The cheapest and simplest way to reproduce the "Mann effect", in visualization of electromagnetic radiation is a low cost radar. For example the HB100, selling for $3.99, can be prepared in a couple of minutes: connect red and black wires to the ground and +5 volt terminals of the HB100 module. Connect yellow and black wires to the ground and "IF" (Intermediate Frequency) terminals.
I usually like to twist the wires together to reduce common-mode interference.
The yellow and black wires are then connected to an amplifier of adjustable gain (op amp) that feeds into the dotgraph display.
In the original system in the 1970s I used a long chain of comparators driving silicon controlled rectifiers to control light bulbs.
Then in 1980 the LM3914 chip was introduced which made this a whole lot easier.
Today you can get LM3914 chips in lots of 50 for only $11.18, i.e. a price of less than 23 cents per chip.
So for very little cost you can drive 10 LEDs and reproduce the effect.
And you can easily cascade the chips together, for example, with 50 chips you can drive 500 lights which gives you a 500 by infinity pixel AR display for $11.18 plus cost of LEDs and a few other small miscellaneous components.
Let's start with just 10 LEDs, and then do 3 chips in a row (30 LEDs) and then 10 chips in a row (100 LEDs).