10 Mar '08 17:53>
How the hell can someone make mobile phone antennas so small, when they work at around 2 Ghz frequencies?
(no super-natural explanations, please) π
(no super-natural explanations, please) π
Originally posted by serigadoThey have resonators that cut down the size. I am a ham operator, so I can give you an analogy to a low frequency dipole: At about 7 Mhz, the "40 meter" ham band, a dipole is about 67 feet long, cut in the center where the feedline goes. If you want to shorten it, you add inductance say, about halfway, depending on how much you shorten it, you might get away with something like 30-35 feet long. The problem with that scheme is the transmit efficiency goes down, you pay for it with a somewhat smaller transmitted signal, even though you might have a decent VSWR (Voltage Standing Wave Ration).
How the hell can someone make mobile phone antennas so small, when they work at around 2 Ghz frequencies?
(no super-natural explanations, please) π
Originally posted by menace71A California dude. Same as me, I started out as KN6QDT then K6QDT when I advanced out of novice. What part of Calif. was he from?
My Dad was a Ham radio operator. I remember he had to match his transmitter to his antenna when he turned his Unit on. One time he forgot to do just that and smoked his transmitter. I don't much about it all but I remember that much. I remember him saying that antennas were a science unto themselves. He made the antenna in our backyard. WA6ANR was his call sign.
Manny
Originally posted by nmdavidbThat depends on how you want to play the game. There are several varieties of amateur radio, entry level to the top level called Amateur extra. The entry level of novice allows you to talk on some bands while more advanced licenses give you more places on the radio dial to talk and other forms like digital mods. Here is a link to the bands allowed and the level of license it takes to get those bands.
Guys...since I have been working on my degree to quit doing stand up in clubs and get on the radio I have always been fascinated with messing around with the whole HAM radio deal.
Can anyone tell me what would be a good set up and the price range?
Oh and trust me I know all about the FCC and all...i do a clean act...which is why most of my gigs lately have been all corporate.
Dave
Originally posted by serigadoOne more quick note about those antennas. At a frequency of 300 megahertz, the wavelength is one meter and a dipole for that wavelegth would be half that, being made up of two quarter wave sections, so a dipole at 300 megs would be about 20 inches, 2 ten inch section of equal length with the feed at the center. Now at 3 Ghz, the wavelength is one tenth of a meter or about 4 inches or 100 millimeters. So a dipole at that frequency is going to be only about 50 millimeters or 2 inches so its naturally small at those frequencies, so at 2 gigs, a dipole would still be only about 3 inches long or 75 mm. So taking a 2 gig antenna and cutting the size in half isn't a huge stretch over a plain dipole.
How the hell can someone make mobile phone antennas so small, when they work at around 2 Ghz frequencies?
(no super-natural explanations, please) π