Abstract: A control unit is set up to operate a target device by receiving a first input for selecting from a plurality of protocols stored in the control unit a protocol that is appropriate for communicating with the target device. The control unit is then caused to transmit to the target device, using the selected protocol, a request for configuration information. In response to the receipt of the request, the target device returns to the control unit a function indicator and the control unit selects from a plurality of commands appropriate for the target device stored in the control unit a command corresponding to the function indicator. The selected command is mapped to a function key of the control unit such that activation of the function key results in communication of the selected command using the selected protocol to the target device to thereby control a function supported by the target device that is represented by the function indicator.

Abstract: A state-based remote control system for providing efficient and simple operation of a plurality of electronic devices as a coordinated system based upon an overall task. The state-based remote control system includes a housing, a keypad in communication with an electronic system contained within the housing, and a communication device in communication with the electronic system for communicating with external electronic devices. The electronic system monitors the buttons selected by a user to determine the state of all external electronic devices that are to be controlled. When the user selects a task (e.g. watch television), the electronic system automatically determines the actions required to achieve the desired task based upon the current state of the external electronic devices. After the task has been fulfilled, the electronic system updates the data to reflect the modified state of the external electronic devices.

Abstract: An electronic electricity meter which, in one embodiment, includes a modem board, or unit, coupled to the meter microcomputer and exchanges information between the meter and a central computer is described. Using signals supplied by the meter microcomputer and the central computer, the modem unit microcomputer can determine whether to exchange information between the meter and the central computer and the proper time at which the information should be exchanged. In an exemplary embodiment, the modem unit detects various conditions within the meter and responds by exchanging information with the central computer at a proper, or pre-defined, time. The modem unit has two different basic modes, or states, of operation. These states of operation are sometimes referred to as the call originate mode and the call answer mode. Call originate refers to the mode of the unit when a condition occurs in meter 10 and information is being transmitted to the central computer from the modem unit utilizing a telephone line.

Abstract: A novel system and method for achieving accurate readings of the rotational speed, number of revolutions and direction of rotation of a utility system. More specifically, a system and method for retrofitting existing utility meters with a lightweight tape, having contrasting sections of reflective and non-reflective material applied thereto, which is read by optical sensors as the lightweight tape passes by with the revolutions of the disk of the utility meter. Additionally, the system and method detects unauthorized use of the utility or tampering with the utility meter and its functions.

Abstract: A distance sensor device, in particular as a component of a parking aid or reversing aid for a motor vehicle, includes one or more distance sensors and a distance sensor control device for the purpose of activating the distance sensor or sensors via a respective signal line using an activation pulse that is quasi-digital and time-analog. At least one of the distance sensors has two different modes of operation. The modes of operation may be switched by varying the duration and/or amplitude of the activation from the distance sensor control device.

Abstract: A vehicle tracking system for a vehicle of a type including at least one vehicle sensor may include a vehicle tracking unit including a vehicle position determining device, a wireless communications device, and a controller connected to the wireless communications device and the vehicle position determining device. Furthermore, the controller may cooperate with the vehicle position determining device and the wireless communications device to send an alert message based upon the at least one vehicle sensor. The controller may also be switchable to an override mode to prevent sending of the alert message based upon receiving an alert override message. The vehicle tracking system may further include a monitoring station for receiving the alert message and for sending the alert override message.

Abstract: An apparatus and method is disclosed for providing a fast, low power consumption, detection of at least one depressed key in a resistive matrix keyboard. The common contact of each row of a resistive matrix is connected to a first input of each of a plurality of analog/digital comparators capable of switching between high and low voltage states. A common predetermined reference voltage is applied to a second input of each analog/digital comparator using a digital to analog converter. The output of a analog/digital comparator is in a first state if the voltage level applied to the first input is higher than the reference voltage, and in a second state if the voltage level applied to the first input is lower than the reference voltage. The reference voltage is varied to identify which analog/digital comparator has experienced a change of state.

Abstract: A system for compressed digital video bitstreams, in which an I-frame may precede a plurality of P-frames slices, wherein the system includes an encoder to encode the bits for each successive P-frame slice. The system also includes a decoder buffer, where the bits enter at a fixed rate and a decoder, which uses the extracted bits to decode each frame and display each frame. The delay is chosen at a fixed rate between 10 msec and 100 msec.

