Abstract: The present invention relates to an active band stop filter comprising a filter input and a filter output which are linked by a transmission line LT, a resonator RE coupled to the transmission line and connectable to a load impedance. Between the resonator and the load impedance there is mounted a means of activation of the filtering function in a chosen operating band. The filter is useable in multistandard terminals.

Abstract: Based on an active low-pass filter structure comprising a main conductor line between an input port and an output port, consisting of an input conductor section, an output conductor section, and an inductance network in series between the input and output sections, the inductance network being coupled to the LC resonators, an LC resonator connected to each junction point between two network inductances, and at least one negative resistance in series with one of the resonators, a dual response filter is formed by providing an auxiliary conductor line, wherein an input end of the filter is connected to an electrical ground, forming a resonator with its own resonant frequency less than the cut-off frequency fc of the low-pass filter, the auxiliary line extending from this end along and away from the main line. The resonator forms by coupling a rejection filter around the resonant frequency within the bandwidth in the low-pass filter.

Abstract: The invention relates to a selective active low-pass filter and to a method for improving the selectivity of such a filter. The method includes centering, in the center of a network, the resonant element whose frequency is closest to the cutoff 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.

Abstract: The invention relates to a filtering network in HR-Si silicon technology defined by at least one cut-off frequency and comprising an input terminal for receiving the signal to be filtered and an output terminal for delivering a filtered signal. The network comprises a first ground line connected by its ends to first and second ground points connected directly to the ground plane, a second ground line connected via its ends to third and fourth ground points directly connected to the ground plane, a plurality of L/C resonant elements connected in parallel and linked via one end to one of the two ground lines and via the other end between them, by means of coupling inductors which thus create transmission zeros.

Abstract: The present invention relates to an active band stop filter comprising a filter input and a filter output which are linked by a transmission line LT, a resonator RE coupled to the transmission line and connectable to a load impedance. Between the resonator and the load impedance there is mounted a means of activation of the filtering function in a chosen operating band. The filter is useable in multistandard terminals.

Abstract: 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.

Abstract: The channel filter includes at a least one basic bandpass filter centred on the frequency of the channel, in series with two cascade-connected reflective filters whose bandwidths are located either side of the basic bandpass filter encompassing the channels adjacent to the channel. A reflective filter can include a 90° directional coupler combined with a bandpass filter designed to ensure transfer matched to the load impedance of the coupler with the input of the bandpass filter connected to a directional coupler output port, the input of the directive filter being formed by input port of the coupler and the output of the directive filter being formed by a port recovering the bandpass filter reflection coefficient. The invention applies in particular to the implementation of the DVB-T and DVB-H standards aimed at receiving digital television programs from fixed or mobile multistandard terminals such as mobile telephones, PDAs or other multimedia receivers.

Abstract: The invention relates to a filtering network in HR-Si silicon technology defined by at least one cut-off frequency and comprising an input terminal for receiving the signal to be filtered and an output terminal for delivering a filtered signal. The network comprises a first ground line connected by its ends to first and second ground points connected directly to the ground plane, a second ground line connected via its ends to third and fourth ground points directly connected to the ground plane, a plurality of L/C resonant elements connected in parallel and linked via one end to one of the two ground lines and via the other end between them, by means of coupling inductors which thus create transmission zeros.

Abstract: The invention relates to a dual-response stopband filter as well as to a filtering device comprising such a filter. The dual-response stopband filter comprises between the input terminal and the filter output a first direct channel and a second channel, known as a secondary channel, coupled with the first channel and forming a resonant element. The filter further comprises, integrated on the first direct channel, a selective low-pass filter to reject a first selected frequency band and, integrated on the second channel a variable capacitor to form the stopband filter of a second frequency band that can be determined. The switching device is associated with the first channel to switch the low-pass filter and the second channel to switch the stopband filter.

Abstract: 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.

Abstract: The channel filter includes at a least one basic bandpass filter centred on the frequency of the channel, in series with two cascade-connected reflective filters whose bandwidths are located either side of the basic bandpass filter encompassing the channels adjacent to the channel. A reflective filter can include a 90° directional coupler combined with a bandpass filter designed to ensure transfer matched to the load impedance of the coupler with the input of the bandpass filter connected to a directional coupler output port, the input of the directive filter being formed by input port of the coupler and the output of the directive filter being formed by a port recovering the bandpass filter reflection coefficient. The invention applies in particular to the implementation of the DVB-T and DVB-H standards aimed at receiving digital television programmes from fixed or mobile multistandard terminals such as mobile telephones, PDAs or other multimedia receivers.