Can anyone help me with the L-shaped monopole antenna

i am new to HFSS.Recently i have a problem in design the model of L-shaped monopole antenna.i am confuse of how to draw the junction between the horizonal cylinder and the vertical cylinder.Fig 1 is the configuration.

.Fig 2 and Fig 3 are my designs

.But neither match exactly with the article.Could anyone help me design the model,especially in the junction.Great thanks.

Could anyone help me?Help!