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 (G T ), 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.