combiner question

[electroRF]

Hi guys,

Is it correct that in a bi-directional 2:1 Combiner - In1, In2, Out - there is a:
1. 3dB loss from Out -> In1 and from Out -> In2
2. no loss from In1 -> Out and from In2 -> Out

i.e.

if:
- In1 transmits 4dBm
- In2 transmits 5dBm
- - Out will receive 9dBm

if:
- Out transmits 6dBm
- - In1 will receive 3dBm
- - In2 will receive 3dBm

 

[JimB]

If the combiner is perfect (most unlikely) the answer is yes.

JimB

 

[electroRF]

Hi Jim,
Thank you

I assume you meant for the Insertion Loss?

i.e. typical inesrtion loss is 0.5dB (approximately), therefore it'd change to:
if:
- In1 transmits 4dBm
- In2 transmits 5dBm
- - Out will receive 8dBm

if:
- Out transmits 6dBm
- - In1 will receive 2.5dBm
- - In2 will receive 2.5dBm

I doubled the insertion loss as you can see, but i'm not sure if its correct.

 

[JimB]

I assume you meant for the Insertion Loss?

Yes.

RF combiner/splitters are simple yet interesting devices.
If you want to know more about them, have a look here at the MiniCircuits website.
**broken link removed**
This link takes you ro the application notes, there are lots of them. Scroll down, and near the bottom of the list you will find a section for Power Splitters/Combiners.
There you will find an FAQ and a section Understanding Power Splitters.

JimB