Controlling a switched beam array antenna using PLL frequency synthesizers based on the congruence modulo

This paper presents a method of designing the required reference signals' phases for a group of frequency synthesizers based on the congruence modulo. The resultant adjacent synthesizers' outputs possess a constant phase difference that the synthesizers can be used to control the steering beam of an array antenna. Compared with the conventional phase shifter approach, the frequency synthesizers' output phases can be accurately controlled at different frequencies as long as their input reference signals' phases are well-controlled. Compared with the other phase control mechanism using frequency synthesizers for controlling the feeding phases to an antenna array, the proposed congruence-modulo-based method is easier to be realized and the resultant system is less complicated.