Ultra-Wideband Technology: Characteristcs, Applications and Challenges

Ultra-wideband (UWB) technology is a wireless communication technology designed for short-range applications. It is characterized by its ability to generate and transmit radio-frequency energy over an extensive frequency range. This paper provides an overview of UWB technology including its definition, two representative schemes and some key characteristics distinguished from other types of communication. Besides, this paper also analyses some widely used applications of UWB technology and highlights some of the challenges associated with implementing UWB in real-world scenarios. Furthermore, this paper expands upon UWB technology to encompass terahertz technology, providing an overview of the current status of terahertz communication, and conducting an analysis of the advantages, challenges, and certain corresponding solutions pertaining to ultra-wideband THz communication

Ultra wideband: applications, technology and future perspectives

Ultra Wide Band (UWB) wireless communications offers a radically different approach to wireless communication compared to conventional narrow band systems. Global interest in the technology is huge. This paper reports on the state of the art of UWB wireless technology and highlights key application areas, technological challenges, higher layer protocol issues, spectrum operating zones and future drivers. The majority of the discussion focuses on the state of the art of UWB technology as it is today and in the near future

Experimental evaluation of UWB indoor positioning for indoor track cycling

Accurate radio frequency (RF)-based indoor localization systems are more and more applied during sports. The most accurate RF-based localization systems use ultra-wideband (UWB) technology; this is why this technology is the most prevalent. UWB positioning systems allow for an in-depth analysis of the performance of athletes during training and competition. There is no research available that investigates the feasibility of UWB technology for indoor track cycling. In this paper, we investigate the optimal position to mount the UWB hardware for that specific use case. Different positions on the bicycle and cyclist were evaluated based on accuracy, received power level, line-of-sight, maximum communication range, and comfort. Next to this, the energy consumption of our UWB system was evaluated. We found that the optimal hardware position was the lower back, with a median ranging error of 22 cm (infrastructure hardware placed at 2.3 m). The energy consumption of our UWB system is also taken into account. Applied to our setup with the hardware mounted at the lower back, the maximum communication range varies between 32.6 m and 43.8 m. This shows that UWB localization systems are suitable for indoor positioning of track cyclists

Medical Application of Ultra-Wideband Technology

This chapter deals with the applications of ultra-wideband technology, especially for medical scope, and the most features and advantages that made it useful in this scope. Also, the chapter has been included with the most important medical applications of UWB technology. Ultra-wideband radar for angiography and UWB glucometer are the main applications which will be explained in this chapter. The exposure for safety aspects, the dielectric properties of human tissues, blood dielectric properties measurement using open-ended coaxial probe experiment to improve the blood image, and the ideal ultra-wideband pulses’ shape, width, and repetition time that are used for medical applications have been illustrated. Finally, the results (figures, tables, and experiment results), conclusions, and discussions have been mentioned

Performance analysis of ultra wide band indoor channel

This thesis report is submitted in partial fulfillment of the requirements for the degree of Bachelor of Science in Computer Science and Engineering, 2008.Cataloged from PDF version of thesis report.Includes bibliographical references (page 41).Research on wireless communication system has been pursued for many years, but there is a renewed interest in ultra-wideband (UWB) technology for communication within short range, because of its huge bandwidth and low radiated power level. This emerging technology provides extremely high data rate in short ranges but in more secured approach. In order to build systems that realize all the potential of UWB, it is first required to understand UWB propagation and the channel properties arise from the propagation. In this research, the properties of UWB channel for indoor industrial environment was evaluated. A few indoor channel models have been studied so far for different environments but not for indoor industrial environment and various data rates are obtained according to wireless channel environments. Therefore, an accurate channel model is required to determine the maximum achievable data rate. In this thesis, we have proposed a channel model for indoor industrial environment considering the scattering coefficient along with the other multipath gain coefficient. This thesis addresses scattering effect while modeling UWB channel. Here, the performance of UWB channel model is analyzed following the parameters, such as power delay profile and the temporal dispersion properties which are also investigated in this paper.Kazi Afrina YasmeenA. K. M. WahiduzzamanMD. Ahamed ImtiazB. Computer Science and Engineerin

Design and Development of a Compact and Vialess Microstrip Ultra-Wideband Bandpass Filter

