How to make 2.5GHz power divider & combiners



Power dividers and combiners are expensive pieces of equipment and finding one for the frequencies you want can be even more difficult. Thankfully these pieces of equipment are not very complex and can be made for very low cost with a performance that acceptable to a hobbyist using low power.

To construct a simple power divider you will require a piece of double sided circuit board and a 100 ohm surface mount resistor. Etch your circuit board on one side only covering the ground plane side with contact to stop acid eating it away. Each section of the divider is 1/4 wavelength long. You only require the V section itself, but the added quarterwave sections leading to each connector help with matching and can be placed at any angle that is convenient for the positioning of the connectors.



Now solder the 100 ohm resistor into place and your done.

I recommend that you mount your divider in a metal box with coax connectors, but there is no reason why you cannot just save a few pennies and solder your coax directly to the board. Remember that the core of the coax or connecter is soldered to the track on the top side and the shield of the coax or the connecter is soldered to the ground plane on the bottom side of the board.

You may use combinations of this circuit and stack them to make two way, four way or even eight way dividers and combiners, they work well in both directions but you should always solder a 50 ohm surface mount resistor between unused tracks and earth or if your using coax connectors, then connect a 50 ohm dummy load to each unused port. If you fail to do this, then you will have an unbalanced load and the circuit will not work properly.




It's now ready for use. You can use this antenna for dividing up an antenna port for diversity. Multiple antennas on a card with only one SMA socket. OR you can use them to share one antenna with several pieces of equipment. An example would be having an AP and a network card sharing one good antenna to save space and coax runs on a mast.

BACK