What is the difference between a hybrid combiner and a filter combiner?

Both combine signals to a common path, but do so in different ways.

• Filter combiners are band specific devices used to combine signals from different frequency bands.  In a 2:1 combining situation, there is no 3dB combining loss, but there may be a higher insertion loss than that found in a hybrid device.  Microlab has a range of standard diplexers corresponding to the common wireless bands with typical >50dB isolation between input ports. The BK-26N is such a filter combiner.
• The basic 2 input, 2 output hybrid combiner can be used to combine any two signals in the band without interaction of the signals. The two signals, A and B, can be far apart or close together, and each of the outputs will have an output of (A+B)/2. In a 2-to-1 combine, only one output is used, so one of the outputs must be terminated in 50W.  These devices typically offer 20 dB minimum of isolation between input ports.  Microlab/FXR hybrids, such as the CA-84N, offer 25 – 35 dB isolation across the band of 700-2700 MHz for superior performance in broad-band wireless applications.
• Microlab also offers broadband 3 x 3 and 4 x 4 hybrids for multi-input combining applications as may be required in neutral host in-building systems. These can be found as CM-81 and CM-84 series.