Abstract: An advance notification system and method notifies passengers of the impending arrival of a transportation vehicle, for example, a school bus, at a particular vehicle stop. The system generally includes an on-board vehicle control unit (VCU) for each vehicle and a base station control unit (BSCU) for making telephone calls to passengers in order to inform the passengers when the vehicle is a certain predefined time period and/or distance away from the vehicle stop. Significantly, the telephone call to advise of the impending arrival preferably exhibits a distinctive ring so that the call recipient need not answer the telephone in order to receive the message. The VCU compares elapsed time and/or travelled distance to the programmed scheduled time and/or travelled distance to determine if the vehicle is on schedule. If the vehicle is behind or ahead of schedule, the VCU calls the BSCU, which then adjusts its calling schedule accordingly.

Abstract: The invention provides a navigation apparatus wherein necessary traffic information can be acquired without any key operation during running of an automobile. The navigation apparatus includes a positioning device for getting a present position, a map data retrieving device for retrieving map data from a map database, a map display unit for displaying a map, an input device for entering a desired condition to receive information, a memory for storing the entered condition, an access device for accessing to an external information source, and a decision device for deciding a status. The decision device receives information from the external information source through the access device, and the map display unit displays the received information in accordance with map data retrieved by the map data retrieving device if the status matches the condition stored in the memory.

Abstract: The present invention comprises a signal generator for sending an electrical signal from an expandable, flexible layer of material, the signal generator comprising an upper layer of flexible, resilient material and a lower layer of flexible, resilient material which between them define a cavity for enclosing an expandable material such as a cellular foam or gas, whereupon localized distortion of one of the layers of flexible material, effects a signal generation within the structure, which is transmissible through a proper circuit to an outside electrical device. A circuit may be arranged adjacent a plurality of said keys which senses when several of said keys are depressed in a skewed or sideways manner, so as to effect movement of a cursor or pointer on a monitor in communication with a processing unit and said keyboard.

Abstract: The invention relates to a method of encoding and decoding a data stream in which data type information combines with data packet length and identifier information to reduce the required length of the data stream while providing the added functionality of allowing for type checking at the receiving computer.

Abstract: According to the present invention, in the demodulating device, demodulating method and transmitting medium, a channel bit sequence of a variable length code having a minimum run d of 1 or more was decoded to a data sequence, and a code assigned to limit the minimum run d from repeating a predetermined number of times in the channel bit sequence of the variable length code was decoded to a data sequence. Design is therefore easier from the viewpoint of clock reproduction. When all the elements in the table contain a “1” representing an edge, data can be decoded more reliably. Further, when omissions are made in the codes in the table up to d bits from the code sequence lengths of the restriction lengths, data can be decoded more reliably. Thus, a clock is stably reproduced.

Abstract: A method for converting digital data which has been sampled at a first rate to a second rate. Audio data is stored on a compact disk at high frequency and it may be desirable to use this data on a codec which has a lower sampling rate. In the situation where the two sampling rates are not integer factors of one another a method has been developed to compare the ratios of the two sampling rates and using ratio to analyze each sample number of the bitword in the original data set to determine if sampling of that particular bitword is necessary.

Abstract: A method and apparatus to accelerate variable length decode is disclosed. The system includes a logic device to receive a bit stream of variable length encoded information. The logic device outputs a fixed length value corresponding to a variable length code received as part of the bit stream of the variable length encoded information. The system also includes a processor to receive the fixed length value. The processor to performs a write of a coefficient to a system memory device, the coefficient corresponding to the fixed length value received from the logic device.

Abstract: A decoding apparatus which efficiently stores information to determine an address value to read a decoded value from a decoded value memory. The apparatus performs decoding processing at a high speed, and further, reduces the memory capacity.

