Abstract
It was my first experience to manufactured a 3 elements Yagi-Uda array antenna for the ham radio when I was 20 years old. Since then I have dedicated to developed many antennas for these 50 years, which called the centerline driven loop antenna, the twin delta loop antenna, the modified transmission line antenna, the parallel transmission line loaded loop antenna with reduced size, the parallel transmission line loaded multi-band loop antenna, the double folded mono-pole antenna, and the circularly polarized normal mode helical antenna. I also reported principles of the developed antennas in many conferences or my books. In this report, I would like to introduce the historical back ground or episode with relating to these antenna developments.
