Based on this field, we can estimate the maximum reading distance for RFID tags, and with this we can demonstrate the antenna efficiency
. The value of 94 dBuA/m or 0.05 A/m for the magnetic field is required to activate a standard HF RFID tag and is also the reference value to determine the antenna reading distance in this paper.
The antenna efficiency
over the operating bandwidth of type1 is more useful for handheld mobile devices.
Special attention was given to design of top-hat loading and antenna decoupling structure, thus a broad impedance bandwidth and high antenna efficiency
The frequency bandwidth and antenna efficiency
of the pixelated dipole antenna are compared to those of a planar copper dipole antenna (Table 2).
This means that a good impedance match can be designed directly into the antenna, and a high antenna efficiency
can be achieved.
Cavendish SmarTuners enable capacitive aperture tuning, increasing antenna efficiency
, enhancing reception, and saving power.
c) Antenna efficiency
: It is a ratio of total power radiated by an antenna to the input power of an antenna.
Nonetheless, the antenna efficiency
is less than 80% for the operating bands.
To this aim, to assess the overall antenna efficiency
a figure of merit FoM is often defined in terms of half-power beam width, fractional bandwidth, and peak gain [12, 36].