how to connect dipole antenna

hi, everyone,

could anyone help me on antenna measurement?

1, how to connect a dipole with VNA?

2, the antenna is designed for a chip in RFID system. should i measure it with chip or without chip? what is the difference?

thank you very much.

1. You can put a Balun between the VNA cable and the dipole antenna.

2. The antenna is the source, and the chip is the load. Don't mix them together.

By the way, I assume that you know the impedance of RFID IC usually is not 50 ohm, unless you matched it to 50 ohm.

Good luck

thank you very much.

i have got some ideas from publications, but i have no experience for measurement. should i design a special balum for my dipole or there are some standard product for balun?

http://www.swissatv.ch/documents/2.4...le_antenna.pdf

i am still confused on balun. i am designing a dipole matched to a chip. there is no integrated balun in many design. why is it need when measurement? can i use the extra balun product only for measurement?

thank you very much.

Are you measuring the impedance of the dipole or the chip?
1. If it is a dipole, then you need a simple balun.
2. If the antenna and the chip are integrated together, then the chip impedance can be measured directly.

my dipole is designed to connected with chip. but i will measure the s-parameter and impedance without chip. now, i have the problem how to connect it with VNA. does anyone have the experience on connect the printed dipole to VNA?

thank you very much.

I also got the same issue since I find the S11 is the same for a chip antenna even I place the matching components or not. Should I need to add a balun duting the measurement? Thanks a lot.