Radiowaves are the oscillations of magnetic waves by varying the modulation to generate different signals which can be converted into information such as sound, video, or digital communication. As these waves pass through a conductor, an alternating current is generated and this can be converted into usable information.
As one could see from the picture above, radio waves are the the electromagnetic waves with wave lengthes between 1mm and 10 Mm. This converts to a frequency range of 300Ghz to 30Hz, respectively.
Nearly everyone uses radio waves in some form day after day. The technologies that depend on them is vast and ever-growing. These technologies range from cordless phones and garage door openers to radar and microwave ovens. Radio is not a dead technology either. It is constantly having research devoted to it and new technologies and innovations are coming about from this research. The trend towards wireless internet and more versatile cellular phones are just some examples. Ironically, the fundamentals of radio waves is relatively simple (atleast when compared to the vast array of technologies that now implement it).
Cordless phones use radio waves to allow individuals to walk around freely in their home without the need to be bound by a cord while talking over their land-based phone line.
Cell phones are a miracle to modern day living. Unlike previous eras where communication was done strictly across a hard-wired telephone line, cell phones now give the freedom to those that can afford them a radio-based uplink to the rest of the world. Not only are they for voice communication, but they also allow for transmission of virtually any kind of digital data.
Microwave ovens are another great invention from the 20th century. They use radio waves in a specific frequency range in which water, fat, and sugar molecules happen to absorb and convert directly into heat.
Radio waves were first discovered in 1887, but radio itself was initially invented by Italian Guglielmo Marconi in 1895 (1). His biggest mentioned success was in 1901, when he managed to broadcast the letter “S” across the Atlantic Ocean (1). However, he focused primarily on point-to-point transmissions, not large scale broadcasts from one point (F). As such, three American inventors - Lee De Forest, Edwin Howard Armstrong, and David Sarnoff - took credit for making radio as it is today a success (F). De Forest was born and raised in Alabama and he thought of everything in terms of patents and eventually held more than 300, but many claimed that he simply stole the inventions of others (2). In 1900, he patented a device to enhance weak signals and in 1902, he formed the De Forest Wireless Telegraph Company (1). In the same year. Reginald Fessenden, a Canadian, invented the “electrolytic detector”, which later became the spade detector that brought De Forest so much fame (F). In 1904, John Fleming invented the oscillation valve, which later became De Forest’s audion, and De Forest won the gold medal at the St. Louis World’s Fair for his “spade detector” (F). De Forest gained quite a bit of fame by broadcasting music live from the Eiffel Tower and from the Metropolitan Opera; however, many believed that this was a scam and that he had actually had the device broadcasting the signal only a few blocks away (F). In 1906, he envisioned bringing music and voices to all American households, but as it turns out Canadian inventor Fessenden had already broadcasted a Christmas greeting and music to the crew of a ship off the coast of Canada on Christmas Eve a year earlier (F). In 1912, Armstrong became prominent by inventing regeneration, wh...
Most radio historians assert that radio broadcasting began in 1920 with the historic broadcast of KDKA. During the 1920s radio benefited Americans because it was a source of their entertainment, the music industry of jazz, and advertisements.
Over the years, many people all over have listened to the radio for entertainment and information. Radio supplies news, sports, music, talk, and many other options with great ease. However, since television has become so popular lately, people look to it as an alternative to radio for the previously stated options. The reason for this can be linked to the redundancy that radio has encountered by not offering anything new and exciting for people to become interested about. Now, XM radio has solved this problem by giving people something new to look forward to by offering their services to anyone who wants to try something new. XM Radio uses satellites positioned in space to allow people to listen to the radio across the United States without having to be bothered with changing stations. This luxury has gotten consumers and analysts very excited and has been receiving a lot of hype in the media lately. The advanced methods of broadcasting will supply XM Radio with more appealing features to listeners than existing entertainment. As a result, those who are bored with the current condition of radio entertainment may use XM more than FM and AM radio.
Just whip out your handy dandy cellular device and now you don’t have to talk to anyone! Cell phones are perfect for avoiding those awkward conversations, weird situations, they can even find you a spouse while at the same time help our population decrease, creating more jobs and space in the world! Everyone gets stuck in situations where they feel awkward; whether it’s on a bus, in the mall, walking down the street, or even driving; a cell phone is the only solution to solving these problems. Cell phones make it easy to block out the world surrounding you.
