RFX2401C and matching netowrk with nRF24L01+

RE: RFX2401C and matching netowrk with nRF24L01+

bjorn-spockeli — Mon, 18 Apr 2016 07:58:07 GMT

Yes, the 2450BM14A0002 can be used between the nRF24L01+ and the RFX2401C. The benefits are reducing component count, system variability, implementation size area, and PCB sensitivity, see this page on the Johanson website.

RE: RFX2401C and matching netowrk with nRF24L01+

Joe Wright — Fri, 15 Apr 2016 14:19:33 GMT

Thanks that's great. With such a PA, can the Johnson 2450BM14A0002 balun be used between it and an nRF24L01+. And if so, is there any advantage?

RE: RFX2401C and matching netowrk with nRF24L01+

bjorn-spockeli — Fri, 15 Apr 2016 12:14:42 GMT

I understand your confusion and I'll try to explain why the external matching network is needed.

The RFX2401C has internal matching networks on the TXRX and ANT pins to ensure that the input and output impedance are matched to 50 Ohms.

However, allthough the input impedance of the RFX2401C TXRX pin has been matched to 50Ohm, it does not mean that the impedance will still be 50Ohms after connecting it to the nRF24LE1. The ANT lines coming out of the nRF24LE1 must also be matched to 50Ohms before you connect it to the RFX2401C TXRX pin.

The same will apply for the antenna, it must also be matched to 50 Ohms before connecting it to the RFX2401C ANT pin.

-Bjørn