For VR/AR service, it is necessary to obtain high throughput in wireless local access network (WLAN). Conventional multi-port antenna is not appropriate for WLAN devices due to space constraints of the WLAN device. Meanwhile, it is possible to obtain multiplexing gain by achieving pattern gain. However, previous antennas with pattern gain have not been designed for the WLAN devices. In this paper, we designed a compact 4-port antenna for the WLAN device, which is 0.5 times smaller than the conventional antenna. We also show that the proposed antenna obtains close multiplexing gain compared to ideal antenna in poor channel cases.