timmac wrote:
What is a Digital TV Antenna?
A digital TV antenna is a television antenna that allows you to receive digital signals over the air. It is similar to an analog antenna because it interprets signals it receives in order to provide you with television entertainment and media. However, digital signals generally provide a clearer picture, and television is no longer sent over analog signals.
Nope - the antenna does NOT interpret anything - it receives the incoming signal and sends it to the receiver. The antenna is a completely passive device - basically a piece of wire that reacts to RF vibrations in the air, by vibrating at the same frequency as those vibrations. That sympathetic vibration is then sent through a wire to the input of the receiver, where it is "interpreted", and transformed into light and sound waves that we experience.
A traditional analog antenna, or "rabbit ears" as they were sometimes called, used to pick up analog RF signals in the air. The antenna could receive the information and display television programming. Digital antennas serve essentially the same function, but the information they are receiving is transmitted digitally, and not with analog RF signals.
Rabbit ears are simply a type of antenna - there are other types ranging from a simple wire to a yagi explicitly cut to a length equal to the wavelength of a specific signal. Rabbit ears were a compromise to allow the user to easily adjust their aim to receive a slightly stronger signal. Rooftop antennas are modified yagis - they have different elements cut to different lengths so they can effectively receive several wavelengths - the user can adjust their aim by using an antenna rotator. Those rabbit ears, or ANY antennas, do not "display" anything - they merely transfer the signal from the air to the receiver. The rabbit ears you bought back in the 1950s will still work today. They don't care what kind of information is included in the signal - they simply pass it along to the receiver.
A digital TV antenna can be attached directly to your TV. It has to be able to pick up a digital signal, however, so a signal has to be available from a satellite or from another source of digital programming such as a local broadcast station. It can also be attached to the roof of a home where it has access to a digital signal.
The antenna does not care what is contained in the signal - that's the job of the receiver. The antenna sees the carrier signal and passes it on. Whatever is encoded on that carrier signal gets passed along with it. A single antenna will receive signals from TV stations, radio stations, CB radios, VHF radios, wi-fi routers - basically anything that is emitting an RF signal in the vicinity, and pass it along to a receiver, which will select the signal that it was designed to recognize.
In order to transmit the television programming to a TV, the TV must be able to decode the digital signals it receives from the digital TV antenna. All televisions produced and sold after February of 2009 have the ability to decode digital signals built in. Televisions produced prior to 2009 may or may not be able to receive signals from a digital tv antenna, depending on whether the television has a digital converter or not.
You're placing way too much intelligence to that piece of wire called an antenna - it will pass on whatever signal it sees, regardless of what's encoded in the signal, and regardless of the capabilities of the receiver to understand it. It's the receiver that will see the signal, and if the signal is recognized as something that it was designed to interpret then that signal gets processed. It's no different that a radio antenna: another piece of wire that receives RF signals - it doesn't know whether it's connected to an AM radio, an FM radio - it simply passes the signal to the radio, which is designed to process AM or FM signals, and ignores whatever signals that don't match what it was designed to process.
