Hi Graham... off the top of my head......I may be mistaken..... its a bit
late :-)

1. The input signals must be in phase
2. The output will be the sum of the input powers less a little that will be
lost in the loads due to a less than infinite isolation between the input
ports. Also both input drivers must look like 50 ohms I believe or there may
be some matching loss too?

This is why if one of combined set of amps fails you dont lose everything.

Well that should stimullate someone, who really knows, to tell me I got it
wrong :-))

Alan G3NYK

----- Original Message ----- 
From: "Graham" <[email protected]>
To: <[email protected]>
Sent: Tuesday, December 06, 2011 12:04 AM
Subject: LF: 5 port combiner transfer function ?


5 port  combiner transfer function ?

 5 port  combiner  , config

2    ports      50  ohms      load
2    ports    power  input     50 ohm
1    port    power  out      50 ohm

Is  the  power  out  simply   i/p 1 + i/p2  =   o/p ??

or  do  the  p1 and p2   powers  need to  be closely  matched
if  so  how  closely ??

Tnx -G