Referred links

Figure 3. Prof. Shintaro Uda. http://webdb3.museum.tohoku.ac.jp/tua-photo/image/C004326-l.jpg 
A better image. http://www.sm.rim.or.jp/~ymushiak/sub.uda.image.2.htm

Ref. 3. https://en.wikipedia.org/wiki/Yagi-Uda_antenna

Ref. 4. http://www.sm.rim.or.jp/~ymushiak/sub.docu.1.htm##%%

Ref. 5. http://www.sm.rim.or.jp/~ymushiak/sub.ire.chart.htm

Ref. 6. http://www.sm.rim.or.jp/~ymushiak/sub.yubook.htm

Ref. 7. http://www.sm.rim.or.jp/~ymushiak/sub.yua.charts.htm