Abstract:
The IoT applications like smart warehouse, smart
industry, and smart vertical farming will require microwave
power transmission (MPT) to the densely deployed low power
sensor nodes in three dimensional (3-D) space. To address this
issue, a switched beam array antenna is synthesized as an MPT
system to power the proposed 3-D clustered wireless sensor
network (WSN). The 3-D space is divided into nine clusters, each
illuminated individually with RF power using a dedicated patch
antenna subarray. The subarrays can be switched on or off based
on the energy requirement of the WSN cluster nodes resulting
in efficient power transmission. Moreover, the low complexity of
switched beam design reduces the cost and processing overhead
as compared to the exiting adaptive beamforming systems in a
dense WSN scenario. The subarray size and excitation coefficients
are optimized with a constraint over the harvested DC power
(Pdc) to enhance the 3-D coverage. In addition, the optimal
location of the cluster head is evaluated to minimize the average
power consumption of WSN cluster. The subarrays are designed
and fabricated with the evaluated excitation coefficients, and Pdc
measurements are carried out validating analytical results.
