Under these conditions, the graphite cavities located on the third row all appeared to contain isotropic radiation closely manifesting their equilibrium temperature.
While the 1 1/4" aluminum (top row, left most) and copper (bottom row, left most) cavities appeared to contain isotropic radiation, the brass cavity of the same depth (second row, left most) clearly did not.
Theoretically, non-directional radiation pattern is known as isotropic radiation
pattern; but, isotropic antennas are practically not available.
The designed antenna was half the size of the known antenna, but it had an isotropic radiation
pattern as good as and with the same electrical characteristics as the known one and recognized passive tags over a wide range.
The effective isotropic radiation
power (EIRP) emitted by a reader is set to 4W at 915 MHz.
An MA system with an isotropic radiation pattern receives incoming signals from all directions.
Combining several antennas that have a localized chassis current distribution is shown to be one of the promising approaches to realize an almost isotropic radiation pattern.
Optical properties for diffuse radiation for the glass can be determined for isotropic radiation
by integration over all angles of incidence.
For isotropic radiation
pattern [w.sub.n] in (1) is replaced by Bayliss taper for -30 dB SLL and [bar.n] = 3.
Since (4) is normalized with respect to the antenna gain of ideal isotropic radiation
, it can be larger than one, as observed in Figure 10 .
This idea can be further extended to cylindrical coordination or a 3D case, generating a perfect isotropic radiation
or a single plane wave beam spatially.
However, these antennas have many design parameters that could be optimized to reduce their size and cost, increase their bandwidth, make them sensitive to both vertically and horizontally polarized waves, improve their isotropic radiation
characteristics and reduce their interaction with the human body.