QUESTION

Question

HI,

My circuit consists of               Wireless MCU->Balun(differential to single end) ->Pi filter-> Antenna(SR42I010-R).

In order to match the antenna, which point i need to consider where i can use vector network analyzer.

should i connect VNA after MCU or after Balun ?

Thanks.

Answer 1

Hi,

To match the antenna connect the VNA cable after balun to measure the matching netowrk and disconnect the path going to Balun. This is so the RF path isn't split into 2.

Best regards,

Yu Kai Yeung

Comments

Thanks for your reply.

The RF path starts from Power amplifier that is inside wireless MCU.

the RF chain is : wireless MCU-> BALUN -> pi filter -> Antenna.

if i disconnect path between Balun and pi filter , how can i guarantee same impedance path between MCU and Balun to  the impedance path between antenna and matching filter ?

Thanks and Kind Regards.

---

Hi,

You can add a 0 ohm resistor at the end of the Pi matching to connect to the Balun, you can connect the VNA directly to the 0 Ohm resistor pad when testing the antenna and matching.

Best regards,

Yu Kai Yeung