yes they are available
Depends on what you mean by high frequency. The rabbit ears antenna used in broadcast TV is a dipole and is used for VHF.
If it is widescreen and has an antenna (RF) input.
Any station that is close enough to your antenna and the TV has the proper tuner for the available stations. Pointing to the correct direction for the transmitting towers and then rescanning the TV is very important.
HDTV, High Definition Source (HD Cable Box, Antenna, HD Satellite Box), the cables to connect them.
I would suggest eBay for a high definition antenna. or other websites like gum tree and Craig's list. why would you pay the expensive prices at a department store.
High definition camcorders are available at almost all electronics stores, such as future shop and best buy. The are also available online on the manufacturers' sites as well as other sites like ebay.
depend on how high your antenna
http://www.amazon.com/Cisco-Linksys-High-Antenna-Connectors-HGA7T/dp/B0002F3G7M is a great place to get the latest high gain antenna with great prices.
The Sky Box is just one way to enjoy High Definition television. There are a few other services that can broadcast High Definition Television to your home. It may depend on what services are available in your area.
You can still receive TV signals by antenna, but the signals can only be read by high definition receivers. "New" TVs, VCRs, Satellite boxes and Cable boxes will be labeled as HD ready, so they can translate high definition transmissions, but older, analog based TVs and VCRs will require an adaptor to translate the HD signal. From what I understand, adaptors will soon be available for about $70 to $80 each and there are supposed to be coupons or vouchers available that will offer a $40 discount (one coupon per family) to the general public.
Antennas are designed to work in certain frequency bands. They are essentially "tuned" to one or more bands (Depending on elements used) to increase the gain in those bands. Now if the signal is strong enough from all channels you can get by with just connecting a wire to the antenna input. The length of the wire in terms of the wavelengths of the signals being received determines how well the antenna matches to the incoming signal. So the answer is try using your old antenna and if you have signal strength problems you can rotate the antenna or get one specifically designed for your HD channels. Another option is to use an amplifier at the antenna to boost signal going to the TV. If you are close enough to the broadcasting station, you can use a coat-hanger, so NO it doesn't require a special antenna to receive the digital high definition signal locally.
A high-gain antenna is an antenna which allows for precise targeting of radio signals due to it's use of a narrow radio wave beam. To use a high-gain antenna you should put attach it to a high, clear surface to allow it maximum range to receive and send radio signals. A good place would be the roof of your house.