A radio over fiber is one solution to broaden RF signal, a combination between wireless and wireline. An effective conversion between both signals is another way to enhanced this technology toward 5G. A compact design of integrated antenna and electro optic modulation can have dual functions, an antenna and an electro optic modulation. It uses several optical materials to give electro optic effect. The simulation uses a gold patch antenna and copper ground design as the integrated device. This paper purpose a 4 GHz bowtie antenna integrated with optical modulator. The integration is designed by inserting an optical material in a gap between two arms of bowtie antenna. It has optical crystals layer as a modified bowtie antenna to enlarge the electrical field on the antenna. The electrical field is compared and analyzed using a formula based on the simulation results. The impact of impedance mismatch in the integrated antenna gives a minimized formula that can give one and 2.7 times better electrical field for electro optic alteration. The simulation gives better bandwidth 115,83% but smaller gain 73.3 % than the conventional.