arrays (31) and (32) are swaths of light, which cross the photodetector arrays (31) and (32) at positions determined by the actual positions of the light-emitting devices (14, 15).

Abstract: A circuit for distinguishing the existence or non-existence of a signal at a satellite-broadcast receiver. The circuit includes an antenna adjusting part aimed toward the satellite after the satellite signal is tuned using a channel tuning stage driven by the output of a microcomputer. The level of the IF signal is detected by the IF signal AGC amplifier and the IF signal level detector. A video signal detecting stage detects the FM signal of the IF signal AGC amplifier output and the existence or nonexistence of the video signal is determined after audio/video signal processsing, and a channel displaying means, wherein the state of said video detecting part and the antenna position where video signal exists are displayed by on-sceen operations.