Presentation

Measurements at THz frequencies employ two disparate classes of instrumentation platforms, free-space THz measurements (which evolved from optical spectroscopy) or waveguide-based (which are an extension of electronic RF measurements, predominantly made with heterodyne Vector Network Analysers, VNA) . Among these two, only waveguide-based provide calibrated measures and therefore is the main platform for phase sensitive measurements in electronics. Broadband VNA instrumentation uses standardized coaxial cables and connectors, which increase their maximum frequency as their dimension reduces. The physical limit of standard fabrication technology has been reached with the 0.8 mm coaxial standard, which has a maximum cut-off frequency of 166 GHz and shows high losses, 18 dB/m @ 110 GHz. To increase the maximum frequency beyond this limit, rectangular waveguide coupled extender heads must be used, which segment the frequency spectrum into separate bands.

TERAmeasure vision is to establish the basis for a radically new measurement paradigm in the millimetre (MMW, 30 GHz–300 GHz) and Terahertz (THz, 300 GHz–3 THz) frequency ranges, overcoming the current obstacles to better measurements, eliminating the frequency banded nature of rectangular waveguides and providing metrology-grade results across the full frequency range.

TERAmeasure aims at replacing costly frequency-extension modules, relying on rectangular waveguide flanges, by a photonic approach that covers the full spectrum from 30 GHz up to 3 THz. Thereby, TERAmeasure helps to unify the MMW and THz spectrum, which is currently segmented into more than 10 separate bands. TERAmeasure challenges the established pathway that high frequencies can be addressed only by further miniaturization of the components, which will run into fundamental physical limits.

This breakthrough will be achieved exploiting photonic integration technology and silicon micromachining to realize a broadband continuous-wave THz platform equipped with refractive index engineered dielectric waveguides. We aim to stimulate novel fields of research, field resolved near-field microscopy and industrial non-destructive evaluation

TERAmeasure aims at replacing costly frequency-extension modules, relying on rectangular waveguide flanges, by a photonic approach that covers the full spectrum from 30 GHz up to 3 THz. Thereby, TERAmeasure helps to unify the MMW and THz spectrum, which is currently segmented into more than 10 separate bands.

TERAmeasure challenges the established pathway that high frequencies can be addressed only by further miniaturization of the components, which will run into fundamental physical limits.

Key objectives

To realize this vision, we propose the unique combination of photonic integration technology (to realize a continuous-wave THz signal generation and phase sensitive detection) and silicon micromachining (to engineer the permittivity of dielectric waveguides creating THz lenses in the material). The concept is to develop two subsystems, a wideband non-contact transceiver head and a photonic-based VNA.

To achieve this vision involves the following project objectives:

• Photonic-based integrated transceiver chip, led by Fraunhofer HHI
• Micromachined dielectric waveguide structures with lensing patterns, led by KTH
• Photonic-based VNA platforms with calibrated phase sensitive measurement procedures, led by ANRITSU

These objectives aim to remove the segmented frequency band nature of VNA measurement platform imposed by rectangular waveguides, developing the concept for a non-contact transceiver head enabling calibrated phase-sensitive measurements over the entire MMW/THz frequency range (30 GHz to 3 THz) with a single device, reducing the sources of measurement uncertainties in two-port S-parameter using an Anritsu VNA

TERAmeasure Concept

TERAmeasure Applications

TERAmeasure in figures