microstrip travelling wave antenna load

[BasketballJones]

I am trying to design a microstrip travelling wave antenna. The antenna is driven by about a 2watt power amplifier. This type of an antenna requires a load on the other end. What are the power handling requirements for the load? Can I just put in a generic 50 Ohm chip resistor?

Many thanks.

 

[TWW]

You need a matched impedance to prevent the backward traveling wave (that produces a second image beam). The power handling capability of the load obviously depends on how efficiently your forward wave radiates. the antenna pattern and reflection coefficent for a shorted antenna will give you a measure of the amount of power radiated in the forward/backward waves. ie. power in = power radiated forward plus power radiated backward + power returned back to the input. that will give you an estimate to pick a chip resistor with ~2x power handling capability.