Johanna Hanning

Development of a 557 GHz GaAs monolithic membrane-diode mixer

We present the development of a monolithically integrated 557 GHz membrane Schottky diode mixer. RF test shows state-of-the-art performance with an optimum receiver noise temperature below 1300 K DSB and an estimated mixer DSB conversion loss of 9 dB and a mixer DSB noise temperature of 1100 K including all losses.

Monolithic HBV-Based 282-GHz Tripler With 31-mW Output Power

We present a heterostructure barrier varactor multiplier at 282 GHz. The tripler chip was monolithically fabricated in the InGaAs/InAlAs material system on InP as carrier substrate and mounted in a fix-tuned waveguide block. Standard rectangular waveguides WR-10/WR-3 connect the multiplier chip to the respective input/output of the waveguide block. Measurements produced 31 mW of output power and a minimum conversion loss of 11.6 dB (7% efficiency). The device dimensions and their electrical and thermal influences are also presented.

Molecular Spectroscopy With a Compact 557-GHz Heterodyne Receiver

We report on a heterodyne terahertz spectrometer based on a fully integrated 557-GHz receiver and a digital fast Fourier transform spectrometer. The receiver consists of a chain of multipliers and power amplifiers, followed by a heterostructure barrier varactor tripler that subharmonically pumps a membrane GaAs Schottky diode mixer. All sub-components are newly developed and optimized with regard to the overall receiver performance such as noise temperature, power consumption, weight and physical size. The receiver works at room temperature, has a double sideband noise temperature as low as 2000 K at a maximum power consumption of 4.5 W with an Allan time of 10 s and a sideband gain ratio of 0.52. The performance of the spectrometer is demonstrated by absorption spectroscopy of H2O and CH3OH with an instantaneous bandwidth of 1.5 GHz and a resolution of 183 kHz. Several pressure broadening parameters of methanol absorption lines were determined, that agree with other published data. Using the experimentally determined molecular parameters the CH3OH absorption spectrum could be modeled with very high precision.

Single-Flange 2-Port TRL Calibration for Accurate THz S-Parameter Measurements of Waveguide Integrated Circuits

This paper describes a single flange 2-port measurement setup for S-parameter characterization of waveguide integrated devices. The setup greatly reduces calibration and measurement uncertainty by eliminating vector network analyzer (VNA) extender cable movement and minimizing the effect of waveguide manufacturing tolerances. Change time of standards is also improved, reducing the influence of VNA drift on the uncertainty. A TRL calibration kit has been manufactured and measurements are demonstrated in WR-03 (220-325 GHz).

Integrated terahertz electronics for imaging and sensing

We present the development of integrated submillimeter wave receivers and transmitters based on Schottky- and HBV-diode technology at Chalmers University of technology.

A broadband THz waveguide-to-suspended stripline loop-probe transition

We present a novel waveguide-to-suspended stripline loop-probe transition operating over the entire WR-1.0 waveguide band. The loop probe is designed for broadband response with simulated RL > 15 dB, and has an integrated DC return path, which can also be extended for biasing. The measured insertion loss for a back-to-back configuration is 1–2 dB in almost the entire frequency range of 750–1100 GHz.