Active antenna

About: Active antenna is a research topic. Over the lifetime, 2246 publications have been published within this topic receiving 26493 citations.

Energy-efficient active antenna arrangement

Abstract: Energy-efficient active antenna arrangement (7) comprising an active antenna controller (5) for controlling TRX module sets comprising a master TRX module (2) and one or more slave TRX modules (3) and antenna elements (1,1'). The slave TRX modules (3) can be switched on/off by the active antenna controller (5) according to traffic load requirements, such that the output power of the antenna can be adjusted to reduce power consumption and the radiation pattern of the antenna remains substantially unchanged.

Compact wideband integrated active slot antenna amplifier

Abstract: The design and performance of a linear tapered slot antenna integrated directly with a FET amplifier are presented. The measured radiation patterns of the antenna are linear with crosspolarisation levels of 13dB down in both the E and H plane. The measured gain of the antenna is more than 14 dB over a bandwidth of 1.75 GHz. Compared with a passive antenna, the active antenna has an extra gain of 7 dB at 9.2 GHz

Method of forming the radiation pattern of a high efficiency active antenna for an electronically-scanned radar, and an antenna implementing the method

Abstract: A method of forming the radiation pattern of a high efficiency active antenna for electronically-scanned radar, wherein its illumination laws, and thus its radiation patterns are dissociated in transmission and in reception; and equal amplitude illumination is provided in transmission in order to maximize the efficiency of the transmit amplifiers which are all identical, thereby minimizing their DC energy consumption and their dissipation. The invention is particularly suitable for use in space radars.

Space-Time Index Modulation

Abstract: In this paper, we present a new multi-antenna modulation scheme, termed as {\em space-time index modulation (STIM)}. In STIM, information bits are conveyed through antenna indexing in the spatial domain, slot indexing in the time domain, and $M$-ary modulation symbols. A time slot in a given frame can be used or unused, and the choice of the slots used for transmission conveys slot index bits. In addition, antenna index bits are conveyed in every used time slot by activating one among the available antennas. $M$-ary symbols are sent on the active antenna in a used time slot. We study STIM in a cyclic-prefixed single-carrier (CPSC) system in frequency-selective fading channels. It is shown that, for the same spectral efficiency, STIM can achieve better performance compared to conventional orthogonal frequency division multiplexing (OFDM). Low-complexity iterative algorithms for the detection of large-dimensional STIM signals are also presented.

Active antenna performance limitation

Abstract: Many amplifier designs have been proposed for use with electrically small antennas in receiving applications. A study of pertinent noise figure and available power gain equations shows that performance is strongly influenced by antenna resistance. Low values of antenna resistance limit noise performance, and a study of antenna Q shows that only a limited increase in resistance can occur.