This HTML & JS site tries to simulate Electromagnetic Waves within a canvas, it can be used to make radars and antennas in 2D.
the UI is lacking, but the simulation is very capable
placePhasedArray(200, 398, 100, 1, 3, 0, false, 500);
(middleX, middleY, Count, Spacing, Freq, inverseFocalPoint, focus distance)
A: place antenna
S: place sensor
W: place wall
X: remove
Scroll-Wheel while in antenna mode: change freq/phase