Original poster: "Gerry Reynolds" <gerryreynolds@xxxxxxxxxxxxx> Hi Jim,I've never thought of the inverse square law the way you describe it. It sounds like the only way to "not have an inverse square relationship" is to have a beam that has absolutely NO DIVERGENCE and physics would preclude this. No matter how small the divergence angle is, it will cause the cross sectional area of the beam to be 4X larger at 2X the distance with respect to some other point along the beam.
Is this interpretation correct??? Gerry R.
Original poster: Jim Lux <jimlux@xxxxxxxxxxxxx>"inverse quare' is The Law FOR OMNIDIRECTIONAL sources.That's for ANY radiative source with any directive properties when you are in the far field.Each unit radius out from the source the energy gets 'spread more widely', becomes 'thinner'. (To put it in non mathematical terms.) However. Ponder, please, a 'Very Well Collimated' beam. Parallel. BIG 'reflector', meaured in wavelengths. The beam (laser, microwave) does not get bigger. I believe this was the concept for the 'rectenna' driven concept.Still have inverse square law, the power is not evenly distributed over the sphere. But, make the sphere twice as big, and for any spot along a line from the center of a sphere, the power density at the bigger sphere will be 1/4 of that at the smaller.