Design of 200W Ku band GaN HEMT power amplifier is presented. A balanced configuration using 20 mm bare die packaged GaN HEMTdevice is discussed. Branch line coupler is used to parallel cascade two single stage power amplifiers. Inductor based equivalent bondwire array modelis used for this design. Simulated performance of power amplifier (PA) shows 200W output power with drain efficiency of 68% and power addedefficiency (PAE) of 53% at design frequency of 11.10 GHz. Less than 0.5 dB variation in large signal gain is observed between 11.07-11.20 GHz band offrequency. Proposed GaN HEMT power amplifier can be used to replace conventional travelling wave tube amplifiers (TWTAs) used in Ku-band satellitecommunication.