Pires, NunoParra, TiagoSkrivervik, AnjaMoreira, Antonio A.2017-09-052017-09-052017-09-05201710.1109/Lawp.2017.2708742https://infoscience.epfl.ch/handle/20.500.14299/140351WOS:000407360900088This letter presents the design and measurement of an antenna integrated into an agricultural sensor network node operating on the 2.4-GHz ISM band using the ZigBee protocol stack. The novel structure, coined bowtie-shaped folded dipole (BSFD), has a differential 100-Omega input impedance matching a particular controller widely used in wireless sensor network (WSN) applications. This letter also presents a survey of existing WSN antennas to which the proposed design compares favorably. The challenges of testing a differential antenna using conventional single-ended equipment are addressed regarding antenna impedance and radiation pattern measurements. The differential antenna input impedance was confirmed with four different test setups using a conventional vector network analyzer. The radiation pattern of the proposed antenna was measured in-prototype resorting to a spectrum analyzer. The measured patterns show that the proposed antenna has a maximum received power over 4 dB compared to two early versions of the WSN node that used commercial off-the-shelf antenna solutions. The performance was also confirmed in a field test where a BSFD-equipped prototype achieved close to a 300-m range, tripling that typical for ZigBee applications.Antenna measurementsdifferential antennawireless sensor network (WSN)WSN antenna surveytext::journal::journal article::research article