Abstract: A system and method for decoding telecommunication tracer information originating from any telecommunication network element and utilizing any commercial or proprietary telecommunication protocol. The system includes a storage repository for storing trace data that includes a plurality of individual events provided by a telecommunications network element that utilizes one or more telecommunications protocol. An encoder creates and stores a plurality of executable programs used to decode the trace data. A decoder engine receives trace data from the storage repository, determines the telecommunication protocol or protocols associated with the trace data, and invokes one or more executable programs stored in the catalog encoder subsystem to decode the trace data. A graphical user interface that receives an output from said decoder engine and displays the decoded results.

Abstract: A signal processing system includes a main digital-to-analog converter (DAC) for receiving a digital baseband signal and converting the digital signal into an analog signal. Also included in the system is a connection circuit for receiving the analog signal, and output terminal, and an analog filter coupled between the connection circuit and the output terminal for filtering the analog signal. The system includes a calibration circuit coupled between the connection circuit and the output terminal for setting an offset voltage level. The calibration circuit includes (a) an approximation circuit coupled to the output terminal and operable during a calibration mode to determine the offset voltage level and store the offset voltage level as a digital offset signal and (b) an offset DAC coupled between the connection circuit and the approximation circuit for converting the digital offset signal into the offset voltage level.

Abstract: In accordance with a specific embodiment of the present invention, a system is disclosed having an analog to digital converter and control module. The analog-to-digital converter includes an analog input, digital output, and control input. The control input of the analog-to-digital converter is connected to a pulse width modulated output of the control module which provides an offset pulse width modulated signal. During a first portion of the offset pulse width modulated signal a sampling capacitor is charged. During a second portion of the offset pulse width modulated signal an integration capacitor is charged.

Abstract: Encoders and decoders for applying composite codes to optical data signals include encoders and decoders for applying both subcodes and supercodes. The subcodes have a duration selected as less than or equal to an interchip duration or a chip duration of the supercodes. The encoders and decoders (“coders”) include fiber Bragg gratings configured to encode or decode a subcode, a supercode, or a composite code. By coding with a subcode coder and a supercode coder, a coder is reconfigurable by selecting different subcodes or supercodes. Communication systems and methods using composite codes are also described.

Abstract: A method for generating digital carrier signals for application as the carrier to a digital modulator includes providing a first repeating sequence of complex values occurring at a given sample rate and upsampling these values to a higher sample rate. A second repeating sequence of complex values is provided, wherein respective complex values in the second repeating sequence occur at the higher sample rate. The second sequence of complex values is employed to modulate the upsampled first sequence of complex values and thereby provide the complex carrier signal.

Abstract: A simplified algorithm for digital signal interpolation and a novel architecture to implement the algorithm in an integrated circuit (“IC”) with significant space constraints are presented. According to embodiments of the present invention, the interpolator is divided into two parts. The first part of the interpolator increases the sample rate by a factor of two and smoothes the signal using a half-band Infinite Impulse Response (“IIR”) filter. The second part of the interpolator increases the sample rate of the signal by a factor of thirty-two using a zero-order-hold (“ZOH”) circuit. In one embodiment, the half-band IIR filter is implemented using an all-pass lattice structure to minimize quantization effects. The lattice coefficients are chosen such that the structure can achieve all filter design requirements, yet is capable of being implemented with a small number of shifters and adders, and no multipliers.

Abstract: An analog-to-digital converter (200) has a first stage (207) to integrate and quantize the difference between a feedback signal (R) and an input signal (X) to a first intermediate signal (Y1) with a first resolution (M1), a second stage (208) to integrate and quantize the first intermediate signal (Y1) to a second intermediate signal (Y2) with a second, lower resolution (M2), a feedback stage (260) to convert the second intermediate signal (Y2) to the feedback signal (R), and a third stage (206, 270, 280, 285) to differentiate the first intermediate signal (Y1) to a third intermediate signal (W1), to delay the second intermediate signal (Y2) to a fourth intermediate signal (W2), and to add the third and fourth intermediate signals (W1, W2) to an output signal (Y) having a resolution that results from the sum of the first (M1) and second (M2) resolutions.

