Background: The purpose of this study was to determine if 3D printed lenses with wavelength specific anti-reflective (AR) surface structures would improve beam intensity and thus radar efficiency for a Printed Circuit Board (PCB)-based 60 GHz radar. This would have potential for improved low-cost radar lenses for the consumer product market. Methods: A hyperbolic lens was designed in 3D Computer Aided Design (CAD) software and was then modified with a wavelength specified AR structure. Electromagnetic computer simulation was performed on both the ‘smooth’ and ‘AR structure’ lenses and compared to actual 60 GHz radar measurements of 3D printed polylactic acid (PLA) lenses. Results: The simulation results showed an increase of 10% in signal intensity of the AR structure lens over the smooth lens. Actual measurement showed an 8% increase in signal of the AR structure lens over the smooth lens. Conclusions: Low cost and readily available Fused Filament Fabrication (FFF) 3D printing has been shown to be capable of printing an AR structure coated hyperbolic lens for millimeter wavelength radar applications. These 3D Printed AR structure lenses are effective in improving radar measurements over non-AR structure lenses.

This paper describes an iterative approach to determine quasi-optical properties of standard 3D printer filament material to, in an inexpensive and fast way, construct focusing lenses for millimetre wave systems. Results from three lenses with different focal lengths are shown and discussed. The real part of the permittivity at 60GHz for polylactic acid (PLA) is in this paper determined to be ε_r=2.74. © 2018 Institution of Engineering and Technology. All rights reserved.

There is an increased interest in contact-less vital sign monitoring methods as they offer higher flexibility to the individual being observed. Recent industrial development enabled radar functionality to be packed in single-chip solutions, decreasing application complexity and speeding up designs. Within this paper, a vital sign radar has been developed utilizing a recently released 60GHz frequency modulated continuous wave single-chip radar in combination with 3D-printed quasi-optics. The electronics development has been focused on compactness and high system integration using a low cost design process. The final experiments prove that the radar is capable of tracking human respiration rate and heartbeat at the same time from a distance of 1m.

With the advent of Internet of Things (IoT) it has become clear that radio-frequency (RF) designers have to be aware of power constraints, e.g., in the design of simplistic ultra-low power receivers often used as wake-up radios (WuRs). The objective of this work, one of the first systematic studies of power bounds for RF-systems, is to provide an overview and intuitive feel for how power consumption and sensitivity relates for low-power receivers. This was done by setting up basic circuit schematics for different radio receiver architectures to find analytical expressions for their output signal-to-noise ratio including power consumption, bandwidth, sensitivity, and carrier frequency. The analytical expressions and optimizations of the circuits give us relations between dc-energy-per-bit and receiver sensitivity, which can be compared to recent published low-power receivers. The parameter set used in the analysis is meant to reflect typical values for an integrated 90 nm complementary metal-oxide-semiconductor fabrication processes, and typical small sized RF lumped components.

An ultra-low power wake-up radio receiver using no oscillators is described. The radio utilizes an envelope detector followed by a baseband amplifier and is fabricated in a 130-nm complementary metal-oxide-semiconductor process. The receiver is preceded by a passive radio-frequency voltage transformer, also providing 50 Omega antenna matching, fabricated as transmission lines on the FR4 chip carrier. A sensitivity of -47 dBm with 200 kb/s on-off keying modulation is measured at a current consumption of 2.3 mu A from a 1 V supply. No trimming is used. The receiver accepts a dBm continuous wave blocking signal, or modulated blockers 6 dB below the sensitivity limit, with no loss of sensitivity.

An anti-counterfeit and authentication method usingtime controlled numeric tokens enabling a secure logistic chain ispresented. Implementation of the method is illustrated with apharmaceutical anti-counterfeit system. The method uses activeRFID technology in combination with product seal. Authenticityis verified by comparing time controlled ID-codes, i.e. numerictokens, stored in RFID tags and by identical numeric tokensstored in a secure database. The pharmaceutical products areprotected from the supplier to the pharmacist, with thepossibility to extend the authentication out to the end customer.The ability of the method is analyzed by discussion of severalpossible scenarios. It is shown that an accuracy of 99.9% tellingthe customer she has an authentic product is achieved by the useof 11-bit ID-code strings.

This paper presents analytical expressions for the sensitivity of a low power envelope detector driven by a weak RF signal in the presence of a blocking signal. The envelope detector has been proposed for low power Wake-Up radios in applications such as RFID and wireless sensor systems. The theoretical results are verified with simulations of a modern short channel MOS transistor in a commonly used circuit topology. A discussion around a tutorial example of a radio frontend, consisting of an LNA and a detector, is presented. It is shown that the sensitivity of a low power envelope detector can reach -62 dBm with a low power LNA and in presence of a CW blocker. © 2011 IEEE.

In this paper we present a novel active radio frequency identification system consisting of transponders with low complexity, low power consumption, and long system reading range. The transponder’s low complexity and small circuit integration area indicate that the production cost is comparable to the one of a passive tag. The hardware keystone is the transponder’s radio wake-up transceiver, which is a single oscillator with very low power consumption. The communication protocol, based on frequency signalling binary tree, contributes to the low complexity of the tag architecture. More than 1500 tags can be read per second. The average transponder ID read-out delay is 319 ms when there are 1000 transponders within reach of the interrogator. The calculated expected life time for a transponder is estimated to be almost three years.

A novel radio receiver circuit, functioning as a tuned active, detecting antenna, is described. The receiver is suggested to be part of a new radio system with the potential of competing with the range capability of active RFID-tags and, through its low power and long lifetime, with passive RFID-tags. The circuit is outlined and the functionality is verified by simulations and measurements.

A 24 MHz discrete prototype showed better than -70 dBm sensitivity and 5 kHz bandwidth, with a power consumption of 102 μW. Simulations of a monolithic implementation were performed at 2.5 GHz. The detector is modeled by using 180 nm CMOS transistors. In simulations the power consumption for the detector is below 125 μW at a sensitivity of -83 dBm and a bandwidth of 9 MHz.

Our conclusion is that this novel simple circuit architecture is well suited for monolithic implementation of a low power transceiver.

There are many known technologies that can be used to monitor surfaces, but the most of them requires a transparent environment to be functional. In the Blast Furnace where the environment is full of dust and fume at high temperatures those technologies are not applicable.

With a functional technology in such an environment the burden surface could be analysed and monitored, which in its extension would lead to a way to control the charging operation in the BF and thus a better use of raw material and also a better gas utilization.

In this paper we will discuss the use of microwave technology as one technology with the potential to create a topographical image of the burden surface in the Blast Furnace during operation.