Inter-CubeSat Communication with V-band "Bull's eye" antenna

We present the study of a simple communication scenario between two CubeSats using a V-band “Bull's eye” antenna that we designed for this purpose. The return loss of the antenna has a -10dB bandwidth of 0.7 GHz and a gain of 15.4dBi at 60 GHz. Moreover, the low-profile shape makes it easily integrable in a CubeSat chassis. The communication scenario study shows that, using 0.01W VubiQ modules and V-band “Bull’s eye” antennas, CubeSats can efficiently transmit data within a 500 MHz bandwidth and with a 10-6 BER while being separated by up to 98m, under ideal conditions, or 50m under worst case operating conditions (5° pointing misalignment in E- and H-plane of the antenna, and 5° polarisation misalignment)

An internet of laboratory things

By creating “an Internet of Laboratory Things” we have built a blend of real and virtual laboratory spaces that enables students to gain practical skills necessary for their professional science and engineering careers. All our students are distance learners. This provides them by default with the proving ground needed to develop their skills in remotely operating equipment, and collaborating with peers despite not being co-located. Our laboratories accommodate state of the art research grade equipment, as well as large-class sets of off-the-shelf work stations and bespoke teaching apparatus. Distance to the student is no object and the facilities are open all hours. This approach is essential for STEM qualifications requiring development of practical skills, with higher efficiency and greater accessibility than achievable in a solely residential programme

Simplified model of interconnect layers under a spiral inductor

We demonstrate the feasibility of using effective medium theory to reduce the computational complexity of full-wave models of inductors that are placed over interconnects. Placing inductors over interconnects is one way that designers can tackle the problem of reducing overall chip size, however this has heretofore been a difficult option to evaluate because of the prohibitive memory requirements and run times for detailed simulations of the inductor. Here we replace the interconnects with a homogeneous equivalent layer that mimics their impact on the inductor to within 2% error, but reducing runtime and memory use by 90% or more

V-band Bull's eye antenna for multiple discretely steerable beams

We present a new approach to designing V-band Bull’s eye antenna so as to produce multiple beams, which are either fixed or discretely steerable. Bull’s eye antennas comprise concentric rings around a subwavelength aperture. Beam deflection is accomplished by adjusting the effective spacing of the rings, which we explain in terms of the coupling angle to free space and surface waves. We show that multiple beams can be obtained from a single antenna, with the deflection of each beam being controlled independently by the relevant portion of the ring pattern. We demonstrate the principle through rigorous full-wave simulations of two-beam antennas with symmetrical and asymmetrical shifts, and give experimental results for a prototype milled in aluminium, with two separate fixed beams each deflected 16° to either side of the broadside. We also propose means to obtain up to six different beam arrangements during operation by mechanically rotating a plate containing a special six-sector ring pattern. Our simulated example gives three patterns, a single broadside beam or two beams each deflected by 8° or 15°. The radiation efficiency of the antenna is 97%, and the gain of a single undeflected beam is 18.1dBi

Possibilities of Fabricating Copper-based RFID Tags with Photonic-sintered Inkjet Printing and Thermal Transfer Printing

This letter studies the possibilities of manufacturing copper-based passive UHF RFID tags using inkjet and thermal printing on two substrate materials, polyimide (Kapton) and a polyester based substrate (Flexcon THERMLfilm). Both printing methods are tested to fabricate different tag designs, and the performance of successfully printed tags is evaluated using wireless measurements. Measurement results show that both the printing methods, while using copper material, can be used to effectively fabricate passive UHF RFID tag antennas on selected substrates

A CubeSat for Calibrating Ground-Based and Sub-Orbital Millimeter-Wave Polarimeters (CalSat)

We describe a low-cost, open-access, CubeSat-based calibration instrument that is designed to support ground-based and sub-orbital experiments searching for various polarization signals in the cosmic microwave background (CMB). All modern CMB polarization experiments require a robust calibration program that will allow the effects of instrument-induced signals to be mitigated during data analysis. A bright, compact, and linearly polarized astrophysical source with polarization properties known to adequate precision does not exist. Therefore, we designed a space-based millimeter-wave calibration instrument, called CalSat, to serve as an open-access calibrator, and this paper describes the results of our design study. The calibration source on board CalSat is composed of five "tones" with one each at 47.1, 80.0, 140, 249 and 309 GHz. The five tones we chose are well matched to (i) the observation windows in the atmospheric transmittance spectra, (ii) the spectral bands commonly used in polarimeters by the CMB community, and (iii) The Amateur Satellite Service bands in the Table of Frequency Allocations used by the Federal Communications Commission. CalSat would be placed in a polar orbit allowing visibility from observatories in the Northern Hemisphere, such as Mauna Kea in Hawaii and Summit Station in Greenland, and the Southern Hemisphere, such as the Atacama Desert in Chile and the South Pole. CalSat also would be observable by balloon-borne instruments launched from a range of locations around the world. This global visibility makes CalSat the only source that can be observed by all terrestrial and sub-orbital observatories, thereby providing a universal standard that permits comparison between experiments using appreciably different measurement approaches

Linear angular momentum multiplexing-conceptualization and experimental evaluation with antenna arrays

Linear Angular Momentum Multiplexing is a new method for providing highly spectrally efficient short range communication between a transmitter and receiver, where one may move at speed transverse to the propagation. Such applications include rail, vehicle and hyperloop transport systems communicating with fixed infrastructure on the ground. This paper describes how the scientific concept of linear angular momentum multiplexing evolves from orbital angular momentum multiplexing. The essential parameters for implementing this concept are: a long array at least at one of the ends of the link; antenna element radiation characteristics; and the array element spacing relative to the propagation distance. These parameters are also backed by short range measurements carried out at 2.4GHz used to model the Rice fading channel and determine resilience to multipath fading