The lumped-element Y-circulators are often used between the output of
the transmitter and the antenna, for example, in portable movable comm
unication equipment. The frequency bands, however, exist at about 0.9
and 1.8 GHz at present. We have developed the lumped-element Y-circula
tor available to the two bands, which will be used for small, portable
movable communication equipment for the two bands in the future. (C)
1998 John Wiley & Sons, Inc.