Antenna Systems & Technology - Winter 2013 - (Page 20)

FEATURE ARTICLE Next Generation Wireless: Riding On the Back of Millimeter Waves By Renaissance Electronics and Communications Of all the wavelengths in the spectrum used for wireless data transmission, perhaps the least known is the millimeter wave band. However, it is precisely this band (and the continuous bandwidth it provides) that enables wireless data transmission at speeds and bandwidth that compare to the high quality of fiber optic communication systems. Millimeter waves (30 to 300 GHz) are a subset of the microwave band, which is itself part of the larger radio wave spectrum. These waves derive their name from the size of the wavelength, which measures from one to 10 millimeters. Unlike low frequency radio signals, millimeter waves are not appropriate for long distance transmissions through the atmosphere, due to higher signal loss. Instead, MMW radios typically operate over distances of several kilometers using highly directional, "pencil" thin beams that also help prevent interference. It is this characteristic, along with continuous bandwidth not available at more commonly used lower frequencies that makes millimeter wave technology the ideal solution for point-to-point, high speed, high bandwidth wireless. The technology, available as commercial transmitter/receiver units that operate at Gbps speed, is already being utilized in multi-billion dollar markets such as cellular communications for the next generation of micro and picocell towers, high definition/3D digital video for broadcasting organizations and the motion picture industry, and for high frequency trading on Wall Street. The Millimeter Wave In spite of the relative anonymity of MMW radios in the commercial area, the MMW spectrum has been utilized for military satellite-satellite communications for decades. Due to the dramatically reduced costs recently of MMW integrated circuits (a trend that is expected to continue), the technology is now being increasingly utilized for commercial applications. The incredible promise of the millimeter wave, however, has as much to do with the Federal Communications Commission (FCC) as any other factor. The FCC was formed by the Communications Act of 1934. As part of its mandate, the FCC allocates specific wavelength frequencies for everything from FM/AM radio stations to television, cell phones, satellites, aeronautics, and the military - to name a few. However, with the explosion of wireless applications, most are jammed into small bands at lower frequencies of the radio spectrum. Although the millimeter wave band is also regulated by the FCC, if the more crowded bands can be compared to the population per square foot of Manhattan, New York, then the wide open expanses available to millimeter waves are more like Yellowstone National Park. This extra space is critical because it provides the "continuous bandwidth" required for high bandwidth, high speed data transmission. Without it, lower frequency products (despite being capable of such speeds were it not for its neighbors) are hitting a glass ceiling that even refinements and improvements in wireless technology cannot overcome. Lower frequency allocations, for example, are typically 2 to 5 MHz. In the millimeter wave spectrum the total allocation potential is up to 250 GHz, with 5, 7, 10, 15, even 20 GHz of continuous bandwidth available. With so much room to work with, practical data rates in the millimeter band top out above 40 Gbps. 20 Antenna Systems & Technology Winter 2013 www.AntennasOnline.com http://www.AntennasOnline.com

Table of Contents for the Digital Edition of Antenna Systems & Technology - Winter 2013

Editor’s Choice
LTE's MIMO Requirement Strengthens the Need for Active Antenna Systems
Optimizing Cell and Tower Sites During the Data Explosion
Improve Passive Intermodulation Performance with Specialty High-Frequency Circuit Materials
Next Generation Wireless: Riding on the Back of Millimeter Waves
Antennas
Components/Subsystems
Test & Measurement
Marketplace
Industry News

Antenna Systems & Technology - Winter 2013