Hisahiro Kai Jiro Hirokawa Makoto Ando Circularly Polarized Post-wall Waveguide Slotted Arrays. 7-12 2004 1 IEICE Electronic Express 1 http://joi.jlc.jst.go.jp/JST.JSTAGE/elex/1.7 db/journals/ieiceee/ieiceee1.html#KaiHA04