A 3 dB coupler has been designed and implemented using the most commonly used double-sided FR4 boards. The coupling and the bandwidth of the coupler are enhanced with the enlarged overlapped area of the coupler. Major design parameters are plotted as a design guide and the parameters are verified by simulation and measurement. The size of the manufactured coupler is $30{ imes}14mm^2$. Its measured insertion loss and phase difference are 0.6 dB and $90.5^{circ}$ at center frequency of 2.5 GHz, respectively. The operating frequency range is 1.72 GHz to 3.08 GHz for $3.6{pm}0.5dB$ insertion loss. The coupler has the performance similar to that of conventional Lange coupler, and implementation of the coupler is easy and cheap with wide metal width and spacing and no additional wire bonding process.