Ultra-wideband (UWB) bandpass filters play a key role in the development of UWB systems. In this paper, we present a review on their development since the release of UWB band for indoor and hand-held systems by Federal Communications Commission (FCC) in 2002.

Performance evaluation of time-hopping UWB using various modulation techniques has been proposed. Then the performance improvement is analysed based on the BERs of various existing methods. Recently a new method called TH-BPSK UWB system is proposed which provides a better performance than all other existing systems. The literature survey discusses all the existing techniques of UWB communication.

The aim of this document it to present an overview of some recent research activities on ultra–wideband (UWB) channel modeling. Compared to models introduced in DRB1.2, recent research was focused on more sophisticated tools to model UWB channels, like information theoretic arguments. Physical modeling of UWB channels was also investigated. Reference D.xx.xx Issue n.m 4 November 2006 507325 NEW...

-In ultra-wideband (UWB) impulse radio (IR) technology, it is important that the pulse shape be adjusted such that the power spectral characteristics not only satisfy the standard limits, but also be characterized by deep nulls at the locations of existing narrowband primary users. Cognitive Radio Technology (CR) is presented as a viable solution for UWB systems for narrowband interference supp...

Power control is a critical parameter for the design and evaluation of UWB-based WPAN networks due to its distributed control nature and non-fixed topology. The main issues in UWB PC are the channel gain fluctuations induced by indoor channel fluctuation and interference arising from narrowband systems. In this paper we introduce a joint PHY/MAC technique for DS-UWB power control design by expl...

In this paper, the significance of linearity for UWB front-end circuit is discussed. The effects of strong narrow band interferer on UWB signal are investigated. Wideband linearization techniques for UWB LNA are first proposed in this work. A high linearity UWB LNA is designed in TSMC 0.18μ CMOS process The simulation results show that the designed LNA exhibits very high IIP3 (6.9~13.8 dBm) whi...

In this paper, we present an ultra-wideband (UWB) pulse generator based on the step recovery diode. The principle of operation and the architecture of the developed pulse generator are explained. Furthermore, hardware implementation issues and the details on the generated UWB pulse including its peak voltage equal to 8.9 V, its full width at half maximum (fwhm) equal to 240 ps, and frequency sp...

Ultra Wide Band (UWB) technology is a developing wireless technology which promises high data rate short distance communication. In this paper, propose an advanced method for generating UWB signal for many UWB related applications. Important area of application is Wireless Local Area Network (WLAN). The basic idea of the work is to develop pulses of nanosecond range for the UWB transmission and...

هدف: هدف از پژوهش حاضر مقایسۀ واکنش ­پذیری هیجانی و نظریه ذهن کودکان بر اساس سبک ­های ابرازگری مادرانشان بود. روش: روش توصیفی نوع علّی-مقایسه­ ای بود در دو گام به صورت آنلاین انجام رسید. ابتدا با استفاده نمونه ­گیری دسترس، تعداد 105 نفر مادرانی که نمرات آن­ها هر یک پرسشنامه کینگ امونز (1990)، دوسوگرایی (1990) کنترل راجر نشوور (1987) انحراف استاندارد بالاتر میانگین دست آمد (در گروه 35 نفر) دوم وا...

The performance of DS-UWB and TH-UWB for a single-user link is compared for a data rate of 100 Mbps using the newly proposed, realistic UWB channel model from IEEE P802.15. The performance of suboptimal, fractionally spaced (FS), coherent Rake receivers with a pulse matched filter is evaluated with numerical simulations when different channel estimation algorithms, suitable for coherent detecti...