Abstract: In a method of lossless processing of an integer value signal in a prediction filter which includes a quantiser, a numerator of the prediction filter is implemented prior to the quantiser and a denominator of the prediction filter is implemented recursively around the quantiser to reduce the peak data rate of an output signal. In the lossless processor, at each sample instant, an input to the quantiser is jointly responsive to a first sample value of a signal input to the prediction filter, a second sample value of a signal input to the prediction filter at a previous sample instant, and an output value of the quantiser at a previous sample incident. In a preferred embodiment, the prediction filter includes noise shaping for affecting the output of the quantiser.

Abstract: A method, system, and apparatus for remotely calibrating data symbols received by a radio frequency identification (RFID) tag population are described. Tags are interrogated by a reader, which may be located in a network of readers. The reader transmits data symbols to the tags. Tags respond to the interrogations with symbols that each represent one or more bits of data. To calibrate the tags, the reader transmits a plurality of pulses of different lengths to the tag population. The tags receive the plurality of pulses. A characteristic of each pulse, such as a pulse length, is stored by the tags. The stored pulse lengths are used to define different data symbols that are subsequently received by the tags from the reader.

Abstract: An analog to digital method and apparatus corrects non-linearity error and gain error in a multiple stage pipeline analog to digital converter over a plurality of clock cycles. Preferably, continuous correction, during each of the plurality of clock cycles, of at least portion of non-linearity error introduced by a digital to analog conversion is performed in a first stage of the multiple stage pipeline analog to digital converter with use of an averaging over time of a first stage digital residue signal provided by the remainder stages of the multiple stage pipeline analog to digital converter. Such correction is used to provide a non-linearity corrected digital signal. Correction, during each of the plurality of clock cycles, of at least a portion of a gain error introduced by one or more amplifiers in the multiple stage pipeline analog to digital converter is provided by averaging the non-linearity corrected digital signal over time.

Abstract: An A/D converter calibration apparatus of the “skip-and-fill” type includes a set of operating condition parameter sensors (100) for detecting the current operating conditions, which are represented by parameters x1, . . . , xN. The measured parameter are forwarded to an operating conditions change detector (102), which calculates a change measure and determines whether this measure exceeds or falls below a predetermined change threshold. A calibration control signal CTRL_SKIP_RT is passed to a calibration control unit (104), which sets the background calibration skip rate to a high value if the measure exceeds the threshold an to a low value if it does not exceed the threshold.

Abstract: A method of amplitude control in a 1-bit digital system includes the step of scaling the stream of 1-bit data by a scaling factor corresponding to a selected output amplitude. The scaled data is modulated and the resulting modulated, scaled data is converted from digital to analog form.

Abstract: In the prior art, it has been difficult to provide a data generator and a data generating method which serve to implement an efficient transmitter, as well as a transmitter utilizing this data generator. The present invention provides a raw data generator that generates, from an inputted signal, an I signal and a Q signal which are orthogonal to each other and an amplitude component of a quadrature signal composed of the I and Q signals, a delta sigma modulator that delta-sigma-modulates the amplitude component, a first multiplier that outputs first data obtained by multiplexing normalized I data obtained by dividing the I signal by the amplitude component, by the delta-sigma-modulated signal, and a second multiplier that outputs second data obtained by multiplexing normalized Q data obtained by dividing the Q signal by the amplitude component, by the delta-sigma-modulated signal.

Abstract: An N-bit analog to digital converter includes a reference ladder connected to an imput voltage at one end, and to ground at another end, an array of differential amplifiers whose differential inputs are connected to taps from the reference ladder, wherein each amplifier has a first differential input connected to the same tap as a neighboring amplifier, and a second differential imput shifted one tap from the neighboring amplifier, and an encoder that converts outputs the array to an N-bit output.

Abstract: A technique for deskewing digitizer channels in an automatic test system includes applying a waveform of known frequency to the input of each digitizer channel. Each digitizer channel samples the waveform to produce a respective data record. A Discrete Fourier Transform (DFT), or a portion thereof, is then taken for each data record to determine, at minimum, the phase of the waveform. Phase differences across different digitizer channels are converted to time differences, which values are applied to subsequent digitizer measurements to correct for timing skew. Because a large number of samples in a digitizer's data record contribute to the computed phase of the waveform, the effects of timing jitter are substantially eliminated from skew measurements, without the need for repeating measurements and explicitly averaging results.

