Abstract: The invention reduces the size of waveguide circuits. The invention proposes to change the cross section of a waveguide in a curved part. Thus, a curved element according to the invention makes it possible at the same time to make a change in waveguide cross action.

Abstract: The system includes a remote controlled apparatus furnished with a display device or adapted to be linked to such a device; a remote control device comprising a microphone; voice recognition circuit adapted to receive the signal emanating from the microphone and to generate a signal for controlling a functional feature of the apparatus corresponding to the word or group of words picked up by the microphone. The system comprises means for displaying on the said screen a list of the words or groups of words corresponding to the functional features of the apparatus which can be accessed by voice control in a window of the screen so as to enable the user to ascertain the key words which he has to utter in order to trigger these functional features.

Abstract: The invention provides a dielectric resonator oscillator DR, especially for transmission devices whose oscillating frequency may take several values. The oscillator uses two interfering conductors 30 and 31 switched so that they may or may not form a metal plane close to the dielectric resonator DR in order to vary the frequency of the oscillator while using a single resonator. The interfering conductors 30 and 31 are located in the cavity CAV close to the resonator DR and the switching means may or may not establish an electrical contact between the said interfering conductors 30 and 31.

Abstract: Compact, planar antenna made on a substrate comprising an annular slot which is dimensioned to operate at a given frequency and which is placed in a short-circuit plane of a line via which the antenna slot is fed. A second slot feed line is symmetrically disposed with respect to the first line in the line short-circuit plane common to them. Each of the lines, furnished with a port, is connected to a switching facility so as to allow the feeding of the antenna through one or the other of the two ports.

Abstract: A tuner for receiving a video broadcast signal comprises commendable circuits (6, 7, 8, 17) to select a tuned frequency, the tuner comprising a bus interface (21) receiving data bytes and among those data bytes, bytes representing a divider ratio N, and address bytes. Bytes received by the bus interface (21) are processed through a N divider comparator (23) comparing the value of divider ratio N received from the bus interface (21) to values stored in a register (24), the comparator (23) outputting address bytes and data bytes to be sent to the commendable circuit (6, 7, 8, 17) of the tuner to select a band and a tuned frequency. The tuner may be implemented on a chassis of a receiver without modification of an existing software included with a microprocessor of the chassis. The values stored in the register (24) are customized values of the tuner.

Abstract: The present invention relates to a device for receiving/transmitting electromagnetic waves with omnidirectional radiation of the type comprising: a first set (100a, 100b, 100c, 100d) of means for receiving/transmitting waves with longitudinal radiation of the printed antenna type, the said means being arranged in order to receive a wide azimuthal sector and at least a second means (104) for receiving/transmitting waves with transverse radiation of the printed antenna type, the second means having radiation complementary to the radiation of the first means, and means (103) capable of connecting in emission the said first and second wave receiving/transmitting means. The invention is especially applicable to domestic networks.

Abstract: For optimum videotex data coding, for error-free functioning of so-called descramblers and—not least—for the impression of improved detail resolution on the screen of a television set of displayed pictures, it is known to process the video frequency response by influencing the higher frequency components in the video signal spectrum. According to the invention, adaptation to a video frequency response sought is in each case carried out automatically by means of corresponding shifting of the vision carrier relative to the IF total transmission curve. The respective adaptation for the relevant television channel of the set is effected, in principle, by the addition of a corresponding correction value to the corresponding channel tuning voltage of the tuner.

Abstract: A device for sending and receiving electromagnetic waves comprises an antenna with a waveguide, a sending card and a receiving card. The sending card and the receiving card each extend essentially from the waveguide, and therefore from the antenna axis, in a plane perpendicular to this axis and between them form an angle greater than 90°.

Abstract: Apparatus and a concommitant method for generating an approximation of a logarithmically attenuated value of a digital signal in predefined increments. Specifically, the apparatus comprises a shift register, a latch and an adder. The shift register selectively shifts the digital signal a first number of bits to the right to produce a first shifted signal and then a second number of bits to the right to produce a second shifted signal. The latch is connected to the shift register and latches the first shifted digital signal while the digital signal is being shifted to form the second shifted signal. The adder is connected to the shift register and the latch and adds the first shifted signal to the second shifted signal to produce the attenuated value of the input digital signal.

Abstract: The present invention concerns a digital signal tuning apparatus which includes an offset frequency correction system. In the offset frequency correction system, searching for an offset signal starts from an end point of a band of frequencies in which the offset signal may be found.

Abstract: Waveguide filters for filters operating at millimeter wavelengths which require high accuracy. The filter includes a plurality of discs held in the cylinder of a support. Each disc has a recess defining cavity size. The various parts forming the filter are simplified thereby making it possible to reduce production costs while providing good accuracy.

