In this paper, a lunar waning crescent Quasi-Yagi microstrip antenna is presented. With the aim of being employed in a multi-sector base-station (BS) antenna of Wireless Sensing Network (WSN), the antenna is designed and optimised to operate in the 2.4 GHz ISM band. Specific project requirements, such as: resonating frequency, gain, half power beam-width (HPBW) and, consequently, Field of View (FOV) are taken into consideration when dimensioning the antenna. After proper design optimization, carried out with the aid of a full wave electromagnetic solver (CST Microwave Studio), a six equal directors and one reflector antenna yields 9.7 dBi of realized gain, a HPBW of 60◦ and a back-to-front ratio of 18.63 dB, at a resonating frequency of 2.44 GHz.