How to design a 500 watt termination?

Hello.

I want to design 500 Watt coaxial termination at 3GHz ~ 4GHz.

How to select heat sink?

And I can't find 500 watt termination.

Please let me know them and new idea.

Thanks in advanced.

You will have to use power splitters like the Wilkinson type to end with a group of reisistors with good RF performance connected to the heat sink.

Several manufacturers make such resistors.

Hi,

Use a trick, use a length of high quality coax cable to reduce the 500 watts to a level your load can handle. Don't forget that the cable will have to dissipate
the power. You can cool the cable by putting it in a water-tank.
( Don't use the bath-tub unless you are single ! ) :D

http://www.eupen.com/cable/rf/50_ohm...les/index.html

on1aag.

but few handle high power with low passive intermodulation...

If you want low passive intermodulation in multicarrier measurement (> 170 dBc in 2x20 Watt carrier test case) , you needs in most case using more or less distance of coaxial-cable as distrubied attenuator to take down power to 10-20 watt or less before high quality power terminator.

Spinner (germany) has in my own experience good power terminator/attenuator with low passive IM in different power range (many other companys make big terminators, but few have good passive intermodulation in high power level).

In high power lever situation you needs also take attention on used connectors - least N-connectors, possible using 7/16-connectors for low passive IM.