A CPW-fed antenna on 3D printed EBG substrate

This paper proposes a coplanar waveguide (CPW) fed antenna and electromagnetic band gap (EBG) structure on 3D printed substrates. Low-cost fuse filament fabrication (FFF) technology is employed. Two sets of experiments are described. In the first, the antenna and EBG patterns are etched on copper clad Mylar® polyester film and attached to the 3D printed substrates. In the second, the patterns of the EBG are added using silver conductive paint. Both experiments compare very well between them, and with the simulations. The EBG structure provides improved antenna performance such as gain, efficiency and directivity. The antenna and EBG are designed for the 2.4 GHz Bluetooth frequency band. The Finite-difference time-domain (FDTD) computational method was used for the study

MIMO LTE Vehicular Antennas on 3D Printed Cylindrical Forms

A multi-band antenna suitable for Long-term Evolution (LTE) is shaped around a 3D printed cylindrical form, and arranged in a MIMO configuration. The antenna is based on a planar wideband monopole radiator with an additional resonator for the LTE700 frequency band. Conforming the antenna onto a cylindrical shape reduces its length while keeping performance. It also reduces the space used by the MIMO antenna system. Furthermore, the plastic cylinder improves the mechanical strength of the supporting substrate for the radiating element. The aim is to study the potential of additive manufacturing (AM) of substrates for the development of conformal vehicular antenna. Two antennas have been fabricated, one etched on a copper clad Mylar substrate, and a second painted directly onto the cylindrical form. The two antennas have been measured and the results are compared. Two copper based antennas have been tested in a MIMO configuration. The antennas successfully operate at all LTE and mobile frequency bands. Finite different time domain simulations compare well with measurements

UWB antenna on 3D printed flexible substrate and foot phantom

An ultra-wideband (UWB) monopole antenna on an additive manufactured (AM) flexible substrate for foot wear application is proposed. The 3D printing of foot phantoms for the testing of this type of antennas is also introduced. Inexpensive fuse filament fabrication (FFF) technology is utilized for these developments. Flexible polylactic acid plastic filament (PLA) material is used for the antenna while transparent PLA for the phantom. The antenna is intended for integration into the footwear tongue. The UWB monopole antenna achieves -10dB input impedance matching from 3.1GHz to over 10.6GHz in freespace, on the foot phantom and on the real human body. Simulation and measurement confirm the ultra-wideband operation of the antenna

Inkjet printed and folded LTE antenna for vehicular application

A multi-band antenna suitable for Long-term Evolution (LTE) is inkjet-printed, and then folded around a cylindrical form. The plastic cylinder is also printed using additive manufacturing techniques, as a separate process. The antenna is based on a planar wideband monopole radiator concept with an additional resonator for the LTE700 frequency band. The aim is to study the potential of low-cost additive manufacturing (AM) techniques for the development of vehicular antennas. Two antennas have been fabricated, one on paper substrate, and a second on polyethylene terephthalate (PET) substrate. The one on paper is tested as a planar monopole antenna on a large ground plane. The one printed on PET is shaped onto the cylindrical form. The main aim is to investigate the use of low-cost inkjet printing techniques for the fabrication of disposable vehicular antennas that can be upgraded regularly. The antennas successfully operate at all LTE and mobile frequency bands. Finite different time domain simulations compare well with measurements

Inkjet printed dual band antenna for paper UAVs

A dual band antenna is inkjet-printed and then folded as part of a paper unmanned aerial vehicle (UAV). The patterns of the antenna are reproduced on a standard photo paper substrate using an off the shelf inkjet printer. Readily available cartridges with nanoparticle silver conductive ink are employed. A single-layer planar antenna is fed by coplanar waveguide (CPW). The geometry of the radiating element consists of a semicircle with a centered square slot. In order to examine the effect of bending on performance, the antenna is tested unfolded and then folded when integrated onto the airplane. Two configurations of the folded antenna on the plane are analyzed. The aim is to investigate the feasibility of fabricating foldable antennas for paper airplanes using low-cost inkjet printing techniques. The antenna operates at the existing 2.4 GHz and 5.2 GHz WLAN bands. Finite different time domain simulations compare well with measurement

Evaluation of a low-cost inkjet printed slot antenna for energy harvesting applications