Abstract: An analog-to-digital converter system for sampling an input signal includes at least one offset channel. Each channel includes a differential amplifier with a signal input coupled to the input signal, an offset input for receiving an offset signal and an amplified difference output, an analog-to-digital converter having a signal input coupled to the amplified difference output and having a signal output, and an offset index signal source coupled to the differential amplifier offset input. The system further includes an offset controller having at least one output coupled to a corresponding at least one offset index signal source and at least one input coupled to a corresponding at least one analog-to-digital converter signal output. The system also includes a signal constructor having at least one input coupled to a corresponding at least one analog-to-digital converter signal output and operable to provide a relatively high resolution digital output signal.

Abstract: An Analog-to-Digital (A/D) converter includes signal paths that are responsive to an analog input signal, to generate a multi-bit digital signal. A respective signal path includes a comparator. A synchronizing circuit is responsive to a clock signal and outputs of the comparators, to generate a respective delayed clock signal that is applied to a respective comparator. A respective signal path also includes a respective decoder that is responsive to a respective comparator and to the clock signal.

Abstract: A voltage of an input analog signal (105 or 405) can be converted to a signal whose frequency is dependent upon the analog input signal (135 or 435). A frequency divider (115 or 415) can be configured to convert the frequency dependent signal to a frequency divided signal (140 or 440). A first frequency detector (420a) or time detector (120a) can be configured to determine the frequency of the frequency divided signal, thereby creating a first output signal (145a or 445a). A second frequency detector (420b) or time detector (120b) can be configured to determine the frequency of the frequency dependent or non-frequency divided signal, thereby creating a second output signal (145b or 445b). The first and second output signals can be post-processed to generate a digital output signal (130 or 430) that is representative of the input analog signal.

Abstract: A rail to rail dual slope analog to digital converter (ADC) is provided in the present invention. The circuit scheme has an input stage, an integrator stage, and a comparator stage, where an operational amplifier (OPAMP) can be comprised of each stage respectively. The positive input of the integrator OPAMP coupling to an analog ground, and switching the negative feedback loop of the input stage between an input voltage, a reference voltage, and a short circuit, controlling a plurality of switches among circuit connections results in different phases of the dual slope ADC. A finer resolution is thus obtained according to rail to rail input voltage range. Also, the integrator OPAMP can be eliminated from the circuit of the present invention in order to reduce pins, with connecting an end of the external integrator capacitor to ground.

Abstract: A method, apparatus, and system for providing accurate level shifting, residue multiplication, and sample-and-hold functions for ADCs, while eliminating capacitor mismatch as a source of ADC errors. An input signal is sampled onto a first capacitor, and the complemented input signal is sampled onto a second capacitor. The sampled input signal is provided to a first input terminal of a unity gain amplifier by controllably connecting the first capacitor between the amplifier output and the first input terminal. An inverted version of the sampled complemented input signal is level shifted and provided to the amplifier's second input terminal by controllably coupling the second capacitor between a selected level-shift voltage and the second input terminal. The sampled analog input signal is added to the inverted version of the sampled complemented analog input signal, while subtracting the selected level-shift voltage, to provide a residue signal available for use in subsequent conversion stages.

Abstract: There is provided a radar reflector apparatus that is mounted in a lifeboat or a small rescue boat or in a floating buoy used for salvage or search practice, or is used by itself independently, to serve as a radar wave reflector of a search radar. The radar reflector apparatus has a simple structure, and is folded when not in use, and when used, is unfolded automatically when dropped by a marine vessel or aircraft or the like.

Abstract: Methods and apparatus are disclosed for measuring position and motion of a “marker” antenna (14), disposed on a subject (12) at a physical location to be tracked. Relative distance of the marker antenna (14) from receiving antennas (18) is measured by phase differences of its microwave signals (40) at the receiving antennas (18) for at least two successive marker positions. Alternatively, actual distances (104, 106) are calculated by choosing a source position (102) and iterating the distances (104, 106) until the calculated phase differences match those measured. Four to six receiving antennas (18) are positioned at edges of a volume (16) where activity is conducted. Each received signal (40) is amplified and down-converted in a mixer (44). A single reference oscillator (46) feeds all the mixers (42) to preserve phase relationships of the received signals. Received signals (40) are digitized and presented to a multi-channel digital tuner (50).

Abstract: The present invention provides an apparatus, method, and system for determining a time of arrival (TOA) and time differences of arrival (TDOA) of a transmitted signal {S} receivable at different locations of known spatial coordinates. The system comprises a first transmitter 10 with a respective antenna feed point positioned at an a priori unknown location P and emitting a first signal {S}. The system includes furthermore a set of transceivers or transponder units 20, 30 comprising first receivers 22, 32 for receiving first signals {S} by means of respective antennas with feed points located at known locations Ln. Such system also comprises second transmitters 26, 36 emitting respective derived second signals {{tilde over (S)}n} after known and scheduled respective time intervals &dgr;n as measurable between the feed points of said respective first receiving antennas located at known locations Ln and respective second transmitting antenna located at locations L′n.

