摘要:
The invention relates to processes and devices which make it possible to directly modulate an RF carrier with a quadrature signal. It consists in filtering (504) this quadrature signal around zero so as to introduce alternately (507, 508) on each of the channels a low-frequency subcarrier that will serve as reference. Each of these channels is alternately demodulated in a synchronous manner (519) cosine-wise and sine-wise. The demodulation signal is filtered (523) so as to recover the subcarrier marred by modulation errors. The measurement of these errors (524) allows feedback correction (503) of the quadrature signal. It makes it possible to perform the major part of the operations in the digital processor (501) and enables direct vector modulation to be made possible at millimeter frequencies.
摘要:
The present invention relates to a FINLINE type microwave band-pass filter comprising a waveguide provided with an insulating substrate placed in an E plane of the guide and comprising on at least one of the surfaces, conductive inserts electrically connected to the internal surfaces of the guide which support the substrate and which determine by their dimensions and their positioning on the substrate a Chebyshev type filter response curve. The filter includes at least one cavity in perpendicular short circuit to the substrate, the positioning and the dimensions of the cavity determining a transmission zero on the filter response curve for attenuating the frequencies situated around this zero. Such a filter is used in particular in transmission terminals operating in the Ka band.
摘要:
The present invention relates to a multiband planar antenna consisting of at least one resonator formed of an element having a closed shape made on a substrate and dimensioned so as to operate in its fundamental mode at the resonant frequency of the lowest band. The resonator is fed by a feed line in such a way as to operate in all the higher modes. The resonator comprises means for modifying the resonant frequencies of the various modes in such a way as to cover the bands concerned.
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 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.
摘要:
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. Each ground line forming inductive elements via inductances the network comprises capacitive elements in series with at least some of said inductive elements, the value of the capacitive elements being selected so that the resonant frequency of the inductive and capacitive elements in series corresponds to a frequency lying outside of the bandwidth.
摘要:
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. Each ground line forming inductive elements via inductances the network comprises capacitive elements in series with at least some of said inductive elements, the value of the capacitive elements being selected so that the resonant frequency of the inductive and capacitive elements in series corresponds to a frequency lying outside of the bandwidth.
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 invention relates to a dual-band planar antenna formed by at least one slot of closed shape fabricated on a printed substrate having a perimeter equal to kλf, and two supply lines supplying power to the slot via two accesses separated by (2m+1)λf/4, where λf is the guided wavelength in the slot and k and m integers greater than 0, the slot comprising means modifying the operating frequency, one of the supply lines being situated on the said means. The invention is especially applicable to antennas used in domestic wireless networks (IEEE802-11a or Hyperlan 2 standards.
摘要翻译:本发明涉及一种双带平面天线,其由封闭形状的至少一个狭缝形成,其制造在印刷基板上,其周长等于klambda,并且两个电源线通过两个 由(2m + 1)λ/ f / 4分开的访问,其中λ是在时隙中的引导波长,并且k和m个整数大于0,所述时隙包括装置 修改工作频率,其中一条供应线位于所述装置上。 本发明特别适用于国内无线网络(IEEE802-11a或Hyperlan2标准)中使用的天线。
摘要:
The present invention relates to a planar antenna carried by a substrate including a slot (11) consisting of a closed curve dimensioned in order to operate at a given frequency and fed by a feed line (12) positioned so that the slot lies in a short-circuit plane of the feed line. This antenna includes, in parallel on the slot 11, at least one switching means 13 capable of assuming a closed state or an open state so as to modify the operating frequency band of the planar antenna. This antenna is particularly suitable for domestic wireless networks.