Theoretically, non-directional radiation pattern is known as isotropic radiation pattern; but,
isotropic antennas are practically not available.
The SU-Tx is equipped with an ESPAR antenna, and transmits symbols to the SU-Rx, which is equipped with an
isotropic antenna, while jointly keeping interference to N PU-Rxs (equipped with
isotropic antennas) under a certain limit.
Anritsu Company said it has expanded its electromagnetic field (EMF) measurement system with the introduction of
isotropic antennas that provide frequency coverage from nine kHz to six GHz.
Consider a linear uniform adaptive array with M
isotropic antennas separated by a distance d between neighbors, k + 1 independent transmitted signals impinge the array from directions [[theta].sub.0], [[theta].sub.1], [[theta].sub.2], ..., [[theta].sub.k], with the broadside direction.
where [[parallel] x [parallel].sub.F] is the Frobenius norm, [n.sub.R] the number of receiving antennas, and [H.sub.ref] the channel matrix with the two
isotropic antennas at the BS and the '2-ISO' at the MS, respectively.
[L.sub.s] = the spreading loss in dB between
isotropic antennas[13] employed a modified PSO algorithm for thinning large multiple concentric circular ring arrays of uniformly excited
isotropic antennas to generate a pencil beam in the vertical plane with minimum relative side lobe level.
The proposed method has been applied to generate two different beam pairs from a single concentric ring array of
isotropic antennas. Two different cases comprising a pencil/pencil beam pair and a pencil/flat-top beam pair have been considered.
However, by assuming
isotropic antennas, we get range and frequency terms in the RF equation.
The above definition characterizes the communication link performance of two antennas as compared to two ideal multi-element
isotropic antennas that pick up all the available multi-pole channel power, i.e., the total available link power.
Where: G is the ratio of the signal leaving the target to the signal arriving at the target (both referenced to
isotropic antennas) (in dB)
One other point about spreading loss: The loss value derived from the nomograph and from the above formula is for the spreading loss between two
isotropic antennas (that is, antennas with "unity" or 0-dB gain).
