A dual-window coupled dual-mode cavity substrate integrated waveguide (SIW) filter is proposed for automated guided vehicle (AGV) point-to-point communication, where two pairs of transmission zeros (TZs) are achieved on both sides of the passband. The dual-mode cavity is realized by inwardly folding one corner of the SIW cavity, with a perturbation via placed at the diagonal position. The TE102 and TE201 modes are mainly utilized by the dual-mode SIW filter. Coupling between the two cavities is achieved through openings in the via wall, and the position of the first resonance point in the passband can be adjusted by changing the width of the coupling window. The second and third resonance points can be altered by adjusting the distance of the perturbation via from the sidewall. The positions of the TZs on both sides of the passband can be modified by adjusting the offset distance of the input/output ports from the centerline and the length of the folded angle from the sidewall. Magnetic coupling between the two dual-mode SIW cavities is achieved through a dual-window structure, resulting in two pairs of TZs on either side of the passband, thereby improving frequency selectivity. A fourth-order SIW filter with two pairs of TZs has been simulated, fabricated, and measured. The measured frequency response shows good agreement with the simulated results, with a center frequency f0 of 29.3 GHz, a minimum insertion loss of 1.4 dB, and a return loss better than 11 dB. Four TZs are observed at 24.68, 27, 31.06, and 35.12 GHz, with suppression better than 20 dB. The filter can be applied in wireless electromagnetic systems, such as microwave sensor systems, 6G mm-wave communication, or point-to-point communication for AGV vehicles.