Rotman Lens

> The principle was first published by Walter Rotman and R. F. Turner in 1963

Astonishing nominative determinism there

Rotmans are elegant, but these days you can get full-duplex all digital phased arrays for cheap: https://www.crowdsupply.com/scale-rf/quadrf#

Suppose this is connected to a multiple-output RF transmitter (amplifier), what are the advantages/applications of shifting the phases of the signals passively with a Rotman Lens versus shifting the phases of the signals prior to feeding them to the transmitter (i.e. in the generator)? is the main purpose to compensate for different antennae geometry without having to change the signal generator? I guess things are very different when you can't commute everything into your SDR algorithms.

How difficult it is to get a perfect beam in practice? Can one manufacture a flat rotman lense like that to introduce sinc phase shifts - this should yield a well behaved very directed beam? What are the practical challenges in doing so?

If I understand correctly, is the application of this to quickly switch the direction of sending/receiving? Are there any other applications?

Looks deceptively simple. Is there a good source to learn more about how it works?

Looks ripe for a KiCad/Altium footprint.

The type of old school black magick engineering Claude could never.

I was expecting some sort of fungal network with measurable compute on initial glance. Then the article image couldn't help but look quite like the outline of an Earthbound entity.