Y. T. Lo, S. W. Lee and Q. H. Lee, Proc. IEEE, 54(1966),1033.[2]D. K. Cheng and F. I. Tseng, Proc. IEE, 114(1967), 589.[5]R. R. Kurth, IEEE Trans. on AP, AP-22(1974), 103.[6]B. Wardrop, Marconi Rev. (GB), 38(1975), 184.[7]N. Goto and Y. Tsunoda, IEEE Trans. on AP, AP-25(1977), 896.[8]F. Hodjat and S. A. Hovanessian, IEEE Trans. on AP, AP-26(1978), 198.[9]O.Elnarsson, IEEE Trans. on AP, AP-27(1979), 86.[10]刘振威,电子学通讯,1(1979), 118.[14]刘振威,电子学通讯,1(1979),163.