It is significant to study the influence of microwave phase noise on the microwave mixing signals with cesium Rydberg atomic antenna. In this paper, the influence of microwave phase noise on the microwave mixing signals based on Rydberg atom is studied theoretically and experimentally. Theoretically, the function of the change of the microwave mixing signal intensity after adding phase noise to the signal field is obtained by summarizing the phase noise term detected by the transmission of the probe laser through the medium. We perform a theoretical diagram that simulates the transmission spectrum of the probe laser as a function of input phase noise. From the theoretical simulation diagram, it can be seen that the microwave mixing signal based on the Rydberg atomic antenna increases with increasing power of the signal field. For the same signal field strength, the microwave mixing signal gradually decreases with the phase noise added increasing. Experimentally, we build an atomic antenna based on the Rydberg atom, which manipulates the Rydberg atom through a reference field, and the Rydberg atom transmits the frequency of the microwave mixing signal directly to the probe laser. Microwave field frequencies of 13.806 057 GHz and 13.806 000 GHz are mixed based on the Rydberg atomic electric dipole transition of 64S1/2→64P1/2 under electromagnetically induced transparency (EIT) spectroscopy of Rydberg atoms in a cesium atomic gas chamber at room temperature. The parameter dependence of the microwave mixing signal intensity was studied by using the Rydberg-EIT spectroscopy. The experimental results show that the microwave mixing signal intensity based on the Rydberg atomic antenna is related to the power of the reference field, the microwave mixing signals enhancement of about 20 dB can be achieved in the reference field under the condition of optimizing the power parameters. When the reference field manipulates the Rydberg atoms to the maximum microwave mixing efficiency, phase noise is added to the signal field. It has been found that when phase noise is introduced into the signal field, it leads to the mixing signal significantly reduced. The experimental results of the influences of the microwave field phase noise upon the microwave mixing signal with cesium Rydberg atomic antenna are the same as the theoretical analysis. This shows that the construction of atomic antennas based on Rydberg atoms to achieve microwave mixing signal opens up the application of different approaches such as communication applications, near-field antenna measurements and radar, and also opens up a wider application of Rydberg atomic sensors in current technology.