Lithographically defined integrable air-lifted bow-tie antennas

A vertically placed monopole type bow-tie antenna has been fabricated using dynamic mode multidirectional ultraviolet (UV) lithography and polymer metallization on a non-transparent printing wiring board. A photopatternable liquid state polyurethane is utilized to define a bow-tie antenna backbone with a height of 4.5 mm, a top portion width of 3 mm, a bottom portion width of 800 ¿m, and a flare angle of 30°, which allows a resonant radiation frequency of 12 GHz. The printing wiring board with a thickness of 508 ¿m has a drilled hole with a diameter of 800 ¿m through which backside tilting exposure has been performed to define the vertical bow-tie slab. Conductor backed coplanar waveguide (CB-CPW) has been used for feeding the air-lifted bow-tie antenna. The measurement results show a resonant radiation frequency of 12.34 GHz and a 10 dB-bandwidth of 7%. It shows an omnidirectional far-field radiation pattern based on simulation. Different shapes of air-lifted backbone for 12 GHz resonant radiation has been fabricated and the performance has been simulated using a high frequency structure simulator tool.