Abstract: The present invention relates to a device for transmitting and/or receiving electromagnetic waves comprising at least one radiating element for radiating a circular polarization of given sense, characterized in that it comprises at least one means dimensioned and positioned with respect to the radiating element in such a way as to radiate, at the frequency of the radiating element, a circular polarization of opposite sense to that of the radiating element so as to compensate for the cross component of the radiating element. The invention applies more particularly to printed antennas operating under circular polarization.

Abstract: The invention relates to a telecommunications device with an electronic scanning array shaped according to a first surface with rotational symmetry, comprising: a first array of first radiating sources arranged over the said first surface in order to operate about a first central frequency. According to the invention, the device comprises, in addition: a second array of second radiating sources arranged over a second surface with rotational symmetry adjacent to the said first surface in order to operate about a second central frequency, the first and second sources being placed such that a first source and a second source do not face a second source and a first source respectively, along a section normal to the first and second surfaces pointing to the first source and the second source respectively.

Abstract: A tuner includes a tunable filter for selecting a desired RF signal in response to a tuning control signal and a tunable image trap for rejecting the undesired image signal corresponding to the desired RF signal responsive to the tuning control signal coupled in cascade between an RF amplifier and a mixer. The tunable trap also serves as an impedance transformation element between the tunable filter and said mixer. The arrangement is particularly useful in a tuner in which the frequency range of the local oscillator signal is below the frequency range of the received RF signals.

Abstract: The invention relates to a focusing device comprising a Luneberg lens comprising a homogeneous volume of dielectric. It is characterized in that the dielectric comprises a granular agglomerate defined by a homogeneous granule size distribution of thermoplastic granules, at least one plurality of these granules being welded together by granule boundaries in order to keep said volume consolidated. Particular application to lenses for the tracking of nongeostationary satellites, of at least one geostationary satellite, or for use in an MMDS system.

Abstract: The high frequency oscillator comprises a reference oscillator, a phase-locked loop circuit with a phase frequency detector, a charge pump, a ring oscillator and a divider, the reference oscillator being coupled to the phase frequency detector for frequency control. The ring oscillator is a symmetrical delay cell oscillator containing two amplifiers with a dual output stage for providing I/Q output signal generation. The reference oscillator works in the range of 1.25-1.5 GHz and is a Colpitts type digital controlled frequency synthesizer with an external tank circuit for providing a low phase noise, and the dividing factor of the divider is four for providing a tuned output range of 5 to 6 GHz. The phase-locked loop circuit is integrated together with the reference oscillator into an integrated circuit, using advantageously a BICMOS Silicon/Germanium process, which is well suited for RF applications.

Abstract: According to the invention a digital signal path includes a first filter and an analog signal path includes a second filter. For analog reception both filters are connected in cascade, the first filter aiding the second filter in achieving a desired selectivity. Additional selection devices are obviated. Preferably the filters are surface acoustic wave filters.

Abstract: The present invention relates to a T-circuit produced using microstrip technology with two branches (2, 3) of identical length L2 comprising a phase-shifting element (6) producing a given phase shift &PHgr; by extending one of the branches, the T-circuit operating in broadband, the circuit comprises at least one elbow (4) extending the branch (3) without the phase-shifting element and the length L2 is equal to a multiple of &lgr;g/2 where &lgr;g is the guided wavelength.

Abstract: The present invention relates to a source antenna for transmitting/receiving electromagnetic waves comprising means for transmitting electromagnetic waves with longitudinal radiation operating in a first frequency band and means for receiving electromagnetic waves, characterized in that the means for receiving electromagnetic waves consist of a first array of n radiating elements operating in a second frequency band and a second array of n′ radiating elements operating in a third frequency band, the first and second arrays and the longitudinal-radiation means having a substantially common phase centre and the radiating elements of the first and second arrays being arranged around the longitudinal-radiation means.

Abstract: An antenna tuning apparatus for VHF/UHF antenna comprises an automatic gain control (AGC) arrangement, including an amplifier, the gain of which is controlled by the AGC arrangement, and a plurality of impedance matching networks which are coupled between an antenna input of the tuning apparatus and the AGC-controlled amplifier. A remote controller is provided to select both channels of a television apparatus, for which the tuning apparatus provides VHF/UHF signals, and proper matching networks suitable for respective ones of selected channels simultaneously. Each one of the plurality of matching networks exclusively provides the AGC arrangement with a respective group of RF signals which includes a plurality of receivable broadcast channels. The gain of the amplifier is controlled in response to the level of the group of RF signals.