Abstract:
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.
Abstract:
L'antenne décrite utilise un premier condensateur formé par un segment conducteur (17) disposé au-dessus d'un plan horizontal (11) et des condensateurs adjacents connectés en série formés sur le plan horizontal (11). Les condensateurs adjacents sont connectés au plan horizontal par des circuits syntonisés (31, 26), produisant un couplage supplémentaire des champs E à travers le premier condensateur et les condensateurs adjacents et empêchant le shuntage des champs E.
Abstract:
An active antenna capable of transmitting and receiving a wireless signal of a low frequency band and a mobile communication terminal having the active antenna, are provided. The active antenna includes an antenna element (10) which transmits and receives a wireless signal, a filter (20) which filters the wireless signal being received at the antenna element such that a wireless signal belonging to a frequency band lower than the operating frequency of the antenna element is passed, and an amplifier (30) which amplifies the wireless signal being passed through the filter. As a result, the size of the antenna can be greatly reduced, by the use of an active antenna which receives wireless signals of low frequency bands. Additionally, a more compact mobile communication terminal can be provided, because wireless signal of both high frequency bands and low frequency bands can be transmitted and received at one antenna.
Abstract:
An antenna employing a first capacitor formed by a conductive segment (17) disposed above a ground plane (11) and serially connected adjacent capacitors formed over the ground plane (11). The adjacent capacitors are connected to the ground plane by tuned circuits (31, 26), resulting in additive coupling of the E fields across the first and adjacent capacitors and the prevention of E field shunting.
Abstract:
Dispositif de détection de signal ultra large bande, caractérisé en ce qu'il comporte : - Un circuit de réception de signal, - Un circuit (3) de division du signal reçu en plusieurs sous-bandes de fréquence, - Un circuit (8) de détermination de l'amplitude et de la durée du signal reçu dans chaque sous-bande de fréquence, - Un circuit (8) de comparaison de l'amplitude du signal reçu dans chaque sous-bande de fréquence avec un seuil d'amplitude, - Un circuit (8) de comparaison de la durée du signal reçu dans chaque sous-bande de fréquence avec un seuil temporel, et - Un circuit (8) de décision qui détermine que le signal reçu est de type ultra large bande si l'amplitude du signal reçu dans chaque sous-bande de fréquence est supérieure au seuil d'amplitude et si la durée du signal reçu dans chaque sous-bande de fréquence est inférieure au seuil temporel.
Abstract:
An active antenna capable of transmitting and receiving a wireless signal of a low frequency band and a mobile communication terminal having the active antenna, are provided. The active antenna includes an antenna element (10) which transmits and receives a wireless signal, a filter (20) which filters the wireless signal being received at the antenna element such that a wireless signal belonging to a frequency band lower than the operating frequency of the antenna element is passed, and an amplifier (30) which amplifies the wireless signal being passed through the filter. As a result, the size of the antenna can be greatly reduced, by the use of an active antenna which receives wireless signals of low frequency bands. Additionally, a more compact mobile communication terminal can be provided, because wireless signal of both high frequency bands and low frequency bands can be transmitted and received at one antenna.