Rf And Wireless Technology Know It All Pdf Search
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In this conceptual paper, we discuss the concept of hospital of the future HoF and the requirements for its wireless connectivity.
- Wireless Communications for the Hospital of the Future: Requirements, Challenges and Solutions
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- RF Engineering for Wireless Networks, Daniel M. Dobkin
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Wireless Communications for the Hospital of the Future: Requirements, Challenges and Solutions
Not a MyNAP member yet? Register for a free account to start saving and receiving special member only perks. Wireless is a short-cut terminology for electromagnetic EM waves transmitted through free space without wires. EM waves are fundamental in nature. As waves, they are sinusoidal fields defined by their frequency, which can have any value from very slow vibrations to ultra-rapid vibrations.
The EM waves engineers create are radiated by vibrating electrons, electrically driven to emit at the characteristic frequencies needed for wireless technology. Table D. The wavelengths of EM waves are related to the reciprocal of their frequencies. Those EM waves with wavelengths between 1 m and 1 mm are called microwaves.
Millimeter waves are the name given to the highest frequencies used for wireless, with wavelengths from 0. The terms airwaves and radio waves are sometimes used for EM waves, and the entire range of EM frequencies available for applications is called spectrum.
Governments all over the world control their own airwaves by allocating separate bands of spectrum for separate applications. EM waves can be used to transmit information if the waves are modulated their characteristics changed with time. Communication requires modulating the EM waves, resulting in a spread of frequencies bandwidth that carry the information surrounding the carrier frequency that defines the unmodulated wave.
Because the bandwidth is a well-defined fraction of the carrier frequency, it can be seen that higher carrier frequencies can have larger bandwidth and can transmit more information.
Today, much of the modulation has a digital format. The first public awareness of the importance of wireless telecommunication was the distress signals broadcast by the sinking Titanic in These signals were picked up by a nearby ship, beginning the famous rescue operation. The resulting publicity demonstrated to the world that safety required specific frequencies to be reserved for specific applications, such as SOS emergencies.
Thus began government control of airwaves. The military buildup due to World War I caused wireless frequencies to be reserved primarily for government use. As technology rapidly improved, higher frequencies could be used. By the following year, the spectrum range of available frequencies was assigned out to kHz 1.
Because EM waves easily travel across boundaries between countries, beginning in the s, governments around the globe have negotiated within the International Telecommunications Union ITU 1 to allocate different frequency ranges for different applications while providing for compatibility. Radio services that have been allocated spectrum include fixed service e. Through extensive negotiation, the entire radio spectrum has been divided into specific blocks of frequencies for each application; most often, several blocks at different carrier frequencies can service the same application.
These blocks of frequencies are then allocated by most countries. In the U. When the same band is shared for different applications, both entities need to agree. Initially, there was enough spectrum for everyone, and allocations were made by determining the best use for each band based on both availability and the state of the relevant technology at the time.
However, in the rapid growth in personal communication systems and the impending explosion of mobile cell phone usage forced re-consideration of band allocation within the spectrum.
The FCC introduced the idea of auctioning these frequency allocations to the highest bidders, with the understanding that profits could be returned to the federal budget.
Internationally harmonized global spectrum allocations allow manufacturers to develop worldwide markets, as demonstrated through the widespread adoption and commercial success of IEEE standards for wireless local area networks WLANs in , and more recent agreements that all WLANs operate in the same globally allocated spectrum. WLAN succeeded because there was universal international agreement for the use of the 2.
Without international spectrum agreements, new wireless technologies will founder for lack of a global market.
Countries whose engineers participate in the standard-setting of ITU have more political clout to persuade the global community to choose standards that are consistent with the technology used in their country.
The first auction assigned 50 to kHz bandwidth blocks within the MHz range of carrier frequencies nationwide. Ten national licenses were provided for a total bandwidth of 0. A few days later, the FCC auctioned off the blocks of higher bandwidth near the MHz carrier frequency to metropolitan service areas with the idea that these blocks could be reused by different metropolitan areas.
