Patent ID: 7558361

Claim:
Phase-switching dual modulus prescaler, comprising a dual modulus divider ( 10 ) comprising: a first and second divide-by-2 circuit (A;B), wherein said second divide-by-2 circuit (B) is coupled to the output of said first divide-by-2 circuit (A) and at least said second divide-by-two circuit (B) comprises four phase outputs (I p , I n , Q p , Q n ; INi, IiNni, INq, INnq) each separated by 90°; a phase selection unit (PSU) for selecting one of the four phase outputs (I p , I n , Q p , Q n ; INi, INni, INq, INnq) of the second divide-by-2 circuit (B); a phase control unit (RTU) for providing control signal (C 1 , NC 0 ; C 2 , NC 2 ; C 3 , NC 3 ) to the phase selection unit (PSU), wherein the phase selection unit (PSU) performs the selection of the four phase outputs (I p , I n , Q p , Q n ; INi, INni, INq, INnq) according to the control signals (C 0 , NC 0 ; C 1 , NC 1 ; C 2 , NC 2 ); and said phase selection unit (PSU) is implemented based on direct logic; wherein the output (OUT) of the phase selection unit (PSU) is implemented according to the following logic code: OUT= NC 0 •NC 1•IN i + NC 0 •C 1•IN ni + C 0 •NC 2•IN nq + C 0 •C 2•IN q , +, •, represent an OR-, AND, and NAND functions, respectively.