This work investigates the impact of 3 dB bandwidth on arrayed waveguide grating (AWG)-based Fiber Bragg grating (FBG) interrogator performance. We fabricated four PLC-AWGs with bandwidths spanning 1.76–2.45 nm using photonic integration. Through MATLAB simulations and experimental characterization, we demonstrate that increasing bandwidth improves accuracy from 37.38 pm to 14.34 pm while degrading resolution from 0.82 pm to 1.10 pm. These results quantitatively reveal the bandwidth-dependent resolution-accuracy trade-off, providing critical design insights for FBG-based sensing systems.