I'm using below the outdoor antenna for Huawei E5186 4G Router, very good to recommend!
https://www.4gltemall.com/4g-lte-outdoor-antenna-2-x-sma-connectors.html
http://www.4gltemall.com/media/wysiwyg/18_dBi_High_Gain_Panel_Flat_4G_Outdoor_Antenna_7_.jpg