Matthias Hoefle

Highly responsive planar millimeter wave zero-bias schottky detector with impedance matched folded dipole antenna

A compact highly responsive planar zero-bias Schottky detector is proposed for uni-planar and low-cost fabrication. Various zero-bias Schottky diodes are investigated, in particular the optimization of impedance matching by the antenna design itself. The realized folded dipole based detector demonstrates an outstanding system voltage responsivity of 7,079 mV/mW at 86 GHz without lenses or pre-amplification.

Compact Schottky barrier diode receiver for E-Band (60–90 GHz) wireless communications

A compact E-Band receiver based on a zero bias Schottky barrier diode, folded dipole antenna and hyperhemispherical silicon lens for wireless communications is presented. Zero bias Schottky diodes were designed and manufactured, and all their parameters were extracted. The folded dipole antenna is designed in such a way that maximum power is transferred from it to the Schottky diode, so the responsivity of the overall receiver will be improved. In addition, a study on the optimal hyperhemispherical silicon lens for this antenna has been undertaken.

Characterisation of low-barrier Schottky diodes for millimeter wave mixer applications

This paper presents the characterization measurements and simulations performed with ACST InGaAs low-barrier Schottky diodes for millimeter wave mixing applications. While these low-barrier Schottky diodes have been successfully used for millimeter wave detector design, their performance when acting as mixers has not been tested yet. This paper shows the performance for this type of diodes in a fundamental mixing configuration with evaluation of conversion loss and noise temperature. A fundamental mixer test-jig is used as the measurement platform with low-loss E-H impedance tuners for RF and LO signal matching. In addition to the measurements, 3D HFSS and ADS circuit simulations are also performed and results are presented. Conversion loss of less than 5 dB is obtained for 0.1 mW LO power in mixer operation at 181-183 GHz.

Millimetre-wave detectors for direct detection radiometers

This paper reports on the activities carried out by Airbus DS SAS, OMMIC SAS and ACST GmbH during the ESA study “Micro and Millimetre-Wave Detectors” A081ET03. Two European technologies for direct detection have been developed and detectors have been designed, manufactured and characterized up to 166GHz, with performances comparable to non-European devices.

High power 150 GHz Schottky based varactor doubler

Presented is the design, simulation and characterization of a high power 150 GHz Schottky based varactor doubler. The designed doubler works in the 67.5 GHz-82 GHz input frequency band with an input power of 25 dBm (315 mW), providing 19 dBm (82 mW) output power (more than 25% efficiency) in the 135 GHz-164 GHz output frequency band (20% relative bandwidth). The design is based on new high power diamond substrate Schottky varactor diodes designed and manufactured by ACST GmbH.

89 GHz Schottky detector modules for MetOp-SG

Presented is an 89 GHz waveguide coupled direct detector based on ACST low-barrier Schottky diodes. Signal-to-noise ratio (SNR) values above 35 dB within 6 dB input power dynamic are achieved with high voltage responsivity of 3000 V/W and significant white and 1/f noise reduction. The fabricated detector is characterized and compared to simulation results, proving a high accuracy level of the design and fabrication process, as well as excellent knowledge of the applied Schottky diodes. In a preliminary reliability assessment, the ACST low-barrier Schottky technology has proven very good stability without any diode failure during step stress tests, life tests, and environmental tests. The results demonstrate the suitability of the detector to be implemented in the 89 GHz receiver for the second European meteorological operational satellite programme (MetOp-SG).

Reconfigurable Vivaldi antenna array with integrated antipodal finline phase shifter with liquid crystal for W-Band applications

This paper presents a new finline phase shifter with an antipodal Vivaldi antenna. The structure offers the potential to be used in a wideband array configuration for electronic beam steering. The individual phase shift is realized by applying a DC voltage to liquid crystal inside the finline.