In this paper, we report a wideband energy harvester where mechanical coupling of the cantilever beams in cascaded configuration employed using long and thin spring like structures to couple individual harvesters. The outcomes of designing uni-beam, dual-beam, tri-beam, and quad-beam coupled energy harvesters are compared using COMSOL as well as experimentally. Simulation results indicated that quad-beam coupled energy harvesters had a bandwidth of 11.9 Hz. Physical devices were fabricated in silicon and tested using PVDF-TrFE piezoelectric material and showed a bandwidth enhancement from 0.7 to 8.9 Hz. The coupling scheme may be extended to larger arrays to increase bandwidth further as per requirements.