نتایج جستجو برای: uwb
تعداد نتایج: 4839 فیلتر نتایج به سال:
بسیاری از فرستندههای رادیویی UWB برای نرخ تکرار پالس خاصی طراحی شدهاند. به این معنی که چگالی طیفی توان در این فرستندهها، بهطور کامل با ماسک توان FCC منطبق نبوده و بهازای برخی از نرخهای تکرار پالس، از محدوده توانی آن تجاوز میکند. این مسئله در کاربردهای بیسیم برد کوتاه که به نرخ تکرار پالس متغیر نیاز دارند اهمیت به سزایی دارد. در این مقاله، یک فرستنده IR-UWB با چگالی طیفی توان تطبیقپذیر ...
This paper presents the design of a 2-16 GHz ultra wide band low noise amplifier (UWB LNA). The proposed LNA has a gain of 11.5 ± 0.85 dB with NF less than 2.82 dB. Good input and output impedance matching, good isolation and linearity are achieved over the operating frequency band. The proposed UWB LNA consumes 18.14 mW of power from 1.8V supply. This UWB LNA is designed and simulated in 0.18 ...
Ultra-Wide Band (UWB) was presented as a promising radio technology. Because of their large bandwidth, UWB networks are supposed able to deliver high data rates at short ranges. But after analyzing measurements many works observed saturation of the number of channel Degrees of Freedom (DoF) versus bandwidth. This motivates the work presented in this paper where we focus on sub space behavior to...
Radio communications via channels already occupied by traditional telecommunication systems can be achieved by using ultrawideband (UWB) radio where extremely wideband wavelets are used in order to reduce the power spectral density (psd) of transmitted signal. Since the recovery of these UWB carriers is not feasible, noncoherent demodulation techniques have to be used. The letter evaluates and ...
UWB (Ultra-Wideband) is one of the WPAN (Wireless Personal Area Network) Technologies; its main applications include imaging systems, vehicular radar systems and communications and measurement systems. Ever since the FCC released unlicensed spectrum of 3.1-10.6 GHz for UWB application in 2002, UWB has received significant interest from both industry and academia. Comparing with traditional narr...
This paper presents an overview of ultrawideband (UWB) communications systems, i.e., systems with very large relative and/or absolute bandwidth. The large bandwidth and low power spectral density mandated for UWB systems allows to use them as overlay over existing (legacy) systems, i.e., they can be used in the same frequency range as existing systems without causing undue interference. We also...
An ultra-wideband (UWB) power divider is designed in this paper. The UWB performance of this power divider is obtained by using a tapered microstrip line that consists of exponential and elliptic sections. The coarse grained parallel micro-genetic algorithm (PMGA) and CST Microwave Studio are combined to achieve an automated parallel design process. The method is applied to optimize the UWB pow...
This paper presents an approach for a precise 2D-localization of a mobile station in indoor scenarios by one single base station only. In the approach both, the Direction of Arrival (DoA) and the Time of Arrival (ToA), are estimated using UWB beamformers at both sides of the link. The article describes the algorithm, as well as the required hardware. A duallinear polarized, directive UWB antenn...
There are several types of ultra wideband (UWB) radar systems which can be used with advantage for the purpose of detection and tracking of persons moving behind obstacles. The intention of this paper is to test in real conditions performance of an impulse UWB radar in comparison with an M-sequence UWB radar for the mentioned application. For that purpose a through-wall measurement with two per...
Cooperative diversity has emerged as a major technique of providing gains from spatial diversity to devices/terminals. While ultra-wideband (UWB) offers high information rates for wireless communication and sensor networks, the EIRP limits on UWB devices severely affects its coverage radius. In this paper, a low complexity cooperative diversity scheme for UWB channel is proposed. The scheme use...
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