We designed and fabricated a high-bandwidth, 32-pixel, two-dimensional photodetector array (2D-PDA) for receiving transmission signals from multi-core and few-mode fibers. Pixel sizes of 10, 20, and 30 μm were employed, with a pixel gap of 14 μm. We obtained 3 dB bandwidths of 23.8∼29.8 GHz, 19.1∼20.8 GHz, and 9.0∼13.7 GHz for pixel sizes of 10, 20, and 30 μm, respectively. The device exhibited increasing noise due to RF crosstalk, which was caused by neighboring wires or pixels. In this study, we explored different pixel arrangements to reduce the crosstalk between neighboring pixels, and confirmed the frequency characteristics of the 2D-PDA pixels. Moreover, using electromagnetic simulation software, the RF crosstalk of -30 dB between neighboring pixels was confirmed up to the 10-20 GHz range. The crosstalk analysis, crosstalk reduction design in 2D-PDA devices, and its experimental results are displayed and discussed.