The amount of wireless of connectivity, and the options to do so, are abundant in today’s electronic gadgets. WiFi, Bluetooth, UHF and 4G are just a few of the connect options available to the global consumer. All of this wireless connectivity can all be traced back to a significant invention called “The Radio”.
Radio is made possible by the transmission and reception of Microwave Signals. Using modulation, audio, video and/or information, can be transmitted and received over many miles, via Radio Frequency (RF) Microwaves. One of the first incantations of the radio was developed by Guglielmo Marconi. Born in Italy, his experimentation was centered around the microwaves generated, during the creation of high voltage sparks. After some trial and error, followed by refinement, he came up with the now famous “Spark Gap Radio”, witch led to most of the radio technology we enjoy today. It was later said that Marconi may have lifted some of the ideas contained within the patents held by Nikola Tesla, whom was the father of high voltage phenomenon.
The video shown above, originally broadcast by the BBC, is a documentary showcasing the evolution of Radio Technology, titled “The Secret Life of The Radio“. The informative science documentary TV series, was also carried by the Discovery Channel. Produced by the “The Secret Life Of Machines” written by Tim Hunkin, and presented by Tim Hunkin and Rex Garrod. There would be many who’s contribution to the refinement of “The Radio” would be instrumental, including individuals like Nikola Tesla, Howard Armstrong, Heinrich Hertz and companies like RCA. The cover image is of the “Marconi Titanic Radio Apparatus”.
Microwave science has reached a point far beyond the early days. The basic principals still apply, however their application has been refined across today’s technology. Our cities are saturated with RF Signals from GPS, Satellites, Radio Stations, Radar, Broadcast, WiFi, Cell Phone Communications, DOD, Mobile Radio and the like. Since the 1970’s organizations like the FCC (Federal Communication Commission) and the NTIA (National Telecommunications and Information Administration), have been responsible for making sure that all these RF Signals do not interfere with each other. This is done by allocating Frequency Bands of operation for various types of usage. See “US Frequency Allocations” via NTIA for details.
The grey faced rack mount radio above is an early Radio Receiver developed by Marconi Instruments. The initial prototype was designated CR100. This was followed by variants designated CR100/1 through CR100/8. None of the CR100’s were ever fitted with S-meters as standard. The CR100/2 was also called the R.A.F. type R1297 receiver, as it was issued to the Royal Air Force and the other services, except the Navy.
Around the 1980’s new possessor speeds and data-rates, within IT equipment, caused the generation of “non-intentional” RF Signals, potentially interfering with bands allocated for broadcast and communication. The FCC responded by inn-acting new rules effecting the design of digital equipment. Resulting in what we know today as the Class-B (for consumer) and Class-A (for commercial) regulatory emissions standards.
Between the 1980’s and 2000, most of the engineering community has embraced the regulations, resulting in most products today operating with minimum RF Signal generation. Since 2010 most of the FCC’s resources are focused on Radio Technology used for wireless connectivity, as found in the 802.11 specification.
In 2015 wireless communication frequencies can be found up to 300 GHz. In the next 10 years, can we expect them to increase? What is the physical limitation to engineering components and systems that can operate at frequencies in excess of 500 GHz? The image above is of a “Radio Communication Test Set” developed by Marconi Instruments. Who will be the next Nikola Tesla, Guglielmo Marconi? Who will take Radio Frequency technology to the next level? Only time will tell.
Article: HCT America
Editor: M. Danmole’