In this paper, high performance antennas are proposed for massive deployment of wireless sensor networks (WSN) for early fire dectection in forested areas. A differential slotted microstrip patch antenna and a Quasi-Yagi microstrip antenna are proposed to be implemented in a WSN at 2.4 GHz (ISM band). Firstly, a microstrip Quasi-Yagi antenna has been studied and optimised to operate at 2.4 GHz, which is sough to be deployed as part of a sectorized base-station. The antenna is comprised of one reflector and six directors around a microstrip patch to create an end-fire radiation pattern. According to simulations, the optimised antenna reaches a gain of 9.41 dBi and a half-power beamwidth of 70◦ at 2.44 GHz, with a operating frequency band from 2.27 to 2.83 GHz. For the sensor node, a very small differential slotted microstrip patch antenna is proposed, which has been redesigned and optimised to operate at 2.4 GHz. The proposed design takes advantage of slotted resonant elements in order to reduce the overall size of the antenna. Simulation results ensure a realised gain of 4.15 dBi at 2.44 GHz and an operating frequency band from 2.37 to 2.5 GHz. The results present in this paper were performed by using thesimulation software CST-MWS.