Abstract: A delta-sigma modulator for converting an analog input signal into a digital output signal comprises a modulator input (501) and a first analog to digital converter (504) coupled to the modulator input (501). The first analog to digital converter has a first analog input and a first digital output. The delta-sigma modulator further comprises an error quantization unit (505, 506, 507) coupled to the first digital output for determining the quantization error caused by the first analog to digital converter (504). Additionally it comprises first signal combining means (508, 708, 802) for combining the outputs of the first analog to digital converter and said error quantization unit to form the digital output signal.

Abstract: In a line driver that utilizes a digital-to-analog converter (DAC) to generate a current that is used to form an output voltage VOD, variations in the output voltage VOD are minimized by a calibration circuit that senses the output voltage VOD, compares the output voltage VOD to a reference voltage, and then increments or decrements the bias current fed into the DAC to match the output voltage VOD to the reference voltage.

Abstract: The present disclosure discloses an apparatus for generating a shaped waveform derived from a binary input signal. The apparatus receives a binary input signal and a sample clock signal. The sample clock signal changes the state of an up/down counter. The binary input signal controls the counting direction of the counter. The counter addresses a lookup table containing stored values. Also disclosed is the apparatus in which the lookup table output is converted to an analog signal by a digital-to-analog converter. The lookup table can be programmed such that the circuit output is equivalent to a filtered version of the binary input signal. The apparatus may optionally be enabled or disabled, such that the apparatus output assumes a predetermined state when disabled.

Abstract: A method and a system for acquiring signal behavior parameters (LSBPs) of a band-limited (BL) signa, for representing and processing the signal, wherein the LSBPs encode the signal's local behavior in between Nyquist rate points. Preferably, a section of a BL signal within a sampling window is represented as a truncated series of order n at a sampling moment within the sampling window. The truncated series having n+1 LSBPs as its coefficients, encoding the signal's local behavior between Nyquist rate points. Compared to the conventional approach that encodes a signal's behavior by signal samples taken at Nyquist rate points, the invention encodes more signal behavior. Discrete signal samples are obtained from the signal. The LSBPs are solved numerically such that the interpolated values of the truncated series provide the least-square fit with the discrete signal samples.

Abstract: An analog-to-digital converter amplifier that is configurable with one gain for driving one terminal of a sampling capacitor while the other terminal is sampled to an analog input signal during one time period, and configurable with a different gain for comparing the analog sample with a DAC-generated reference voltage during a second time period.

Abstract: A current mode pipelined analogue to digital converter (ADC) has a plurality of serially connected conversion stages. Each conversion stage has an input (40) for receiving a sampled and held current which is connected via a switch (S41) to a first current memory (M42) and via a switch (S40) to a second current memory (M41). The output of the second current memory (M41) is fed via a switch (S44) to one input of a summing junction (46). The output of the first current memory (M42) is fed via a switch (S42) to the input of a comparator (L44) whose output is clocked into a latch (L44) whose Q output is connected to an output (45) as the digital result of the conversion. The Q output of the latch (L44) is also connected to a digital to analogue converter (46) whose analogue output is fed to a second input of the summing junction 46 via a switch (S43) to form the analogue residue signal for application via output (47) to the next conversion stage in the pipeline.

Abstract: The present invention relates to multi-function, multi-channel digital receiver architecture for performing three distinct receiver functions including simultaneous intrapulse analysis, direction finding and LPI signal detection; for determining parameters of incoming signals, comprising a plurality of receiver channels, each channel including a respective antenna for receiving the signal; a down-converter for converting the signal to an intermediate frequency (IF) signal; and an analog-to-digital converter operatively coupled to receive the IF signal and to provide a digital signal at a sampling rate, the digital signal being indicative of the amplitude and phase of the received signal in the channel, and a digital processor operatively coupled to receiving the digital signals from each of the plurality of channels for determining the amplitude and phase intrapulse profiles; by combining the amplitude and phase intrapulse profiles from all of the plurality of channels to provide both intrapulse and conventio

