The development of information and communication technology is a challenge to provide good communication in archipelago countries such as Indonesia. VSAT Ku-Band is one of the technologies that have a smaller size, and affordable price compared to the C-Band VSAT with a smaller receiver power and larger capacity. Ku-Band VSAT has a weakness where it is very vulnerable to weather disturbances, especially rain and weak signals in a boundary area. Therefore, a higher antenna gain is required in this research. To achieve high gain, we propose a corrugated horn antenna with combination of a wire medium placed inside the antenna as a parabolic feeder at Ku-Band channels for VSAT application. We use CST Microwave Studio to simulate and optimize the proposed design. The proposed corrugated horn antenna shows bandwidth of 10.3 GHz to 15 GHz, gain of 18.6 dB at transmitter frequency of 14 GHz and gain of 18.5 dB at receiver frequency 12.75. Furthermore, the feeder horn antenna is combined with a parabolic reflector, this design combination has achieved working frequency 10.7-14.5 GHz with linear polarization, gain at receiver and transmitter working frequency are 38 dBi and 42 dBi, respectively.