摘要:
The invention relates to an antenna system for reception of channel signals from the UHF band by a receiver, comprising an electrically small antenna.The system also comprises, connected between the port connected to the antenna and that of the receiver, an active impedance matching device controlled by command signals depending on the quality of the signal received by the receiver to compensate for the impedance variations due to the environment associated with the antenna and to reject the frequencies of interfering channels adjacent to the reception channel without interfering with the active impedance matching of the antenna.
摘要:
An antenna system for reception of channel signals form the UHF band by a receiver, including an electrically small antenna and, connected between the port connected to the antenna and that of the receiver, an active impedance matching device controlled by command signals depending on the quality of the signal received by the receiver to compensate for the impedance variations due to the environment associated with the antenna and to reject the frequencies of interfering channels adjacent to the reception channel without interfering with the active impedance matching of the antenna.
摘要:
This invention concerns a repeater for radio frequency signals having a channel filter and an active filter connected to the channel filter output. The active filter covers the channels adjacent to the channel filter and includes an amplifier and; two bandpass filters in parallel connected as a negative feedback loop around the amplifier. The first bandpass filter covers the lower adjacent channels and the second bandpass filter covers the higher adjacent channels. The invention notably applies to the development of domestic repeaters for mobile terminals meeting the DVB-H digital television standard.
摘要:
A multi-antenna system feed device and a terminal including such a device is suggested.The device includes at least: a set of Wilkinson combiners, a branch of a combiner feeding an antenna, with the branches connected as inputs to a feed point; a set of switches connected between the antennas and the combiners with each switch switching a combiner branch to its corresponding antenna with the antenna being connected to the line when the switch is closed; A branch feeding an antenna, for instance, will be common to two consecutive combiners of the system. The suggested multi-antenna system feed device applies in particular to the extension of multi-antenna or sector antenna systems, used especially in devices with Multiple Inputs/Outputs of the MiMo type and more specifically to mesh network architectures.
摘要:
The invention relates to a switch with selective isolation and also to a switching device with selective isolation for multimedia terminals. The switch formed by 2 transistors (T1, T2) is feedback controlled by a feedback control signal V tune at a pre-defined frequency thus guaranteeing the selective isolation at this frequency. The switching device for switching the transmission/receiver channels of a multimedia terminal is formed by selective isolation switches that can be integrated using MMIC technology.
摘要:
The present invention relates to a diversity antennas system comprising at least two antennas of the dipole type each formed by a first and a second conductive arm, supplied differentially wherein the two antennas comprise a common arm called first arm forming at least one cover for an electronic card and each one a second arm mounted in rotation at one extremity of the first arm.
摘要:
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.
摘要:
The invention concerns a system of antennas on the same support. Each antenna is connected to a first port for the emission/reception in a first frequency band, and to a second port for the emission/reception in a second frequency band. The invention consists in a specific dimensioning of the support, such that the difference of the perimetric lengths separating the median points is a function of the half wavelength λ/2 modulo k λ, k positive integer, where λ is the wavelength corresponding to a working frequency fr.
摘要:
The present invention relates to a high rejection stop band filter and a diplexer using such filters.The stop band filter comprises on a substrate with a ground plane, a transmission line extending between an input and an output and comprises several resonators formed of “stubs” in printed open circuit embedded into the transmission line, the resonators being positioned in parallel together and interconnected in series in the same direction or head to tail.The filters are particularly useful in mobile devices operating in two concurrent frequency bands.
摘要:
The invention relates to a method for calibrating a terminal with a multi-sector antenna in a mesh broadcasting network that comprises at least one other terminal. The method includes: the selection of one sector of the terminal antenna to be calibrated, the reception by the selected sector, of identification signals transmitted by each of the other terminals present in the network, as well as the information on the received signal level; and the storage, for each sector, of different identification signals of the terminals present in the network, and of the information on received signal level, into the memory of the terminal to be calibrated.