Jan Schur

Design of new passive THz devices based on micromachining techniques

We present an overview on the latest results using micromachining techniques for the fabrication of THz-components. Different machining techniques was discussed with respect to their capability to generate complex 3-dimensional geometries with high aspect ratios and to meet the high mechanical requirements for THz-components. Exemplary results for the application of micromachining techniques for the design of new components were reviewed. We emphasizes the potential of silicon based microstructures for the manufacturing of new devices.

A 4 th harmonic schottky diode mixer - facilitated access to THz frequencies

This paper will present first measurement results of a 4th harmonic Schottky diode mixer operating at 600 GHz. The mixer design compromises a rectangular waveguide based splitblock with an integrated quartz based mixer circuit. A low parasitic planar antiparallel Schottky diode pair is used to downconvert a 600 GHz signal by mixing with the 4th harmonic of the local oscillator. The local oscillator for the presented mixer consists of a 150 GHz PLL-locked frequency doubled Gunn oscillator providing a frequency and phase stabilized LO source for accurate measurements of the magnitude and phase of the RF signal. Simulations predict conversion losses well below 20 dB. Current evaluations of the mixer performance are proving the suitability for short range applications like material characterization and testing as well as for life sciences and medical applications.

Micromachined split-block Schottky-diode mixer for 600 GHz

This paper presents simulation results for a 600 GHz micromachined waveguide mixer with integrated horn antenna, a hybrid-integrated planar Schottky diode and IF filter structures on a quartz substrate. In addition to the simulated electrical performance we show approaches for the manufacturing of the split-block mixer by both micro-mechanical milling and silicon etching technology.

600 GHz GaAs Schottky diode mixer in split-block technology

In this paper we present measurement results of a micro-machined split-block waveguide mixer for 600 GHz. The mixer implements a planar GaAs Schottky diode on a quartz substrate. Two different diode designs used for this mixer design are compared. The overall performance of the waveguide mixer is demonstrated by measurements of the mixer in a quasi-optical setup at 600 GHz. In this setup we are able to measure single sideband conversion losses of 9-14 dB at 600 GHz and voltage responsivities of 421-1690 mV/mW.

Antenna concept for an Automotive Radar Sensor at 150 GHz

Current Automotive Radar sensors operate in a frequency range up to 81 GHz to provide distance, velocity and angle information about traffic objects. For detecting weakly reflecting objects in presence of a nearby strong reflector (e.g. a person standing close to a van) there are high demands on a radar systems angular resolution. A possibility to improve the angular resolution is increasing the operation frequency. In this paper an antenna concept at 150 GHz is presented showing the benefits of high resolution radar for cars.

Design of a 4 th harmonic Schottky diode mixer for THz frequencies

This paper focuses on the benefits of subharmonic mixers in the sub-mm wavelength range. To demonstrate the possibility to extend the advantages of 2nd harmonic mixers with respect to local oscillator requirements the paper discusses higher order subharmonic mixers. Simulation results are presented to show the achievable performance and limitations of higher order subharmonical mixing. For an exemplary 4th harmonic mixer operating at 600 GHz the circuit simulations predict a conversion loss of around 15 dB. Results of 3D-EM field simulations are presented to demonstrate a very compact split-block realization of the mixer circuitry.

A Heterostructure Barrier Charge Swing device for frequency multiplication at 306 GHz

A new type of frequency multiplier which is called Heterostructure Barrier Charge Swing (HBCS) is proposed. It concerns a bunch of charge carriers swinging in a trough between heterojunction barriers. The behavior of the device is simulated and experimentally verified. Efficiencies of 27% for tripler and 14% for quintupler operation are predicted. A split-block mount with planar circuitry is presented to prove tripler operation capabilities from 102 GHz to 306 GHz.

Technological issues for micromachining of new passive THz-components based on deep-trench silicon etching

We present a survey of the application of micromachining techniques for the fabrication of THz-components. Micro-machining of new THz- devices based on deep trench etching of silicon is discussed with respect to its capability to generate complex 3-dimensional geometries with high aspect ratios (ARs) and to meet the high mechanical requirements for THz-components. First results for the application of deep trench etching for the design of a branch-line coupler for 600 GHz is discussed. We emphasize the potential of silicon based microstructures for manufacturing new devices and focus on technological issues.

MOS-16: A new method for in-fixture calibration and fixture characterization

The calibration of test fixtures or the estimation of their performance are well known tasks. In the case of fixtures with variable length, there are some established methods to de-embed the DUT (Device Under Test). The calibration or evaluation of a fixture with a fixed length, like a socket or a probe-card offers less possibilities. This contribution presents a novel calibration procedure, capable of gathering not only the information required for a proper de-embedding but also for an absolute characterization of fixed length fixtures, including crosstalk. In order to achieve this, specific assumptions have to be made. These assumptions, the resulting calibration scheme as well as a first validation through a known device will be addressed together with a first discussion on error propagation.

Wireless chipless cure monitoring sensor for fibre-reinforced plastics

In this work, a novel fully passive chipless wireless cure monitoring sensor for fibre-reinforced plastics (FRP) structures is presented. The sensor is the first system that enables locally wireless monitoring of the rising cross-linking level of the polymer molecules and the reaction temperature of epoxy resins during the exothermic curing reaction at particular critical locations inside FRP structures. The temperature and permittivity of the reacting epoxy resin composition is determined by measuring and evaluating the change in resonance frequency for two substrate integrated waveguide (SIW) resonators. The measurement results obtained show an excellent accordance with the data provided by the widely used, and established, cure monitoring technique, differential scanning colorimetry (DSC).