ARIB 8494B, Руководство пользователя, Страница: 35 / 39

ARIB STD-T91
-29-
(3) Measurement of characteristics of an antenna
Connect a signal source and a measured antenna as well as a measurement device and
a standard antenna as shown in Figure A3-6 in an environment such as a radio anechoic
chamber, and measure the absolute gain of the antenna. The absolute gain of the
antenna is likely to be a negative value in most cases because the frequency in the
interference band deviates from the frequency used for UWB radio system.
Absolute gain of an antenna Ga [dBi] is obtained as a measured result.
Figure A3-6 A connection example for characteristics measurement of an antenna
(4) Estimates of unwanted emission intensity
It can be estimated that the unwanted emission intensity is
 -Lf+Ga [dBm / MHz e.i.r.p.] .
(5) Design of UWB radio equipment
Based on the unwanted emission intensity estimated by (1) - (4), it is possible to design
UWB radio equipment to meet the conditions of Table A3-1.
2 Ban on the use of UWB Radio Equipment for Toys
UWB radio equipment shall not be included in toys. This is because a child may not be able to
properly restrict the UWB radio system usage outdoors, in airplane, or at an event site, etc. The
terminology of toy is not strictly defined in this Annex, but manufacturers, etc. of UWB radio
equipment should properly judge by themselves with due consideration of the intent of this
standard.
In this regard, toys which do not permit embedded UWB radio equipment shall include but
not be limited to game machines that run without AC mains power supply.
Measurement
device
Measured
antenna
Standard
antenna