A hybrid dual-band power amplifier (PA) prototype working at two Industrial, Scientific and Medical (ISM) bands, 2.4-2.5 GHz and 5.725-5.875 GHz, was designed for Unmanned Aerial Vehicles (UAVs) communication applications in Spain. Initially, two single-band PA prototypes centered at each band were designed to evaluate the single-band achievable RF performance. In all the PAs, the Gallium Nitride (GaN) Qorvo HEMT TGF2977-SM was used, as well as microstrip transmission lines technology. To achieve wideband, good linearity and efficiency, the PAs were designed in class J. The measured results for the dual-band PA prototype at the 2dB compression point at the lower and higher bands, respectively, are 14.8 dB and 11.2 dB of Transducer Power Gain (GT ), 35.7 dBm and 34.8 dBm of RF output power (Pout) and 59.2% and 43.5% of Drain Efficiency (η). At 3dB compression the respective lower and higher bands results are 37.9 dBm and 37 dBm of Pout and 73.9% and 55% of η.