Experimental characterization of a coherent multi-carrier Tx-Rx system based on Rationally Synchronized Oscillators

In this work, a coherent Tx-Rx system, which generates two carrier signals with frequencies f_o,1=3 GHz and f_o,2=3.75 GHz, with a known constant phase relation with a reference signal, with frequency f_r=5 GHz, is designed, analyzed and implemented in microstrip technology. In order to experimentally characterize the behavior of the system, the transmitter output signals are connected to a Vector Network Analyzer, which provides the reference signal and measures the phase shift reached between the RSO output signals and the reference one. The receiver is characterized assuming that the phase shift suffered by the reference signal, which is also provided by the VNA, is 0°. Hence, the phase of its output signals can be measured in a similar way as in the case of the transmitter, in order to calculate the absolute error achieved. In addition, the influence of the most relevant working parameters on the achieved error will be analyzed.