In this paper, a wideband electronic beamforming concept applicable for UWB short pulse systems is derived and experimentally demonstrated. In particular, a Finite Impulse Response (FIR)-filter based beamforming network is configured such that an antenna array yields a desired radiation pattern within a predefined frequency range. An experimental verification of a wideband transmission system i...

Log-periodic array antennas have been investigated over a long period of time, the reason for the same being its provision of a constant radiation performance and good reflection coefficient performance over a wide frequency band, which can be considered as an important characteristic of this type of antennas. It created a high impact on development of new generation antennas with advanced feat...

Electromagnetic ultra-wideband (UWB) sensing and imaging provide perspectives for early-stage breast cancer detection. This paper deals with practical challenges of real measurements. We present an experimental setup for breast phantom trials based on M-sequence radar technology and short active dipole antennas. It combines short impulse responses, appropriate fidelity and very small antenna di...

The Army Research Laboratory (ARL), in collaboration with the Air Force Phillips Laboratory, has been developing the fabrication process for lateral topology, highpower photoconductive semiconductor switches (PCSS) used in phased-array, ultrawideband (UWB) sources. This work presents issues associated with the development of these switches. First-generation devices (1.0 em gap spacing) have bee...

This paper presents a theory of imaging objects behind layers of scattering media. The transmitter is a focused array or an aperture emitting a short pulse. The scattered pulse is received by a focused array or aperture. The received signal consists of two components: the pulse scattered from a random medium and from the target, and these two components can be distinguished by the use of ultra ...

ULTRA-WIDEBAND (UWB) transmission has recently received significant attention in both academia and industry for applications in wireless communications. UWB technology has many benefits, including high-data rate, availability of low-cost transceivers, low-transmit power, and low interference. It operates with emission levels that are commensurate with common digital devices such as laptops, pal...

On February 14, 2002, the Federal Communications Commission (FCC) of the United States adopted the First Report and Order that permitted the commercial operation of ultra wideband (UWB) technology (FCC, 2002). The FCC allocated a bandwidth of 7.5GHz, i.e. from 3.1GHz to 10.6GHz, to unlicensed use for UWB applications. Ultra Wideband is defined as any communication technology that occupies great...

UWB impulse radios (UWB-IR) have attracted increasing interest due to their potential to propose high user capacity with low-complexity and low-power transceivers (Win & Sholtz, 2000). It is approved by the Federal Communications Commission’s (FCC) Report in which the UWB spectral mask is released and published in February 2002. Most of these benefits initiate from the distinctive characteristi...

In this paper, the impact of chip duty factor (DF) on direct sequence (DS), time hopping (TH) and hybrid DS-TH ultra wideband (UWB) systems is investigated in realistic environments. Rake receivers are designed to perform energy capture (EC) on received UWB signals over multipath and multi-user environment in the presence of narrowband interference. It is found that by applying lower DF in the ...

For many applications, wideband signals are exploited for localization. A wideband signal is any signal whose energy is distributed over a bandwidth that is large in comparison to the signal’s center frequency. For example, ultrawideband (UWB) noise radars use wideband offering low probability of detection (LPD), while achieving good target detection and high resolution [1]. In the acoustic veh...