"Ian Jackson" napisal w wiadomosci
...
In message , Szczepan Bialek
writes



"The wire antennas used with crystal receivers are monopole antennas

The words "almost always, almost every time, almost invariably and almost
without exception" are missing.

As crystal receivers are normally used at low frequencies (long and medium
wave), the obvious antenna to use is an end-fed long wire monopole. This,
of course, requires a ground.

However, in principle, you could use a (probably large) dipole, provided
you modified/designed the circuit of the receiver so that it would take a
balanced input (which would probably also be low impedance).

I'm pretty sure that some of the early radar receiving systems used
essentially a dipole antenna feeding a crystal receiver.

You are right:
"A simple rectenna element consists of a dipole antenna with a diode
connected across the dipole elements." And:
"A nantenna is a very small rectenna the size of a light wave, fabricated
using nanotechnology, which acts as an "antenna" for light,"

Each rectenna arm (or dipole element) must be shorter then 1/4 WL.

But: "Where the electrons come from?
S*