Physics question

> >
> Apart from the structural mass involved in increasing the aperature
> size, what additional high-tech, low mass components would be needed
> to increase aperature size?
>

There are a couple of different concepts for antenna design.

Essentially:

1) A parabolic reflector with a single huge transmitting element. The
technical challenge is to keep the accuracy of the parabolic surface to
within about a 1/10th wavelength over the entire surface

2) A flat phased array, with zillions of equally spaced transmitter elements,
usually klystron tubes. Again, the main challenge is to keep the surface
perfectly flat within 1/10th of a wavelength over the entire surface.

As the aperture increases it becomes more difficult to maintain the required
surface accuracy.

So lots of little SPSes would be easier to build than one humungous one.