An antenna module having a side-edge balance-to-unbalance (BALUN). The antenna module may include a flexible substrate with one or more layers that may be configured to receive one first and second conductive patterns, the substrate may have opposed first and second ends which may define a longitudinal length and/or opposed side edges situated between the first and second ends. The first conductive pattern may form an antenna loop situated adjacent to the first end of the flexible substrate and be suitable for transmitting or receiving signals at one or more frequencies. The second conductive pattern may form at least part of the BALUN and may include one or more of a center portion, side portions which may extend from the center portion at opposite sides of the center portion, and electrically neutral slots situated between a corresponding side portion and the center portion.