Abstract: A near object detection (NOD) system includes a plurality of sensors, each of the sensors for providing detection coverage in a predetermined coverage zone and each of the sensors including a transmit antenna for transmitting a first RF signal, a receive antenna for receiving a second RF signal and means for sharing information between each of the plurality of sensors in the NOD system.

Abstract: A mobile terminal having a function of measuring air sensitivity of global positioning system GPS and a method for measuring air sensitivity of GPS is disclosed. The mobile terminal includes: a memory for storing values of AGC PDM obtained by rotating a mobile terminal to a predetermined angle in a predetermined time period and obtaining values of AGC PDM in each predetermined angle; a computation unit for obtaining a mean value of values of AGC PDM; and a display unit for displaying the mean value.

Abstract: A method and a system for L1/L2 phase and magnitude determination in satellite navigation equipment is disclosed herein. The method generates separate W code estimates for the L1 signal and the L2 signal, the estimates being uncorrelated with the error in the inphase and the quadrature components of the corresponding signals. The W code is estimated using both the L1 signal as well as the L2 signal. The L1 and L2 baseband signals are obtained from the corresponding RF signals. The baseband signals are added and then filtered using a non-causal FIR LPF. This filter has the property that the output at a time instant is uncorrelated with the input at that time instant. In the preferred embodiment, a one-W-code-bit I&D filter is used instead of a FIR LPF. In an alternate embodiment, a single W code estimate is obtained for both the L1 and the L2 signal.

Abstract: An improved GPS signal receiver (and corresponding method of operation) includes a plurality of antenna elements each receiving a plurality of GPS signals (e.g., GPS LI signals or GPS L2 signals). A plurality of mixers (which correspond to the array of antenna elements) and a combining node convert the GPS signals received at the antenna elements in a frequency-division-multiplexed (FDM) manner over FDM frequency bands logically assigned to the antenna elements to produce a composite signal representing such GPS signals. An analog-to-digital converter converts an analog signal derived from the composite signal (which may be an intermediate frequency signal or a baseband signal) into a digital word stream. Demultiplexing logic extracts GPS signal components in the digital word stream. The GPS signal components correspond to the FDM frequency bands logically assigned to the antenna elements.

Abstract: A vehicle information system which includes an in-vehicle system 105 and a centralized server system 120. The in-vehicle system communicates with the server system using a wireless communication link 110, such as over a cellular telephone system. A position system, such as a set of GPS satellites 140, provides positioning signals that are used by the in-vehicle systems, and optionally by the centralized server system to increase the accuracy of position estimates. In one version of the system, an operator specifies a destination to an in-vehicle system which validates the destination. The in-vehicle system transmits specification of the destination to a server system 125 at the centralized server. The server system computes a route to the destination and transmits the computed route to the in-vehicle system. The in-vehicle system guides the operator along the route.

Abstract: A personal surveillance system configured to be worn by an individual includes a communication system configured to record communication files, a locating system configured to determine a location of the personal surveillance system, and a transmitter configured to send the communication files and the location of the personal surveillance system to a remote monitoring station. The locating system includes a satellite system interface configured to determine the location of the personal surveillance system and an alternate positioning system configured to determine the location of the personal surveillance system in at least one situation where the satellite system interface cannot determine the location of the personal surveillance system.

Abstract: The invention relates to a method for performing positioning, in which a spread spectrum signal modulated with a repetition code and transmitted by satellites, is received. The method comprises the steps of performing acquisition to the received, spread spectrum modulated signal, measuring the code phase of the received, spread spectrum modulated signal, and receiving the ephemeris parameters of satellites which are used in the positioning. In the method an optimizing phase is performed in order to minimize a cost function. The cost function includes a fraction operator having an argument that includes at least one residual error.

Abstract: An array antenna comprising a plurality of antenna elements, multipliers for multiplying coefficients with transmission or reception signal and a calculator for calculating the coefficients for each multiplier. The calculator generates the coefficients in a proposed method such that the beampattern of the array antenna has a flat top mainlobe with an adjustable beamwidth and a predetermined sidelobe ratio.