When cell phones were first introduced, all you could do was call others and talk for half an hour. It was like a brick and took ten hours to charge. It also cost $3995. That’s a lot more than most of today’s cell phones. Even, though it was a very basic phone, it began impacting the world. Now, you could call your relatives and actually talk with them without being next to them. Parents gave their kids cell phones to stay in touch. Now you can contact anyone through your mobile phone in multiple ways. You can text, call, facetime or message someone through social media. Cell phones abilities
Cellular phones are a phenomenon that has engulfed people in the nineties. They have become a common occurrence whether you are waiting in line at the super market or in a movie theatre. One professor at Murray State University said, “Many students are carrying them, I had a student get a call in the middle of a test last semester.” Although many people have accepted the thought of carrying a telephone wherever they go, others have not taken the onslaught of cell phones quite so easily. Cell phones have become part of everyday life, and with the dramatic changes that have been made, there is no sign of their existence diminishing. Today, cellular service is available in all 306 Metropolitan Statistical Areas across the country and all of the 428 Rural Service Areas.
Cellphones have changed physically and technologically throughout the decades. From the militarized phone bags that were used to give orders during war to the more modernized, smaller, multi-use cellphones where anything can be found
AM radio works by changing the amplitude of the carrier wave and FM radio works by changing the frequency of the carrier wave.
With Television being the dominate medium, and Computers taking second position, where does that leave Radio? 95 years ago radio was the second language of mass media and it has been around since, making it a great survivor medium. Radio has changed the way we communicate. The first broadcast was in 1916 out of the garage of Frank Conrad who moved his station to Westinghouse factory where he relaunched the station as KDKA on November 2, 19201. Radio has since branched out with each branch growing a new form of media to create a world of new Radio sub-categories. Radio has become a medium of entertainment, education and information giving listeners a form of imagination, relaxation and escape from our daily lives.
The radio is a wireless form of communication which is transmitted through sounds or signals by electromagnetic waves directly through space to a receiving set. Some types of radio communications are HAM radios, CB (Citizen Band) radios, Cell Phones, Radio Scanners and Walkie-talkies. Radio communications are widely used in the United States and majority of it is used by law enforcement and emergency services. Police/Sheriff, Fire-Rescue, Highway Patrol, Ambulance and EMS are some of the agencies that use radio communications.
By the time the 20th century arrived, vacuum tubes were invented that could transmit weak electrical signals which led to the formation of electromagnetic waves that led to the invention of the radio broadcast system (750). These vacuum tubes were discovered to be able to transmit currents through solid material, which led to the creation of transistors in the 1960’s (750).
Radar is usually taken for granted in these days of modern technology. Many people do not know how radar is really used, how it works, or why we need it. People are familiar with several uses of radar like police enforcement radar guns and radar that measures how fast a baseball is pitched in a major league game. These are only a few of the many uses radar has to offer. Radar can determine several properties of an object from a distance, such as its position, speed, direction of travel, and shape; it can also detect objects out of the range of sight in all weather conditions, making it a fundamental utility for many industries.
waves are further divided into two groups or bands such as very low frequency (
Cell phones represent a type of technology that has been around for more than over fifty years; it has only been recently that many people began to use cell phones as a major part of their everyday life. In the past cell phones were for business people to conduct their business, but in today’s society every one owns a cell phone. Cell phones are interesting, useful and also play a major role in our life’s bringing people closer and keeping in touch with one another. Most people do not know and understand the physics of a cell phone. Cell phones are also known as cellular phone, hand phone, and commonly known as a mobile phone. A cell phone is an electric device that can make and receive calls, over and automatic repeat request (radio link petrol -RLP) used over wireless air interdace.it us a portable telephone that uses and receive phone signals.it also divides that earth into small regional called cells.in the resent estimates there are over 190 million people using mobile phone. One of the primary health concerns is the impact of cell phone radiation, by radio waves by which it operates.
Radio broadcasting was introduced to the public in the early 1920s (Potter 226). There was only one type of broadcast protocol in the 1920’s and 30’s being AM radio(The Early Years). In 1921 there were only five AM radio stations, and only about 1% of all households in this country had a receiver (Potter 226). A receiver was basically another name for a radio because at this time radios were very expensive and there were not enough radio stations to make the system work. However, in 1923 there were over 500 stations to pop up which in turn led to increased sales of receivers to the general public (Potter 226). With the popping up of more radio stations the more receivers were being bought which meant that many people in the public were tuning into these various radio stations for information and entertainment. Radio was on the rise and it seemed that there was nothing slowing it down.