ZigBee Wireless Soil Moisture Sensor Design for Vineyard ...

It is important to select the appropriate antenna for the hardware design, in
order to save money and increase the operating range. There are three main
solutions, which can be used at 2.4GHz range with the CC2430
microcontroller. The three options are the PCB antenna, Chip antenna and
Whip antenna [38] (refer to Figure 29).
Figure 29: Different Antenna Solutions [38]
The chip antenna is small in size, and development time of the hardware is
short, but the downside is these antennas have medium range performance and
medium cost. The whip antenna has a higher cost compared to the chip
antenna, but it has a very good performance range. The other major issue with
the whip antenna is that it is usually difficult to fit into many applications.
Finally the PCB antenna has very low cost, good performance, smaller size at
high frequencies and the standard design antennas widely available are not
patent protected [38]. Therefore it was decided to use the PCB antenna, in
order to reduce the cost and increase the operating range.
Three PCB antenna options were considered: 2.4GHz TI small size antenna,
2.4 GHz inverted “F” antenna and Folded Dipole antenna. It was decided to
use the Folded Dipole antenna (refer to Figure 30). This is because it has a
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