Design of Multi-Channel Microwave Photonic method for earth observation satellite

Summary form only given. Fiber optics, which has some advantages such as electromagnetic interference immunity, high bandwidth, low mass and mechanical flexibility, are used in the payload of Soil Moisture, Ocean Salinity (SMOS). But in the SMOS, it needs to distribute the Local Oscillator, the calibration microwave signal and the clock reference to the 72 microwave receivers. This paper demonstrates a possible microwave photonic evolution method (MPEM), which can directly transmit the Y-shaped antennas received microwave signals to the Control and Correlator unit (CCU) parallelly by microwave photonic links. The MPEM is shown in Fig. 1. The optical harness mainly consists of E/O, O/E and fiber links. The received microwave signals are analog converted to optical signal by E/O, and then transmitted to the CUU parallelly by 144 microwave photonic links. At the CUU, the received microwave signals are generated by O/E. Compared with the existing SMOS optical link, it does not need to distribute the Local Oscillator, the calibration microwave signal and the clock reference to the 72 microwave receivers. The linearity and noise figure of microwave photonic links are measured with single frequency signal resource and noise source. The measured results show that the linearity of the microwave photonic links with noise source is 0.999772689 (show in Fig. 2), which suits to the performance requirements of SMOS. And this Multi-Channel Microwave Photonic Scheme can be used to other satellite payload with arrayed microwave signal receivers.