Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

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

Rectangular Patch Antenna

Status
Not open for further replies.

ilece

Electrical
Apr 30, 2009
1
I came across this when reading Antenna Theory 3/e by C. A. Balanis. He says a rectangular patch antenna can be represented by two radiating slots, separated by half-wavelength. Each slot is represented with a parallel equivalent admttance. If the admittance of the second slot is transformed over half-wavelength to the location of first slot, then susceptances of the two slots have opposite signs. Adding the two susceptances makes the total input susceptance equal to zero.

I am confused about this: if you transform an admittance over half-wavelength long transmission line, wouldn't the admittance be unchanged? Essentially, the impedance rotates a full circle on the Smith Chart. But Balanis says the susceptance would acquire a negative sign.

I hope someone here could resolve my question. Thanks.
 
Replies continue below

Recommended for you

A full circle on the Smith chart is 180 degrees of phase. Thus a perfect inversion (cos(pi) = -1).

Z
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor