Pulse shaping for millimeter-wave and terahertz applications in coplanar technology

In this work, a pulse shaper in coplanar technology intended for the unlicensed band up to the THz region is designed, fabricated, and measured. This broadband frequency range is of great interests as it offers very high data rate communication in local area networks. The technique employs tailored coplanar lines that have been designed using an exact analytical series solution of the synthesis problem derived from the coupled-mode theory. The frequency response of the pulse-shaping device introduced in the synthesis method depends on the spectrum of the applied THz impulse generator, application-dependent devices (e.g. antenna) with known responses, and desired THz output response. Here, the desired output pulse is a combination of Hermite polynomials with 5 ps of temporal duration. The designed device has been simulated in the frequency domain and the obtained result of the S11 parameter has been used in the time domain calculation of the output pulse giving good accordance with the desired THz pulse. The prototype has been fabricated with gold metallization on HR-Si substrate by e-beam lithography and lift-off process. A downscaled version with spectral content up to 0.3 THz is also fabricated and measured validating each component of the system.