In radio frequency and microwave systems, filters are the most essential component to select the required signals. They are built together with other components such as mixers, amplifiers, oscillators and switches. Filters work by blocking the unwanted signals and allowing the desired signals through them before feeding it into other components or devices. In the latest interest and future radio frequency and microwave high speed communication technology like Ultra-Wideband (UWB), a bandpass filter with large bandwidth (> 500 MHz) is required to fulfill the specifications. This is due to the UWB format signal which uses very short time pulse wave within 1.0 ns to 0.1 ns. This thesis presents theories, methods, parameters, simulations and measurements of designed and development of bandpass filters to support UWB communication systems. There are four types of bandpass filters which are designed and developed to operate within 3.1 GHz to 10.6 GHz to support the UWB frequency range specification.Initially, the designed model is derived from J-inverter which it is a transformation of low pass to bandpass Chebyshev filter. Type of response is chebyshev since it is able to perform an equal-ripple return loss response in the whole passband. The equal-ripple return loss response can keep the insertion loss almost flat in the whole pass band and sharp-out-of-band rejection response. In the thesis, bandpass filters are designed and developed based on five poles quarterwavelength short-circuited stubs model. The model is theoretically capable to expand the frequency bandwidth by tuning its h (interior admittance level of the stubs) factor. The related mathematical equations are applied into mathematical software to speed up the optimization of h factor and obtain the required admittance level for stubs and transmission lines. The first bandpass filter has successfully shown the expansion in frequency bandwidth to support Ultra-wideband specifications. The filter uses five vias to short-circuit stubs to the ground. Stubs, transmission lines admittance and h are tuned slightly to expand the fractional bandwidth (FBW) more than 100 %. The measured scattering parameters are |S21| = 1.27 dB and S11 = -7.8 dB respectively. The second bandpass filter is improved by reducing the short-circuited via elements. First and second stubs are shared on the first via while fourth and fifth stubs share on the third via. Only third stub has its own via thus creating new transformation filter shape nicknamed as “Butterfly”. This new shaped has 109 % of measured fractional bandwidth, lower scattering parameters |S21| which is below than 0.85 dB and S11 is better than -11.6 dB. Besides, it also reduces the number of via insertion in microstrip fabrication process.The third bandpass filter has totally eliminates vias and thus simplifies the microstrip fabrication process. Vias are replaced by microstrip patched capacitors. At microwave frequencies, these capacitors are parasitic elements and their parameters contribute to the successful performance in S-parameters measurement. The measured scattering parameters |S21| and S11 are better than 1 dB and -16.9 dB respectively. The fourth filter is improved in terms of scale dimension and group delay compares to the third filter. The structure is via-less and the filter uses less microstrip patch capacitors to perform compact size with “Butterfly” shape. By reducing microstrip patched capacitors, the filter shows better S-parameters measurements in the UWB passband with the lowest scattering parameters |S21| 0.53 dB and S11 of -14.8 dB. The group delay varies minimum within 0.47 ns in the whole UWB pass band

A design of reconfigurable filtering-antenna for ultra-wideband applications

Antenna is a main element in the UWB systems to transmit and receive signals. However, there are challenges to meet the requirements for a suitable UWB antenna compare to other narrowband antennas such as high data rate, omnidirectional radiation pattern and wide frequency bandwidth. Since the UWB technology is facing the interference problem with other narrow band signals such as WiMAX, WLAN and HiperLAN, which severely degrade the performance of the receiver in the UWB system, thus the conventional UWB system is integrated with bandstop filter in separated model from the antenna, which leads to increase complexity, cost, weight and loss. Therefore, researchers tend to integrate resonant structure in the antenna design to produce band notch characteristics and filter out unwanted signals using different techniques such as defected ground structure (DGS), defected patch structure (DPS) and resonant structure beside the feedline of the antenna design. However, the disadvantages of these techniques are the excessive band rejection, which rejects needed frequencies, and the fixed band notch whether the interfering signal exists or not, which may reduce the performance of the UWB system, thus producing sufficient and switchable band notch is a challenging issue to improve the performance of the UWB system. Therefore, in this research, a modified monopole antenna is designed to produce UWB bandwidth using microstrip transition in the feedline and block with triangular slot on each side of the circular patch. The modified monopole antenna is integrated with resonant structures to produce band notch characteristics and filter out unwanted signals. Two techniques based on defected microstrip structure (DMS) and two double split ring resonator (DSRR) are integrated with the antenna design individually. The DMS is embedded in the feedline of the antenna design to produce single band notch. The two DSRR are loaded above the ground plane of the antenna design to produce dual band notches. A PIN diode is employed in the resonant structure to achieve frequency reconfiguration. The results show that the modified monopole antenna exhibits wide bandwidth (129.5%) with a return loss better than -15 dB, high frequency skirt selectivity ranging from 3 to 14 GHz, which covers the entire UWB frequency band (3.1-10.6 GHz), peak gain of 5.3 dB and omnidirectional radiation pattern. The new integrations of filtering-antenna using DMS and DSRR provide stable omnidirectional azimuth pattern and sharp band notches, which are sufficient to remove unwanted signals and keep wanted signals. The simulated and measured results show a good agreement, where the proposed filtering-antenna using DMS exhibits wide bandwidth with switchable band notch at 5.5 GHz (WLAN), and the filtering-antenna using two DSRR exhibits wide bandwidth with switchable sharp band notches at 3.5 GHz (WiMAX) and 5.55 GHz (HiperLAN2)