Exporting 2D graphics to DXF

Question

I have a design that I've produced in Mathematica, consisting of two sets of Rectangle objects. The second set is a mirror image of the first and was produced with array2 = Scale[#, -1, {0, 0}] & /@ array1.

I'm experiencing two issues when I Export the Graphics object to DXF:

1. The second set of Rectangles doesn't get exported.
2. Each Rectangle gets exported as a pair of triangles.

Mathematica's Graphics output:

What AutoCAD displays:

Importing the DXF file back into Mathematica also shows that the bottom half is missing. I'm at a loss here - what am I doing wrong? Are either of these weird behaviours deliberate?

---

Edit: Here is a snippet of my code. It generates the design for a surface acoustic wave resonator. This consists of two transducers next to two gratings, each made up of metal strips, separated by a certain number of wavelengths.

l = 2; (* wavelength in \[Mu]m *)

d = 25.5; (* cavity length in wavelengths *)
(* NB this is the distance between the fronts of the transducers *)
vRatio = 1; (* how much faster the speed of sound is in the centre \
section *)

nTransducer = 25; (* number of finger pairs in the transducers *)
nGrating = 370; (* number of fingers in the grating *)
(* NB 2 fingers == 1 wavelength *)

fingerLength = 25; (* finger length in wavelengths *)
(* NB finger length is measured from inside edge of the bus-bar *)

SetDirectory[NotebookDirectory[]];
filePath = "2um.dxf";

fingersT = Table[
   Rectangle[
    {-(fingerLength/2 - 1/2) l, y},
    {(fingerLength/2 - 1/2) l, y + l/4}],
   {y, (d*vRatio/2) l, (d*vRatio/2 + nTransducer - 
       1/2) l, l/2}];

(* -- the rest of the transducer is produced in a similar way -- *)

transducer = 
  Join[fingersT, lSquaresTOut, rSquaresTOut, lSquaresTIn, 
    rSquaresTIn] ~Append~ lBarT ~Append~ rBarT;

(* -- a grating is produced above the transducer in the same fashion -- *)

(* This line originally read: array1 = transducer ~Join~ grating; *)
array1 = fingersT;
array2 = Scale[#, -1, {0, 0}] & /@ array1;

diagram = Graphics[array1 ~Join~ array2]
Export[filePath, diagram, "DXF"];

Answer 1

Smells like a bug to me (check e.g. Export to PDF, which works). Scale is only evaluated when rendered... anyway, this works for me (without changing the triangulation thing):

array1 = fingersT;
array2 = array1 /. {x_?NumericQ, y_?NumericQ} :> {x, -y};

As for the triangulation, not much you can do in DXF. Perhaps use PDF or EPS and import that (or try other available Export vector formats. Or export Line primitives and convert those in AutoCAD to a polygon. Alternatively, roll your own DXF export, which may or may not be overkill.