A Forked Photodiode Array (F-PDA) electrodes were presented to address the issues brought by transmission delay of traditional Traveling-Wave Phohodiode Array(TW-PDA), which cause phase-mismatches of electrical signals and affect the overall frequency response. This design overcomes the problems cited above by using a symmetric-connected structure instead of the cascade-connected structure of TW-PDA to ensure that the terminal pad is equidistant from each unit. The structural parameter of F-PDA is simulated and optimized by using simulation software HFSS. In the simulation, the characteristic impedance is kept at about 50 Ω and the insertion loss is less than 1.5 dB within the boundary of 100 GHz. Traditional and forked structures were fabricated and tested in experiment. The results show that the forked structure has a better performance compared with the traditional structure. At 40 GHz, the later has an insertion loss of 2.5 dB and a 3 dB bandwidth of 6.9 GHz, correspondingly, the properties of the former are 1.36 dB and 13.8 GHz.