A circularly polarized patch antenna fabricated using commercially available, low-cost, printers is described. Two additive processes are combined for the fabrication: stereolithography (SLA) and inkjet printing of silver inks. A widely available SLA 3D printer is employed to fabricate the substrate of the antenna. Inkjet printing is used to deposit the metallic layers of the radiating element on the substrate. The two machines employed are very low-cost in comparison to those used in previously reported work. Good adhesion of the metallic patterns to the substrates is observed. Furthermore, the resistance of the added metallic patch is relatively low. The aim is to demonstrate the use of alternative, inexpensive machines, for the prototyping and manufacturing of antennas on 3D printed substrates. In this work, the antenna operates at the 1.575GHz GPS frequency band. Finite-difference-time-domain simulations compare well with the practical experiments

Liquids sensor/detector using an EBG structure

This paper describes a novel procedure to detect liquids with various permittivities using an electromagnetic band gap (EBG) structure. The concept can also be used as a method to achieve antenna frequency tunability. The main sensor consists of an array of square patches on a square unit cell with a series of cuts and grooves in the dielectric material between the patches. These trenches allow for the deposition of the liquids to be detected. The variation in the dielectric characteristics of the liquids inserted produces a change in the reflected phase of the EBG. This change in phase could be detected in various ways. In this paper, a planar antenna has been placed at a short distance from the EBG structure. The changes in the phase in the surface waves produce a change in the reflection coefficient of the antenna. Butan-1-ol, propan-2-ol, ethanol and methanol have been inserted to demonstrate the tuning technique. In order to complete the experiments the reflection coefficients and the radiation patterns were measured. Good agreement has been found between simulated and measured results. The envisaged detector could be used in a laboratory or clean room where liquids may fall into the channels

Dynamics of quantum trajectories in chaotic systems

Quantum trajectories defined in the de Broglie--Bohm theory provide a causal way to interpret physical phenomena. In this Letter, we use this formalism to analyze the short time dynamics induced by unstable periodic orbits in a classically chaotic system, a situation in which scars are known to play a very important role. We find that the topologies of the quantum orbits are much more complicated than that of the scarring and associated periodic orbits, since the former have quantum interference built in. Thus scar wave functions are necessary to analyze the corresponding dynamics. Moreover, these topologies imply different return routes to the vicinity of the initial positions, and this reflects in the existence of different contributions in each peak of the survival probability function.Comment: 7 pages, 4 figures. Accepted for publication in Europhysics Letter

Inkjet printed GPS antenna on a 3D printed substrate using low-cost machines

Additive manufacturing (AM), also known as 3D printing, is a process of fabricating a 3D digital design by printing layer after layer. 3D printing has advanced very rapidly in recent years and has become an alternative to traditional manufacture methods for customized objects. Originally intended for the prototyping of mechanical objects, this technique has expanded into different areas such as biomedical [1] and electronics [2]. Within electronics, antennas and microwave engineering can greatly benefit from this technology. Researchers have already demonstrated the potential applicability of 3D printing in this field. Light weight waveguides have been fabricated by copper plating plastics forms [3]. Substrates for antenna applications have been modified and new properties have been found with the assistance of additive manufacturing [4]. Novel frequency selective structures (FSS) have been developed by fully [5] and partially [6] metalizing 3D printed elements. Non-uniform electromagnetic band gap structures have been fabricated on printed substrates [7]. Antennas have been placed onto wearables and tested on 3D printed phantoms [8]–[9]. Fig. 1

Anaplasmosis outbreak in lambs: First report causing carcass condemnation

In spring and summer 2020, six outbreaks of condemnation of jaundiced lamb carcasses were diagnosed in different farms in Aragón region, Spain. Anaplasma ovis was identified in all affected farms. Four hundred and ninety-two lambs from two affected farms were more closely examined. Clinical examination, haematologies, biochemistries, histopathology and microbiological and molecular analyses were performed. After slaughter, 34.84% of the lambs showed jaundiced carcasses and 79.64% presented splenomegaly at the abattoir. All tested lambs with icteric carcasses showed positive A. ovis PCR, although 72.72% of the unaffected lambs also tested positive. However, the bacterial load was significantly higher in the animals that showed jaundiced carcasses (Cq: 25.00 vs 26.16; p = 0.004). Moreover, all the tested lambs that showed severe anaemia were PCR positive. On the contrary, the PCR negative lambs did not show anaemia. Lambs that presented icteric carcasses displayed severe regenerative anaemia with significantly lower erythrocyte count (7.18 vs. 11.97), haematocrit (26.89 vs. 34.82) and haemoglobin (8.50 vs. 11.10) than unaffected lambs. Reticulocyte count (18.80 vs. 5.65) was also significantly increased in affected animals. This article describes a new disorder caused by Anaplasma ovis that is producing significant economic losses associated with the carcass condemnation of apparently healthy lamb