摘要:
The present invention relates to a process and a device for the wireless transmission of a signal S.sub.1 between a transmitter and at least one receiver.According to the invention, at the sending end:a first carrier S.sub.2, of frequency F.sub.2, situated in the VHF (Very High Frequency) range, is frequency-modulated by the signal S.sub.1 to be transmitted, and thena second carrier S.sub.3 of frequency F.sub.3, situated in the SHF (Super High Frequency) frequency range, is amplitude-modulated by a modulating signal S.sub.2m. resulting from the frequency modulation of the carrier S.sub.2 so as to transmit an amplitude-modulated signal S.sub.3m to the receiver,and at the receiving end:amplitude demodulation of the signal S.sub.3m is performed so as to recover the signal S.sub.2m, and thenfrequency demodulation of the signal S.sub.2m is performed so as to recover the signal S.sub.1.
摘要:
Wireless transmission process and apparatus include a frequency diversity process for carrying out spectral spreading of a modulated SHF (Super High Frequency) carrier. The modulated SHF carrier transports information between a transmitter and at least one receiver. The frequency of the SHF carrier is varied continuously in a specified band so as to transmit to the receiver a signal having a spectrum containing a plurality of frequencies representing a plurality of uncorrelated signals each transporting the information to be transmitted.
摘要:
The invention relates to a wide-band omnidirectional antenna including at least a first conducting member and a second conducting member having a revolution symmetry about a common revolution axis and central openings, said members being arranged opposite each other, at least one member having a progressively flaring area, characterised in that it comprises a gap between the conducting members and a central coaxial excitation line so as to achieve a three-dimensional contactless transition between the coaxial excitation line and the conducting members and members for modifying the radiation pattern in the flaring area of the diode type for selectively radiating the gap depending on the on- or off-state of said diodes.
摘要:
The present invention relates to a multimedia mobile terminal capable of transmitting and receiving signals compliant with several standards in the UHF band. It comprises: a receiver receiving a first signal compliant with a first standard in a first frequency band, a first transmitter capable of transmitting a second signal compliant with a second standard in a second frequency band different from the first frequency band and partially intersecting the first frequency band, wherein, between the receiver and the antenna, a calibrated band-rejection filter comprising at least one variable element enabling the selection of a rejection frequency by the control voltage of said variable element. a filtering control element to store the control voltage values and the associated rejecting frequency values determined during a calibration procedure and to transmit according to the second frequency of the first transmitter the stored control voltage of said variable element of said band-rejection filter.
摘要:
The present invention relates to a multiple-port dual-band antenna system and the associated interface formed by DPDT or SPDT switches, that can be integrated on one and the same multi-layer structure.
摘要:
The invention relates to a wide-band omnidirectional antenna including at least a first conducting member and a second conducting member having a revolution symmetry about a common revolution axis and central openings, said members being arranged opposite each other, at least one member having a progressively flaring area, characterised in that it comprises a gap between the conducting members and a central coaxial excitation line so as to achieve a three-dimensional contactless transition between the coaxial excitation line and the conducting members and members for modifying the radiation pattern in the flaring area of the diode type for selectively radiating the gap depending on the on- or off-state of said diodes.
摘要:
The present invention relates to a compact wideband antenna of the dipole type comprising a first 1 and a second 2 conductive arm supplied differentially, one of the arms called first arm 1 forming at least one cover for an electronic card. Said type of antenna is connected to a portable electronic appliance such as a PC or similar device.
摘要:
The invention relates to a selective active low-pass filter and to a method for improving the selectivity of such a filter. The method consists in centring, in the centre of the network, the resonant element whose frequency is closest to the cut-off frequency of the filter and in inserting in series with this element a negative resistance of higher value than the parasitic resistance of the filter.
摘要:
The present invention relates to a multi-sector radiating device intended to receive and/or transmit electromagnetic signals, comprising at least, arranged on a plane substrate:a first set of antennas, with: a first antenna, a second antenna, a third antenna, arranged in the opposite manner to the first antenna, a fourth antenna, arranged in the opposite manner to the second antenna, the antennas being longitudinal radiation slot type antennas, said antennas each presenting a bisector,wherein the radiating device comprises a switching circuit capable of activating one or more of the antennas, and notably all the antennas of the first set of antennas, —and in that the bisectors of the opposed antennas on the substrate are not combined.
摘要:
The present invention relates to a method for integrating an identifier circuit in a data medium formed by at least one dielectric substrate covered by a conductive layer, the conductive layer comprising a part receiving data and a part without data. The method consists in etching in the part without data of the conductive layer, at least one resonating slot forming an antenna and coupling an integrated circuit to the slot.