The FCC planned for them to be used for interactive video and data services. In fact, these blocks were broken up by the carriers to enable them to handle multiple mobile phones operating simultaneously in the same cell. The rapid adoption of cell phones by the general population made apparent the value of owning spectrum bandwidth assignments.
Only 4 months later, a similar auction assigning carrier frequencies of 1. A few of the relevant later auctions are described below. A very high carrier frequency of This was designed for direct-to-home satellite service to permit delivery of digitally compressed TV signals to individual households by means of an external receiving antenna.
The external antenna was required because waves at this high frequency do not readily pass through walls. By , Auction 30 was designed for outdoor fixed point-to-point and point-to-multipoint communications, such as between cell towers.
The 39 GHz carrier frequency was designated with 14 channels each with bandwidth of MHz. Usage of these frequencies requires highly directional antennas to counteract propagation losses while enabling point-to-point communication. As TV moved from analog to digital, more bandwidth previously used for analog TV transmissions could be repurposed for wireless telecommunications applications.
The frequency band from MHz had originally been reserved for broadcasting TV. By , concerns about improving homeland security pointed to the need for a network on a single frequency band over which all first-responders could wirelessly communicate; at the time, different responders typically used different frequency bands. Congress created the First Responder Network Authority FirstNet with the mission to provide a single interoperable platform for emergency and daily public safety communications.
FirstNet will build, operate, and maintain the first high-speed, nationwide wireless broadband network dedicated to public safety. This so-called AWS-3 band has become very valuable, because increasing numbers of Americans use Internet-enabled wireless devices to do more things that require faster networks, such as watching streaming video.
This AWS-3 band already had incumbent users, and new users would have to share it. Box D. Furthermore, the licensees will have to wait before they can use their new spectrum because DOD is using some of the frequencies for missile guidance systems, drone training programs, and similar activities. DOD expects these programs to take years to relocate to other spectrum bands.
As noted in Chapter 4 , he Boulder telecommunications laboratories can provide considerable value to operation of this new shared allocation and have the potential to act as an independent agent to resolve disagreements. Auction 97 was authorized to raise money for the federal government, including the funding of FirstNet. The aim of this newly defined band is for all safety officers police and fire fighters to migrate to this new band. Not all bands in this spectrum are equally valuable for all applications.
The lower frequencies can be transmitted through walls and are useful for mobile phones, for example. But they have smaller bandwidth so they cannot carry large amounts of information. They also require larger antennas than do the higher frequencies. Higher carrier frequencies designated with larger bandwidths can carry more information, but walls and other obstacles may block it.
The highest frequencies—millimeter waves mm-band 30 GHz and above —are also attenuated by foliage and absorbed in the atmosphere. The propagation distance through the atmosphere generally decreases as the frequency goes up.
This has advantages because the frequencies can be reused easily with the limited propagation range in this band. Thus, millimeter-waves may be useful for line-of-sight transmission for short distances. While they use smaller antennas, the electrical components become more expensive at higher frequencies. However, the cost per bit of information will decrease. Furthermore, licenses for services at higher frequencies are typically less expensive than at lower frequencies because they are not suitable for mobile phone applications.
Also, mm-wave bands can be made available quickly because there are no incumbent users. All these factors point to an expected increase in mm-wave wireless telecommunications. Typical systems split the carrier frequency into a number of channels, each with a specific transmission bandwidth that determines the rate of information that can be transmitted.
Ten times the frequency can mean either ten times the bandwidth per channel or 10 times the number of channels. As transmission frequencies move into the multi-gigahertz range, larger bandwidth channels are possible, and continuous innovations in technology promise to deliver ever-increasing bandwidths and capabilities.
Incumbency Issues. The AWS-3 bands are currently being used by Federal and non-Federal incumbents for a variety of government and non-government services.
