A W-band surface micromachined monopole for low-cost wireless communication systems

A W-band CPW-fed 3-D quarter-wavelength monopole that is vertically mounted on a variety of substrates is reported for the first time. A transition from coplanar waveguide to vertical coaxial structure is investigated. The structure demonstrates broadband impedance matching and symmetry radiation pattern in W-band. Greater than 10 dB return loss over 19 GHz bandwidth is measured on chromium coated soda-lime glass substrate, while over 10 GHz bandwidth for silicon and sapphire substrates is also observed in simulation. As a low-cost solution without etching requirements, this idea can be easily extended to integrate with other RF front-end components and to design more compact millimetre wave systems. Experimental and numerical simulation results are provided to demonstrate the effectiveness of the idea.