Looking for assistance to widen the frequency band for RF Splitter

Thread Starter

SteveMorgan

Joined May 14, 2012
6
Hi All,

Looking for some assistance please in regards to expanding the frequency band on some RF Splitters.
Currently they are rated from 5MHz-2Ghz. They look pretty standard with some inductors and capacitors, I'm assuming that the inductors are mainly for impedance matching purposes and the capacitors are what I need to target to increase the frequency range? Trying to get them to between 100KHz-2GHz, so want to increase the lower end of the range. This doesn't have to be perfect, but any improvement suggestions appreciated. I can't tell if the capacitors are in series with the signal or in parallel from signal to ground which I know will make a difference. No values on anything, everything is surface mount with the exception of the inductors but measuring some capacitors in circuit I am seeing around 4-7nF. Others even within the same circuit only a few pF.
Any advice greatly appreciated. Thanks in advance.

Regards

Steve
 

Papabravo

Joined Feb 24, 2006
18,408
IMHO you have no idea what you are up against. At frequencies above 100 MHz., the lumped components are the least of your problems. The magic is in the layout and orientation of the traces, their length width, and separation. Without the proper test equipment, you will have no way to test the efficacy of any modifications you may make.
 

Ya’akov

Joined Jan 27, 2019
5,659
A splitter that broadband is a serious undertaking. As @Papabravo has said, it isn’t just a matter of chanting out components.

A goto source for such devices is Mini-circuits. You haven’t mentioned the application which is very important in providing a solution. Could you give us some idea what problem this splitter is intended to solve?

Mini-circuits has this one at 75Ω that does DC to 2GHz, but I don’t know what impedance you need, or if it will even do what you expect it to.
 

Thread Starter

SteveMorgan

Joined May 14, 2012
6
Thanks both for taking the time to reply and apologies for the delay in my response. I may have not made it clear, I am trying to modify *Existing* 5MHz-2GHz RF splitters, so just trying to widen their low end a bit. I appreciate there is a lot more to this, but I don't expect the results to be perfect . I have no way to measure the results other than an improvement in reception at the low end - I appreciate that this could result in a detrimental result in the top end, but I just need some tips/guidance as to what I should be playing around with. The end game is to be able to provide a wide band signal through out a house so that no matter what type of receiver (FM/AM/SW etc) in whatever room I am in I can get some reception. I appreciate this isn't ideal but ideal isn't the plan, at least for now. All I am after right now is something functional in a 100kHZ-2GHz region, rather than the current 5Mhz-2GHz I am limited to right now. Any helpful tips appreciated.
 

Papabravo

Joined Feb 24, 2006
18,408
I made a cursory check, and I can't find splitters that go that low in frequency. I think that might be an indication of the difficulty you will be facing.
 

sparky 1

Joined Nov 3, 2018
716
I did a quick search but widest I found was this. Using an upconverter comes to mind to include the lower bands.

Specification:

Frequency Range: 100-2700MHz
Standing wave ratio VSWR: ≤1.4
Isolation: ≥20dB
Insertion Loss: ≤1
Passband Ripple: ≤0.3 dB
Phase Imbalance: ≤ 3°
Impedance: 50Ω
Maximum Input Power: 25W
Cost 3.99

wideband splitter.jpg
 
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