13 research outputs found
Space- and time-resolved Seebeck and Nernst voltages in laser-heated permalloy/gold microstructures
Thermoelectric effects in microstructured permalloy (Py) / gold (Au) wires are investigated using spatially and time-resolved measurements based on scanning focused laser heating. Supported by numerical simulations of the temperature distribution, we identify two major contributions to the laser-induced signals: (i) the Seebeck effect due to thermocouples of Py/Au and (ii) the anomalous Nernst effect (ANE) in Py with a coefficient of NANE 0:5 V/K. ANE-based magnetic imaging of magnetic domains and magnetization reversal is demonstrated with a lateral resolution on the m-scale
High performance WR-1.5 corrugated horn based on stacked rings
We present the development and characterisation of a high frequency (500-750
GHz) corrugated horn based on stacked rings. A previous horn design, based on a
Winston profile, has been adapted for the purpose of this manufacturing process
without noticeable RF degradation. A subset of experimental results obtained
using a vector network analyser are presented and compared to the predicted
performance. These first results demonstrate that this technology is suitable
for most commercial applications and also astronomical receivers in need of
horn arrays at high frequencies.Comment: 9 page
Monolithic Metal-Coated Plastic Components for mm-Wave Applications
A stereolithography-based manufacturing process for monolithic high aspect ratio components for mm-wave and sub-mm-wave applications is demonstrated. A 25mm long straight waveguide and a diagonal horn antenna, both for the WR-3.4 band (220–330 GHz), are manufactured and characterized. The waveguide is found to exhibit transmission losses close to the theoretical minimum for Cu, and the performance of the diagonal antenna in terms of cross-polarization and directivity matches closely a metallic split-block reference antenna. These results confirm the high surface quality and mechanical accuracy of the employed 3D printing and plating techniques and thus validate the process for rapid manufacturing of monolithic components up to 330 GHz
Phase imaging with intermodulation atomic force microscopy
Intermodulation atomic force microscopy (IMAFM) is a dynamic mode of atomic
force microscopy (AFM) with two-tone excitation. The oscillating AFM cantilever
in close proximity to a surface experiences the nonlinear tip-sample force
which mixes the drive tones and generates new frequency components in the
cantilever response known as intermodulation products (IMPs). We present a
procedure for extracting the phase at each IMP and demonstrate phase images
made by recording this phase while scanning. Amplitude and phase images at
intermodulation frequencies exhibit enhanced topographic and material contrast.Comment: 6 pages, 6 page
Rectangular to Large Diameter Conical Corrugated Waveguide Converter Based on Stacked Rings
This paper considers the design and manufacture, using stacked rings, of a standard corrugated antenna for the WM-380 band for use as a converter from a WM-380 rectangular aperture to a large diameter conical corrugated waveguide. In-house mode matching software is utilised for the design and three prototypes manufactured using stacked rings. The level of agreement of the stacked ring prototypes with the design predictions for the return loss and HE11 modal coupling is measured and found to demonstrate high levels of agreement
Rectangular to Large Diameter Conical Corrugated Waveguide Converter Based on Stacked Rings
This paper considers the design and manufacture, using stacked rings, of a standard corrugated antenna for the WM-380 band for use as a converter from a WM-380 rectangular aperture to a large diameter conical corrugated waveguide. In-house mode matching software is utilised for the design and three prototypes manufactured using stacked rings. The level of agreement of the stacked ring prototypes with the design predictions for the return loss and HE11 modal coupling is measured and found to demonstrate high levels of agreement