Abstract: A coded phase modulation communications system which relates to communications systems in which undesired detectability of the radiated signal is materially reduced, and wherein the vulnerability of the system to interfering signals, such as, intentional jamming signals, is substantially reduced. In the system, a radio frequency communications signal is phase modulated by a random or random appearing, but repeatable pattern of noise signal. The received signal is modulated by an identical noise signal, which when synchronized with the original noise modulation results in erasing the noise, and thereby recreating the original, continuous, communications signal. The noise source of the system is a pseudo noise generator that may be readily synchronized with an identical noise source or sources. The pseudo noise generator provides an apparently orderless noise-like sequence that may be exactly reproduced at the same or at a remote location or locations.

Abstract: A method and apparatus for transmitting a directional reply signals in response to Air Traffic Control Radar Beacon System and Mode Select signals interrogation signals. Two directional antennas independently acquire an interrogation signal and are connected by means of a configurable switch to a transponder. The antennas may include multiple directional antenna elements.

Abstract: The millimeter-wave zoom antenna for guiding a beamrider hypervelocity missile uses varying range information derived from the flight of the missile toward the target as control signals for the beam control computer to perform electronically the zooming and the nutation of the millimeter wave guidance beam that emits from a phased array antenna so as to maintain a constant energy density at the missile receiver regardless of the actual distance of the missile from the launch platform at any given time.

Abstract: Dual path detection processing in which a low SNR signal processor detects signals over a limited range of low acceleration values and a high SNR signal processor detects signals over a wider range of acceleration values. The low SNR signal processor uses acceleration bins formed from a noncoherent FFT array to detect low SNR signals of far away objects which tend to have lower angular acceleration. Because close proximity target objects tend to have higher SNR return signals, it is not necessary to rely on acceleration bins formed from an FFT array for signal detection. Close proximity targets with high SNR can often be detected in individual coherently integrated FFT templates, despite the likelihood of large acceleration uncertainty from higher angular acceleration rates.

Abstract: A method and apparatus is disclosed for measurement processing of Satellite Positioning System (SPS) signals. A plurality of SPS signals from a corresponding plurality of SPS satellites are received in an SPS receiver. The signal environment corresponding to the location in which the SPS receiver is located is characterized to produce signal environment data. In one exemplary embodiment, an information source, such as a cellular network based database, is searched to retrieve the signal environment data given an approximate location of the GPS receiver. This approximate location may be specified by a location of a cell site which is in cellular radio communication with a cellular communication device which is co-located with the GPS receiver. One or more parameters related to signal characteristics of the satellite signals are defined. Threshold values for the parameters are determined using the signal environment data.

Abstract: A cellular network protocol which minimizes the required data flow between the cellular infrastructure and each mobile handset supporting a GPS based positioning capability is taught. Four specific innovations are introduced which together minimize the number of bits required to be transferred to each handset: a method for reducing or removing the requirement for GPS ephemeris updates to each mobile; a method for compression of the differential correction broadcast message; a method for controlling the rate at which the network updates each handset's ephemeris based on an ephemeris age limit; and, finally, a method which each mobile can use to determine when an ephemeris update is needed, based on an accuracy prediction and a threshold which is unique to each mobile.

Abstract: Disclosed is a method for inter-antenna baseline determination that uses an antenna configuration comprising a pair of relatively closely spaced antennas and other pairs of distant antennas. The closely spaced pair provides a short baseline having an integer ambiguity that may be searched exhaustively to identify the correct set of integers. This baseline is then used as a priori information to aid the determination of longer baselines that, once determined, may be used for accurate run time attitude determination.

