An automatic phase control circuit with DLL-like architecture for phased array antenna systems

A phase calibration scheme employing the training mode for phased array antenna systems is proposed. The proposed circuit realizes an automatic phase calibration using a DLL-like architecture which has a PFD and a CP. Two signals from the multiphase LO according to the phase difference of DoA, are put into the circuit and control the phase shifter. The output voltage of the CP controls the amount of the delay, and the voltage level at the locked condition is maintained and employed in the communication mode. The phase shift control in our proposed circuit calibrates not only the delay cell but also the effect of the variability of circuit components and their operation conditions. These two mode were designed using 65nm CMOS process and the simulation results show that our proposed scheme achieves optimal delay control in the training mode. Therefore, the input signals of the system are combined in-phase in the communication mode.