Searching for primordial gravitational waves in the cosmic microwave background (CMB) polarization signal is one of the key topics in modern cosmology. Cutting-edge CMB telescopes require thousands of pixels to maximize mapping speed. Using a modular design, the telescope focal plane is simplified to several detector modules. Each module has hundreds of pixels including antenna arrays, detector arrays, and readout arrays. The antenna arrays, as the beam defining component, determine the overall optical response of the detector module. In this article,we present the developments of 6 inch broadband antenna arrays from 80 to 170 GHz for the future IHEP focal plane module. The arrays are fabricated from 42 6 inch silicon wafers including 456 antennas,7% more pixels than the usual design. The overall in-band cross polarization is smaller than −20 dB and the in-band beam asymmetry is smaller than 10%,fulfilling the requirements for primordial gravitational wave search.