Abstract: Disclosed are methods for increasing the fail-safety characteristics of tracking systems for navigation receivers which receive signals from many satellites. In an exemplary embodiment of the present invention, an individual PLL circuit is used to track the phase of each satellite's carrier signal, and a vector common tracking loop is used to track the disturbances of the carrier phases which are caused by one or more common sources, such as the movement of the receiver's antenna(s) and/or the phase fluctuation of the receiver's main reference oscillator. The vector common tracking loop uses phase information from all of the satellites being tracked, and for this reason can be made more wide-band than each of the individual PLL circuits. The wider bandwidth of the vector common tracking loop provides higher dynamic properties and more safe tracking when faint and weakening satellite signals are present.

Abstract: A method and system for determining a position of an orbiting transceiver in a communications network includes at least a first and second transceiver at a first and second known location, respectively, on Earth. The first and second transceivers are adapted to transmit and receive communications signals to and from the orbiting transceiver. A processor coupled to one of the first and second transceivers determines a first and second range measurement between each of the first and second transceivers and the orbiting transceiver, respectively, as well as corresponding first and second range rates representative of a time rate of change of the first and second range measurements.

Abstract: This disclosure sets out a GPS receiver cooperative with a CPU having a memory. The memory enables inputting of data defining an electronic fence, i.e., a set of locations or a region where the vehicle is permitted to be operated. The electronic fence may be cooperative with a set of permitted driving instructions defining a delivery pathway for a set of stops, there being one or more delivery paths, which in conjunction with a clock, enables the vehicle to make delivery trips of a different nature at different times. Audio, visual and ignition control alarms are included to limit or stop vehicle operation outside the permitted locations.

Abstract: An optical control device for an electronic scanning antenna having at least two controlled radiating elements, and including means for providing first and second mixed light beams, the first light beam polarized according to a first direction and having a first wavelength (&lgr;1), and the second light beam, polarized according to a second direction and having a second wavelength (&lgr;2); at least two optical delay circuits each receiving the first and second mixed light beams and configured to induce complementary delays compared to a determined time value on the first and second beams; chromatic separators each situated at the output of a corresponding one of the delay circuits and configured to separate the light having the first wavelength (&lgr;1) from the light having the second wavelength (&lgr;2); first photodetectors each coupling a corresponding radiating element to a corresponding chromatic separator; second photodetectors each coupling a corresponding chromatic separator to a corresponding first

Abstract: A phased array antenna including at least one configurable phase shifter. The configurable phase shifter includes a U-shaped primary waveguide section and multiple switchable waveguide U-shaped sections disposed within the primary section. The switchable waveguide sections include a plunger in the U-shaped waveguide section and one or more solenoids attached to the plunger, driving the plunger in and out such that the switches can be actuated in less than 100 milliseconds. The plunger and the switchable waveguide section are shaped such that the waveguide height is constant in the U-shaped waveguide section when the switch is closed and constant in the primary waveguide section when the switch is open, thereby minimizing return loss. The U-shaped primary waveguide section includes an input port and an output port at opposite sides. A radiating slot is located at the bottom face of the U-shaped primary waveguide section.

Abstract: The present invention uses feedback 300 from RF carrier frequency measurements 301 to disassociate the emitter angle-of-arrival component 313 in the ambiguous phase measurement 312 from the initially unknown phase measurement integer ambiguities 314; to then process 302 resolve the ambiguities; and finally to process 303 to obtain the correct emitter AOA. The present invention does this by converting the actual interferometer baselines 315 on which the unassociated pulse 308 phase measurements 304 were made at different emitter frequencies to a baseline set 305 for a single-frequency equivalent interferometer array. This conceptual array has the following property: the phase measurement 306 that would be made on it at the fixed frequency for a signal at the same direction-of-arrival 307 are identical to the actual phase measurements made on the physical array. Because of this equivalency the conceptual array is called the E(equivalent)-array.

Abstract: A direction-finding method for determining an incident angle of a high-frequency electromagnetic signal in a system including at least two receiving antennas spaced apart by a known distance. the antenna output signals of the at least two receiving antennas are converted, together (in accordance with a multiplexing procedure) or individually, into the frequency domain through a Fourier transformation, followed by a conversion into an IF range and an A/D conversion. In this range, the phase difference between the output signals is determined and the signal frequency of the incident wave is determined through a phase-sequence analysis. The incident angle of the incident wave is determined from the phase difference and the signal frequency.

