impedance matching for dipole antenna @ UHF

[sudokubk38]

please help me:
I design a dipole antenna RFID tag, I want to increase imaginary part to 750 Ohm. thanks very much!

 

[vfone]

Probably is about a small printed dipole, and you can use a gamma match, which allow tuning the impedance match of the antenna.

 

[sudokubk38]

can you please explain clearly, my friend? impedance value of chip is 36-j750 Ohm. when I use stub to impedance matching but input impedance of antenna just increases about 10+j250 Ohm.
more than, I must obtain broadband from 860-960 MHz. please help me! thanks very much!

 

[vfone]

Printed Dipole Antenna

 

[sudokubk38]

Thank you very much! I am researching that. By the way, could you please help me about:
"I have a RFID dipole antenna (microstip line), I want to measure input impedance and return loss so that I compare with simulating. But I don't know anyway. Could you please help me?" Thank you in advance!

 

[RCinFLA]

Any match stub must run perpendicular to antenna. Any ground plane or components near antenna will effect it. You need a balun to convert to balance line to measure dipole.

Attached is a drawing for an unbalanced to balanced tranformer for making measurements. It can match impedance or transform an S parameter to another impedance plane.