The disclosure relates to a 5th generation (5G) or 6th generation (6G) communication system for supporting a higher data transfer rate beyond 4th generation (4G) communication such as long-term evolution (LTE). An antenna module is provided. The antenna module includes a communication circuit, an antenna unit comprising multiple antenna elements constituting a subarray, and a network unit disposed beneath the antenna unit in multiple layers, the network unit comprising at least one transmission line configured to be branched to positions of the multiple antenna elements, a via hole extending through the multi-layer, and a stub structure disposed on an area adjacent to the via hole. The open stub structure designed on a first layer forming a ground plane, among the multiple layers, may include a first via pad disposed to be adjacent to the via hole, a first open stub extending from the first via pad in a first direction, and a first slot part configured to surround the first via pad and the first open stub. The short stub structure designed on a second layer different from the first layer having the open stub structure designed thereon may include a second via pad disposed to be adjacent to the via hole, a short stub extending from the second via pad in a second direction perpendicular to the first direction, a transformer extending from the second via pad in a third direction different from the second direction so as to be connected to the at least one transmission line, and a second slot part configured to surround at least a portion of an edge of the second via pad, the short stub, and the transformer.