Abstract: This invention relates to panes, notably laminated panes, composed of at least one sheet of rigid material, and permanently containing a surface antenna composed of at least one microstrip separated from an earth plane by a dielectric. These panes, having such an antenna, are used for the reception and transmission of frequencies higher than 1 GHz and preferably for the frequency bands 5795-5815 MHz, 63-64 GHz and 74-77 GHz.

Abstract: A dielectric antenna including a filter, comprising: a dielectric substrate; an antenna portion, comprising a radiation electrode having one short-circuited end and one open end and provided on or within the dielectric substrate; a filter portion comprising; at least one resonance electrode provided on or within the dielectric substrate, and a external coupling electrode in association with the resonance electrode; and the radiation electrode and the resonance electrode being coupled to each other.

Abstract: A microstrip antenna includes a ground plane element and a radiating element. An elongated trough is formed generally in the middle of the radiating element so as to divide the radiating element into two generally equally-sized portions, and in a manner to extend outward from a bottom surface of the radiating element. The trough includes a first side edge, a second side edge, and a bottom surface. A first radiating portion extends from the first side edge, and a second radiating portion extends from the second side edge. The trough provides an elongated microstrip-size element at the bottom surface of the trough. A relatively thin dielectric layer is provided between the bottom surface of the trough and a corresponding portion of the ground plane element, thereby providing that a microstrip transmission line is formed by the bottom surface of the trough, the thin dielectric layer, and the corresponding portion of the ground plane element.

Abstract: A diagnostic device having a diversity processor for individually testing the electrical condition of the connections of individual antennas of a multi-antenna system in a motor vehicle. This device can be coupled to the interfaces of an antenna amplifier containing a diversity system, and such a test can be carried out without any intervention in the circuitry of the receiving installation. The diagnostic device contains a test unit and a control unit. The test unit is designed for generating a test signal that is received by an antenna of the multi-antenna system by a transmitting antenna. The diversity system is acted upon by a control unit having a control signal consisting of an IF-signal and a dc voltage signal. The control signal generated by the control unit by an interference simulator integrated in the control unit is disturbed only when the diversity system is prompted to switch to the next antenna.

Abstract: An adjustable antenna for receiving broadband signals. The antenna includes a first elongated antenna rod that is held next to a second elongated antenna rod in a parallel orientation to the first elongated antenna rod. The antenna rods are supported by a clamping or supporting device that allows the two rods to be slid relative to one another so that the antenna may be tuned to a particular frequency. Electrical contacts to the rods are also provided to allow transmission of the collected signal to a desired device.

Abstract: In an antenna structure including multiple antennas, a first antenna can include a conductive patch and a second antenna can be adjacent the conductive patch. More particularly, the second antenna can define a central axis wherein the central axis is orthogonal with respect to the first antenna and wherein the central axis intersects a central portion of the conductive patch. Alternately or in addition, a first antenna can include a conductive patch with an opening through the conductive patch, and a second antenna can be adjacent the conductive patch wherein a feedline for the second antenna extends through the opening through the conductive patch.

Abstract: In a waveguide lens for primarily circularly or linearly polarized electromagnetic radiation there is one or several rotationally symmetrical rings, arranged concentrically about a lens axis, for focusing of the incoming part of an electric magnetic wave, which has a polarization parallel to the rings, to a focus. For a still more efficient reception one or more plates arranged radially are designed so that the radial component of the electromagnetic wave is focused to the same focus. Alternatively there is instead of rings one or more spiral arms extending from the lens axis. The lens eliminates the problem of existing lens types that they only receive waves having a predetermined polarization which must be adapted to the orientation of the lens plates and the phase shifting elements. It makes for instance the reception of satellite signals more difficult, where the satellite signal is polarized in relation to the earth axis and the latitude where the satellite is located.

