On Wed, 17 Sep 2003 15:41:33 -0700, Roy Lewallen
wrote:

Well, actually, no. The radiation resistance generally decreases as an
antenna gets smaller, assuming it's small compared to a wavelength.

Roy Lewallen, W7EL


At any given frequency, you can analyze the impedance of a small
antanna as a series R-C or a shunt R-C. Viewed as a shunt resistance,
Rr increases as the antenna gets smaller, and as a series network, it
gets smaller.

I guess the standard convention must be to treat Rr as a series
element, so it gets smaller as the antenna gets smaller.

Either way, it takes more volts (or, if you prefer, more amps) to
force a small antenna to radiate as much as a larger one.

John