hi
u can this papers from IEEE about microstrip yagi antenna
1-A New High-Gain Microstrip Yagi Array Antenna With a High Front-to-Back (F/B) Ratio for WLAN and Millimeter-Wave Applications by Gerald R. DeJean, Student Member, IEEE, and Manos M. Tentzeris, Senior Member, IEEE
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 55, NO. 2, FEBRUARY 2007
2-A Printed Microstrip Yagi Antenna Array for Millimeter-Wave Multi-Sector Applications by G. DeJean and M. M. Tentzeris
3-Design and Analysis of Microstrip Bi-Yagi and Quad-Yagi Antenna Arrays for WLAN Applications by Gerald R. DeJean, Member, IEEE, Trang T. Thai, Student Member, IEEE, Symeon Nikolaou, Student Member, IEEE, and Manos M. Tentzeris, Senior Member, IEEE IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. 6, 2007