Page 1 of 1

Do we need any Balun filter for RF designs?

Posted: Sat May 02, 2020 9:56 am
by MCUism
Hi ,

I have been working on a RF design with ESP32-PICO-D4. In the datasheet it is mentioned that Wifi Radio output impedance is 50 ohms. I'm going to use this board for a BLE application.


1. There is no details about output impedance for Bluetooth section(is it same as Wifi Radio output impedance)?

2. I am using the Johanson technology's SMD Ceramic Chip antenna https://www.snapeda.com/parts/2450AT18B ... datasheet/ which has an impedance of 50 ohms. i am anyways trying to design a 50 ohm feed trace to the antenna (I am not going to use recommendation circuit of the antenna manufacturer). What extra things should I need to take care of in case of my design.

3. Should I use any external filters or impedance matching circuitry's? please help me out.

Re: Do we need any Balun filter for RF designs?

Posted: Sat May 02, 2020 3:33 pm
by ESP_Sprite
There is only one radio in the module, WiFi and BT/BTLE both share it. I'm not sure about the technicalities of connecting an antenna, but perhaps the hardware design guidelines have some more information you can use.

Re: Do we need any Balun filter for RF designs?

Posted: Sat May 02, 2020 5:33 pm
by MCUism
Hi ESp_Sprite. Thanks for the reply. I already referred to that document. But as the antenna that I am gonna use is a different one the matching circuits are completely inappropriate. That's the reason why I have posted my question here.