The integrated waveguide optical delay network for four-element sub-phased array antenna at Ka band (30 GHz) is designed, in which, the radio frequency (RF) signal is converted into the optical domain by the phase modulation and the waveguide micro-rings operate at the anti-resonance state to achieve large bandwidth and continuously tunable time delay. Only one sideband is delayed via the bandpass filtering and the RF signal is recovered by the differential balanced detector. The structural parameters of the cascaded dual waveguide micro-rings are optimized to achieve the continuously tunable time delay in the range from 0 to 24.9 ps, and the bandwidth is larger than 4 GHz. The beam scanning with the maximum scaning angles of ±30° is realized. The gain and noise coefficients of the optical time delay network are analyzed and deduced, and the performance of the whole delay chip system in the practical application is evaluated.