915 MHz coplanar quasi-Yagi — uploaded fabrication gerbers (RS-274X, mm).
  board_5_5.gbr : FR4 board outline (routed/flared frame, windows, 2x coax-entry holes)
  top_5_5.gbr   : top copper (reflector + lambda/4 slotline balun + driven dipole + 2 directors)

Single copper layer on FR4 1.6 mm. The driven dipole is fed across the 2 mm slot at
the driven element; the slot is shorted at the reflector (a ~lambda/4 slotline balun,
unbalanced coax -> balanced dipole). Coax centre -> +y arm, shield -> -y arm -> reflector.
Simulated as-drawn in openEMS: S11 -26 dB, Zin ~46+j1 ohm, resonance 913 MHz.