Abstract: In an electronic circuit for forming an antenna pattern, the antenna signals having the required phase shift are generated by means of two phase-locked loops which have a common reference signal. A control current, which is added at the output node of the charge pump 26 and/or 27, is used to control the phase shift of the antenna signals. This allows the implementation of the phase shift operation in the analog domain, which decreases the cost of a corresponding consumer device, such as a car-radio or a mobile communication system.

Abstract: This invention relates to a transmit/receive module for a high power Active Phased Array Antenna system operating in L-band based upon a combination of Hybrid Microwave Integrated Circuit (MIC) as well as Monolithic Microwave Integrated Circuit (MMIC) technology. The transmit/receive module includes a power monitoring means, transmitter protector means, and a receiver protector means. The module comprises a signal transmit chain incorporating power conditioner and a signal receive chain incorporating control electronics and bias- sequencer modulator. The transmit chain has switching means for switching the module to transmit mode which is connected to the transmit amplifier chain through a shared digital phase shifter. The amplified signals from the transmit amplifier chain are conveyed to a duplexer means.

Abstract: A phased array antenna system that is operative to simultaneously form multiple beams without requiring an undue amount of hardware. The system collects propagating energy with a number of antenna elements to form multiple beams, encodes the beams as the energy is collected, combines the encoded beams, and then decodes the combined signal to separate the beams. In this way, the beams can be formed with a single set of antenna hardware instead of requiring a multiplicity of antenna hardware, one for each beam. Frequency coding may be implemented by repeatedly applying a Doppler phase shift to each beam, and then using a Doppler filter to separate the beams. Alternatively, a code division multiplexing technique may be implemented by using a CDMA code generator to apply a code to each beam, and then using a CDMA filter to separate the beams.

Abstract: A steerable antenna array (10) includes a plurality of antenna elements (12a-12f) which receive broad band signals and narrow band interfering signals which together form antenna signals. The antenna signals are combined with weighting signals by combining functions (16a-16f) to form a combined signal, which is filtered by a filter function (30) to filter the narrow band signals. The filtered signals are sent to a weight processor (50) which also receives the antenna signals as an input. The processor (50) generates the weighting signals so that interference from the narrow band signals is reduced.

Abstract: A method of determining an azimuth and elevation of a radiation emission source using a single-axis direction finding system is provided. The method includes receiving a plurality of radiation signals at the single-axis direction finding system. The plurality of radiation signals are emitted from the radiation source, each of the plurality of radiation signals being received at one of a plurality of attitudes of the single-axis direction finding system. The method also includes measuring an angle of arrival of each of the plurality of radiation signals with respect to the single-axis direction finding system. Additionally, the method includes calculating an azimuth angle of each of the plurality of radiation signals with respect to the single-axis direction finding system using the respective measured angle of arrival. Further, the method includes calculating a respective vector corresponding to each of the azimuth angles at different elevation angles within a predetermined range.

Abstract: The invention relates to a method and arrangement for positioning one or more mobile stations, in which the location of the mobile stations is determined in the horizontal direction using at least two radio direction finding stations. Information on the location of each mobile station is maintained on a server. The mobile station measures at least one variable proportional to the location of the mobile station in the vertical direction and signals information on the measurement results to a control unit time-divisionally at the same frequency controlled by the control unit. In the control unit the location of each mobile station is determined in the vertical direction on the basis of the signalled data and the data on the location is conveyed to the server, where the three-dimensional location of the mobile stations is determined. The locations of at least some of the mobile stations are displayed graphically.

Abstract: The present invention is useful in connection with calibration of a wireless location system based on RF signals within a facility. Identification devices are provided at fixed locations which are selected within the facility. The RF environment is sampled at selected locations and data representing the sampled RF environment and the corresponding selected location is provided to a computer which maintains a database corrolating the RF environment data and the selected locations to be used with calibrating a location system.

Abstract: In a multi-resonance antenna, at an open end of a radiation electrode of a feeding element and an open end of a radiation electrode of a parasitic element capacitance loading electrodes and ground electrodes are arranged opposite to each other. In the opposing portions, electric-field deflectors are provided, thus reducing the electric-field coupling between the feeding element and the parasitic element.

Abstract: An antenna assembly for a telecommunication apparatus is disclosed. The antenna assembly has a conductive element defining a planar antenna and a flexible member arranged to carry the conductive element. A method of encapsulating a planar antenna within a flexible member is also disclosed.

