In this article, a new structure for balanced directional couplers (BDCs) in single-layer technology is presented for the first time. An innovative combination of single-section coupled lines, microstrip to coplanar waveguide (CPW) crossovers, and 180° transmission lines (TLs) as an alternative for baluns are used to create the single-layer balanced structure. Furthermore, the theoretical design procedure of the proposed BDC including mixed-mode scattering matrix, even- and odd-mode analysis, and phase analysis is discussed in detail. To demonstrate the performance of the proposed structure, a BDC is designed and fabricated at 2.4 GHz on Rogers RO4003C substrate. The measurement results show that a 15-dB differential coupling level with 3-dB ripple in the frequency range of 1.7-3.3 GHz has been achieved. Also, great common-mode suppression is obtained in full operational bandwidth. The proposed BDC can be used as a signal sampler in fully balanced radio frequency (RF) systems.