Disclosed is an integrated circuit device in which a 90-degree phase shifter is implemented. The 90-degree phase shifter includes four input capacitors all having equal capacitance and four output capacitors all having equal capacitance. The input capacitors and the output capacitors are alternately...http://www.google.com/patents/US6822496?utm_source=gb-gplus-sharePatent US6822496 - Integrated circuit device implementing 90-degree phase shifter capable of generating output signals having phase difference therebetween at improved accuracy
