T Kawai   T Fukumoto   Y Kokubo   Ohta, I   JP Hsu   
1997 ASIA-PACIFIC MICROWAVE CONFERENCE PROCEEDINGS, VOLS I-III 1145-1148 1997年
This paper describes a design of microstrip rectangular disk quadrature directional couplers on the basis of a modified eigenfunction expansion method with consideration for frequency dependences of an effective width and an effective relative per...