**Author details**

Mongkol Meeloon *Department of Special Investigation (DSI), Thailand* 

Sarawuth Chaimool and Prayoot Akkaraekthalin *King Mongkut's University of Technology, North Bangkok, Thailand* 

## **6. References**

Meeloon, M.; Akkaraekthalin, P. (2007). Broadband bandpass filters using slotted linear tapered-line resonators for improving upper stopband performances, *Proceedings of EECON-30 30th Electrical Engineering conference*, pp.1109-1112, Kanchanaburi, Thailand, 2007

**Chapter 14** 

© 2012 Taha and Ramon, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2012 Taha and Ramon, licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**UWB Coexistence with** 

**3G and 4G Cellular Systems** 

Ahmed Bazil Taha and Miguel Calvo Ramon

Additional information is available at the end of the chapter

The Federal Communications Commission (FCC) agreed in February 2002 to allocate 7.5 GHz of spectrum, in the 3.1 GHz to 10.6 GHz frequency band, for unlicensed use of ultra wide band (UWB) devices for communication applications. The move represented a victory in a long hard-fought battle that dated back decades. With its origins in the 1960s, when it was called time-domain electromagnetics, UWB came to be denoting the operation of sending and receiving extremely short bursts of RF energy. With its outstanding ability for applications that require precision distance or positioning measurements, as well as highspeed wireless connectivity, the largest spectrum allocation ever granted by the FCC is unique because it overlaps other services in the same frequency of operation. Previous spectrum allocations for unlicensed use have opened up bandwidth dedicated to unlicensed devices based on the assumption that operation is subject to the following two conditions:

1. The device will not cause harmful interference to other systems. Thus, the UWB interferences should not seriously degrade, obstruct, or repeatedly interrupt other radio

2. The device must accept any interference received from any licensed system, including interference that may cause undesired operation. This means that devices using unlicensed spectrum must be designed to coexist in an uncontrolled environment.

Devices using UWB spectrum operate according to similar rules, but they are subject to more stringent requirements because UWB spectrum underlays other existing licensed and unlicensed spectrum allocations. In order to optimize spectrum use and reduce interference to existing services, the FCC's regulations are very conservative and require very low

The UWB spectrum consists of three different parts as given below:

http://dx.doi.org/10.5772/47365

communication systems.

emitted power.

**1. Introduction** 

