Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Negative Real part Of input impedance

Status
Not open for further replies.

mirok

Electrical
Joined
Jun 27, 2001
Messages
36
Location
CA
Hi

I simulate an inverted patch microstrip antennac using FDTD. the feed structure that I used, was a Gussian Pulse input J-current. Everything is ok. and I almost get good result but the problem is that the real part of input impedance is negative. Can anybody have any comment about that?

tanx

 
the negative real part of the input impedance is due to the lack of energy absorbing layers.
so you need to incorporate some kind of energy absorbing mechanism(like dielectric loading) in your design.

i had the similar problem when i was simulating my antenna using FDTD based Zeland Software.When i increased the number of perfectly matched layers(PML),i could able to get the real part of the impedance in positive.

all the best.
 
Suggestion: Have you tried to increase the antenna thickness?
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top