CC1350: RF port impedance

Abhijeet Karandikar

Intellectual 310 points

Part Number: CC1350
Other Parts Discussed in Thread: CC1190, CC1310

Hello,

I want to design a matching network for 50OHM PCB trace and 50Ohm Whip antenna for CC1350.

What is the source impedance as seen from RF_N and RF_P port of the MCU?

I am using 915MHz band.

over 7 years ago

0 FI over 7 years ago

TI__Mastermind 21300 points

In the CC1350 schematic(www.ti.com/.../swrc309), the impedance at the balun's single ended port is 50ohm.

0 PM over 7 years ago

TI__Mastermind 27145 points

Hi,

We recommend to copy our reference design ( Balun+Filter) to avoid any further issues. The Output of Filter (either side of C15 on CC1350 LP) is a 50 Ohm port. So, you can use this port to design your Whip Antenna and matching.

The output of Balun (L12/C22 Junction) is also a 50 Ohm port.

Thanks,
PM

0 Abhijeet Karandikar over 7 years ago in reply to PM

Intellectual 310 points

Hello,

I do not need the BLE section. So, I am removing the RF switch and connect the differential RF output directly to the balun.
1. How would that affect the impedance matching?

I want to put a power amplifier between the source and antenna. Ideally, I would want to place it between the filter and the antenna.
2. How would that affect the impedance matching?

0 TER over 7 years ago in reply to Abhijeet Karandikar

TI__Guru**** 317180 points

If you only need the sub 1 GHz path, follow the CC1310 reference designs. If you want to insert a FEM, see the CC1310+CC1190 ref design.

Sub-1 GHz

Sub-1 GHz forum

CC1350: RF port impedance