AWS-3 licensees are subject to various requirements related these incumbent users, including Federal and non-Federal relocation, sharing, and cost-sharing obligations, coordination requirements, and protection of Federal and non-Federal incumbent operations. License Period. Initial licenses for AWS-3 spectrum will be granted for a twelve-year term, with subsequent renewal terms of ten years.
Construction Requirements. There are buildout requirements for the AWS-3 licenses offered in Auction An AWS-3 licensee must provide reliable signal coverage and offer service to at least 40 percent of the population in each of its license areas within 6 years after license grant, and provide reliable signal coverage and offer service to at least 75 percent of the population in each of its license areas by the end of the initial twelve-year license term.
Some of the spectrum is set aside for unlicensed applications, meaning one does not need a license to use the spectrum as long as one abides by defined constraints associated with the specific bands. These include the ISM radio bands, reserved internationally for the use of EM energy for industrial, scientific and medical purposes, and the U-NII band, used extensively for wireless local networks.
The ISM band is a part of the radio spectrum that can be used without a license in most countries. Industrial applications. Radio frequency energy is used for a variety of industrial welding, heating, and drying applications, including ceramics, foam, fiberglass, composites, textiles, food tempering and pasteurizing, wood, and paper.
Industrial RF heaters can have powers in the kW range. As just one example, RF energy is useful for sealing plastics. An RF heat sealer heats a plastic part to the point at which it can bond with another plastic part or to another surface.
The technique is faster and cleaner than conventional thermal welding and also produces a stronger bond. There are more than , RF heat sealers in operation in the United States used in a variety of industries. The power generated by an RF heat sealer ranges from about 1.
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The Newnes Know It All Series takes the best of what our authors have written to create hard-working desk references that will be an engineer's first port of call for key information, design techniques and rules of thumb. Guaranteed not to gather dust on a shelf! RF radio frequency and wireless technologies drive communication today. This technology and its applications enable wireless phones, portable device roaming, and short-range industrial and commercial application communication such as the supply chain management wonder, RFID. Up-to-date information regarding software defined RF, using frequencies smarter, and using more of the spectrum, with ultrawideband technology is detailed. Daniel Dobkin has been involved in the development, manufacturing, and marketing of communications devices, components, and systems for over 28 years. He is the author of three books and 30 technical publications, and holds 7 US patents as inventor or co-inventor.
In RF Microelectronics, Second Edition, Behzad Razavi systematically teaches the fundamentals as well as the state-of-the-art developments in the analysis and design of RF circuits and transceivers. Download it once and read it on your Kindle device, PC, phones or tablets. This contributed volume brings together a team of experts to provide state-of-the-art coverage of network theory basics, the design of passive circuits, solid state devices, and. ISBN hardback 1. The Second Edition introduces RF design tools such as the Smith Chart, dual port networks, S-parameters, and provides extensive coverage of RF filter design, matching networks, active and passive device modeling, narrow and broadband amplifiers, mixers, and oscillators. Based on fundamental principles of electrical engineering, the text shows that microwave circuits and devices can be explained through the use of circuit theory, Maxwell.
Jump to navigation. Index click on topic below. Electromagnetic radiation consists of waves of electric and magnetic energy moving together i. Taken together, all forms of electromagnetic energy are referred to as the electromagnetic "spectrum. They are collectively referred to as "radiofrequency" or "RF" energy or radiation. The RF waves emanating from an antenna are generated by the movement of electrical charges in the antenna. Electromagnetic waves can be characterized by a wavelength and a frequency.
RF and Wireless Technologies: Know It All (Newnes Know It All) [Fette, Bruce A., Aiello Ph.D., Roberto, Chandra, Praphul, Dobkin, Daniel M., Bensky, Dan.
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RF Engineering for Wireless Networks, Daniel M. Dobkin
The term wireless communication was introduced in the 19th century and wireless communication technology has developed over the subsequent years. It is one of the most important mediums of transmission of information from one device to another devices. In this technology, the information can be transmitted through the air without requiring any cable or wires or other electronic conductors, by using electromagnetic waves like IR, RF, satellite, etc.
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