Abstract: An antenna system for use in a communication system is provided. A first antenna is configured to receive a first signal having a first polarization. A second antenna is configured to receive a second signal having a second polarization and configured to receive a third signal having a third polarization. The second polarization is rotated from the first polarization. The third polarization is rotated from the second polarization.

Abstract: An antenna for automobiles including a coaxial coupler, which has an outer conductor, an inner conductor and a plastic supporting body that fixes the inner conductor inside the outer conductor. The antenna also includes a radiating element, which is connected to the inner conductor of the coupler in an electrically conductive manner. A circuit provided for antenna-matching is located on a circuit supporting plate, which is arranged between the radiating element and the inner conductor of the coupler and which extends toward the radiating element. The circuit is also connected to the inner conductor of the coupler as well as to the radiating element in an electrically conductive manner. A plastic sleeve which encapsulates the radiating element in which the outer conductor of the coupler is anchored.

Abstract: Antenna system composed of (N+1) virtually identical radiating structures with N greater than or equal to 1, said (N+1) structures being arranged parallel to each other and each radiating structure being connected to a power supply and impedance matching device. Use for frequency ranges between 1.5 to 30 MHz.

Abstract: A broad band slot style broadcast antenna utilizing coaxial hollow tubes, the inner tube discontinuous at its longitudinal center in order to provide two high power antennas at a single location. The outer tube has slots accompanying adjustable electromagnetic coupling structures.

Abstract: Paraboloidal antennas are common for very high frequencies (VHF) and into the cellular telephone systems and personal communication systems (PCS). Paraboloidal antennas are often used at the base station of either cellular telephone antennas, PCS antennas or both. To avoid possible channel drop out because a sharp focal point of the antenna is misaligned by improper installation or harsh weather conditions. For base stations for cellular telephone systems and/or systems, PCS, a generally paraboloidal antenna that has a less sharp focal point so there is a antenna lower gain, but less relative signal degradation because of weather or other misalignment of the antenna. In such cases, the lower gain, but higher immunity to drop-out more than justifies such arrangements.

Abstract: Power is supplied to antenna elements of a helical antenna section, which are arranged at an angular distance of 90° therebetween, with a phase difference of 90°. When a reception wavelength is &lgr;, the height of the helical antenna section is 0.6 &lgr; to 0.75 &lgr;, the number of turns, T, of each antenna element is about 1, and the pitch angle &agr; of each antenna element is 50° to 60°. A straight portion with a length corresponding to ¼ of the height of the antenna section is formed at a location corresponding to ½ to ¾ of the height of the antenna section, the height of the antenna section is about 0.3 &lgr; to 0.35 &lgr;, the number of turns, T, is about 1, and the pitch angle &agr; is about 22°.

Abstract: A circuit for supplying signals to a quadrifilar antenna that has an input port for receiving a first signal, a first transmission line connected at one end to the input port, and a first connection point. The first connection point is connected to another end of the first transmission line. The first connection point provides a path to a first antenna port. A second transmission line is connected at one end to the first connection point. A second connection point is connected to another end of the second transmission line. The second connection point provides a path to a second antenna port. A third transmission line is connected at one end to the second connection point. A third connection point is connected to another end of the third transmission line. The third connection point provides a path to a third antenna port. A fourth transmission line is connected at one end to the third connection point. A fourth connection point is connected to another end of the third transmission line.

Abstract: A circuit dividing and/or combining signals that has an input port for receiving a first signal, a first transmission line connected at one end to the input port, and a first connection point. The first connection point is connected to another end of the first transmission line. The first connection point provides a path to a first output port. A plurality of additional transmission lines, connection points and output ports is connected in sequence. Each transmission line is connected at one end to the (N−1)th connection point. A N connection point is connected to another end of the N transmission line. The N connection point provides a path to a N output port. The circuit provides equal amplitude at each of the anntena ports and further provides 90° phase progression between each pair of adjacent output ports.

Abstract: The present invention relates to radio engineering and is applicable to antenna feeder devices, mainly to compact antennas with enhanced broadbanding. An antenna comprises a spiral antenna made by conductors arranged in a single plane and formed into a bifilar helix. Two antenna elements are disposed in the same plane and coupled, opposite to each other, to the conductors at outer turns of the bifilar helix. The bifilar helix is a rectangular spiral made by line segments with right angles of the turns. Each of the antenna elements forms an isosceles trapezoid and is coupled to a termination point of a conductor at a vertex of the smaller base of the isosceles trapezoid. The bases of the isosceles trapezoids are parallel to the line segments of the bifilar helix.