Abstract: The addition of semiconductor spacers into the spaces between the metal strips of a metal grid permits electron-hole plasmas to be introduced there controllably. Thus, the grid can be made to transmit or reflect an incident wave with a polarization perpendicular to the strips depending on whether or not the spacers are filled with minority carriers. The presence of carriers may be controlled electrically, optically and by field effect means which permit the basic metal strip/semiconductor structure (MGSS) to operate as a reconfigurable hologram, a reflector, a phase shifter, a switch, and a beam-steering antenna.

Abstract: A method and a device are disclosed for the generation of a surface, the reflection phase gradient or transmission phase gradient of which will be varied by means of a controllable static electric field. The present solution takes into account, instead of mainly the transmissive properties, also the reflection properties of an arrangement comprising a ferroelectric material. Such a reflecting surface may contribute to an entire antenna aperture, a portion of an antenna aperture or an element in a conventional array aperture. In a general case N lobes and M nulls are to be controlled at the same time. In such case the surface will preferably be designed as a curved surface, for instance a rotation symmetric parabola, while in other cases the reflector element may be designed just as a plane mirror. An antenna comprising such a reflector element of ferroelectric material can also form a polarization twisting Cassegrain antenna with a flat or curved main reflector element.

Abstract: It is an object of the present invention to provide a wide range azimuth (AZ) driving system for an antenna which has a simple structure and enables costs to be lowered and a producing time to be short. A first worm reducer which is connected to a worm shaft of a motor and a second worm reducer which is intermittently driven by the worm shaft and a clutch are provided, and gears of the two worm reducers engage with a large gear which is arranged to an antenna yoke. Further, one motor can arbitrarily control backlash and both wide range driving at a high speed and tracking driving with high precision are simultaneously possible by properly controlling the clutch and the motor.

Abstract: A multi-layered slotted antenna with reduced susceptance and increased conductance with a minimal effect on antenna radiation in the azimuth. Separate conductors are connected across the individual slots to reduce the slot susceptance with a minimal effect on slot radiation.

Abstract: An array antenna includes a patch arrayed on a metal backing plate and a plurality of inputs connected to the patch so as to radiate and receive an electromagnetic wave via the patch. The array antenna includes a transmitting/receiving circuit for feeding or receiving signals at a specific frequency to or from the array antenna. A waveguide divided into sections is provided to feed the electromagnetic wave to the radiating antenna. Each waveguide section produces a specific phase difference along the array antenna which accumulates and causes the electromagnetic wave to focus at a particular angle. Each waveguide section therefore produces a wave focused at a different angle, allowing the antenna to generate a plurality of focused waves.

Abstract: A feedhorn of the invention comprises: at least first and second waveguides in positions so as to face each other over a center line, each having an axis parallel to the center line; and first and second horns on extension lines of the axes. The outer ends of the first and second horns have aperture end faces, respectively. Each of the aperture end faces of the first and second horns is tilted toward the center line by a predetermined angle so that the first and second horns are perpendicular to the travel directions of radio waves transmitted from at least two broadcasting satellites orbiting around the earth and reflected by an antenna on the ground.

Abstract: Dual-polarized dipole radiator which comprises a plurality of individual dipoles which are preferably arranged upstream of a reflector (33) and form a dipole square structurally in top view, each dipole (111-114) being fed by means of a symmetrical line (115-118), characterized by the following further features: the dual-polarized dipole radiator radiates electrically in a polarization at an angle of +45° or −45° to the structurally prescribed alignment of the dipoles (111-114); the end of the symmetrical or substantially or approximately symmetrical lines leading to the respective dipole halves (111a to 114b) are connected up in such a way that the corresponding line halves (115a to 118b) of the adjacent, mutually perpendicular dipole halves (114b and 111a; 111b and 112a; 112b and 113a; 113b and 114a) are always electrically connected; and the electric feeding of the respectively diametrically opposite dipole halves is performed in a decoupled fashion for a first polarization and a seco