scholarly journals Energy-Efficient Harmonic Transponder Based on On-Off Keying Modulation for Both Identification and Sensing

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 620
Author(s):  
Valentina Palazzi ◽  
Luca Roselli ◽  
Manos M. Tentzeris ◽  
Paolo Mezzanotte ◽  
Federico Alimenti

This paper presents a novel passive Schottky-diode frequency doubler equipped with an on-off keying (OOK) modulation port to be used in harmonic transponders for both identification and sensing applications. The amplitude modulation of the second-harmonic output signal is achieved by driving a low-frequency MOSFET, which modifies the dc impedance termination of the doubler. Since the modulation signal is applied to the gate port of the transistor, no static current is drained. A proof-of-concept prototype was manufactured and tested, operating at 1.04 GHz. An on/off ratio of 23 dB was observed in the conversion loss of the doubler for an available input power of −10 dBm. The modulation port of the circuit was excited with a square wave (fm up to 15 MHz), and the measured sidebands in the spectrum featured a good agreement with the theory. Then, the doubler was connected to a harmonic antenna system and tested in a wireless experiment for fm up to 1 MHz, showing an excellent performance. Finally, an experiment was conducted where the output signal of the doubler was modulated by a reed switch used to measure the rotational speed of an electrical motor. This work opens the door to a new class of frequency doublers, suitable for ultra low-power harmonic transponders for identification and sensing applications.

Sensors ◽  
2019 ◽  
Vol 19 (4) ◽  
pp. 853 ◽  
Author(s):  
Junran Xu ◽  
Chung Leung ◽  
Xin Zhuang ◽  
Jiefang Li ◽  
Shubhendu Bhardwaj ◽  
...  

Magneto-elasto-electric (ME) coupling heterostructures, consisting of piezoelectric layers bonded to magnetostrictive ones, provide for a new class of electromagnetic emitter materials on which a portable (area ~ 16 cm2) very low frequency (VLF) transmitter technology could be developed. The proposed ME transmitter functions as follows: (a) a piezoelectric layer is first driven by alternating current AC electric voltage at its electromechanical resonance (EMR) frequency, (b) subsequently, this EMR excites the magnetostrictive layers, giving rise to magnetization change, (c) in turn, the magnetization oscillations result in oscillating magnetic fields. By Maxwell’s equations, a corresponding electric field, is also generated, leading to electromagnetic field propagation. Our hybrid piezoelectric-magnetostrictive transformer can take an input electric voltage that may include modulation-signal over a carrier frequency and transmit via oscillating magnetic field or flux change. The prototype measurements reveal a magnetic dipole like near field, demonstrating its transmission capabilities. Furthermore, the developed prototype showed a 104 times higher efficiency over a small-circular loop of the same area, exhibiting its superiority over the class of traditional small antennas.


2021 ◽  
Vol 11 (15) ◽  
pp. 7122
Author(s):  
Simona Mosca ◽  
Tobias Hansson ◽  
Maria Parisi

Optical frequency comb synthesizers with a wide spectral range are an essential tool for many research areas such as spectroscopy, precision metrology, optical communication, and sensing. Recent studies have demonstrated the direct generation of frequency combs, via second-order processes, that are centered on two different spectral regions separated by an octave. Here, we present the capability of optical quadratic frequency combs for broad-bandwidth spectral emission in unexplored regimes. We consider comb formation under phase-matched conditions in a continuous-wave pumped singly resonant second-harmonic cavity, with large intracavity power and control of the detuning over several cavity line widths. The spectral analysis reveals quite distinctive sidebands that arise far away from the pump, singularly or in a mixed regime together with narrowband frequency combs. Notably, by increasing the input power, the optical frequency lines evolve into widely spaced frequency clusters, and at maximum power, they appear in a wavelength range spanning up to 100 nm. The obtained results demonstrate the power of second-order nonlinearities for direct comb production within a wide range of pump wavelengths.


1995 ◽  
Vol 413 ◽  
Author(s):  
G. I. Stegeman ◽  
M. JÄger ◽  
A. Otomo ◽  
W. Brinker ◽  
S. Yilmaz ◽  
...  

ABSTRACTThe phenomenon of second harmonic generation has been studied from the earliest days of nonlinear optics.[l] To date the most impressive results in terms of conversion efficiency for as low an input power as possible have been obtained in channel waveguides made from inorganic materials.[2] However, when their second order nonlinearities (10s of pm/V) are compared with those of organic materials (10s → 100s pmn/V), it is clear that organic materials should eventually produce much better harmonic conversion efficiencies. [3]


2014 ◽  
Vol 668-669 ◽  
pp. 808-811
Author(s):  
Hui Min Zhang ◽  
Qing Ping Wu ◽  
Zheng Yuan Zhou ◽  
Xun Wang

The low frequency voltage controlled oscillator (VCO) is designed using integrated operational amplifier. The frequency of the output signal of VCO changes with the magnitude of the input signal voltage, and show a linear relationship within a certain range through the experimental test. Experiments show that, under the input of certain amplitude and frequency range of the square wave, triangle wave, saw-tooth wave, the output waveform of VCO respectively is ambulance, fire siren and other kinds of ambulance siren Signal. This innovative design’ cost is low, realized by analog circuit. It can be used in the practice of teaching case, electronic production or development of sound panels.


Circuit World ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Guoda Wang ◽  
Ping Li ◽  
Yumei Wen ◽  
Zhichun Luo

Purpose Existing control circuits for piezoelectric energy harvesting (PEH) suffers from long startup time or high power consumption. This paper aims to design an ultra-low power control circuit that can harvest weak ambient vibrational energy on the order of several microwatts to power heavy loads such as wireless sensors. Design/methodology/approach A self-powered control circuit is proposed, functioning for very brief periods at the maximum power point, resulting in a low duty cycle. The circuit can start to function at low input power thresholds and can promptly achieve optimal operating conditions when cold-starting. The circuit is designed to be able to operate without stable DC power supply and powered by the piezoelectric transducers. Findings When using the series-synchronized switch harvesting on inductor circuit with a large 1 mF energy storage capacitor, the proposed circuit can perform 322% better than the standard energy harvesting circuit in terms of energy harvested. This control circuit can also achieve an ultra-low consumption of 0.3 µW, as well as capable of cold-starting with input power as low as 5.78 µW. Originality/value The intermittent control strategy proposed in this paper can drastically reduce power consumption of the control circuit. Without dedicated cold-start modules and DC auxiliary supply, the circuit can achieve optimal efficiency within one input cycle, if the input signal is larger than voltage threshold. The proposed control strategy is especially favorable for harvesting energy from natural vibrations and can be a promising solution for other PEH circuits as well.


2015 ◽  
Vol 644 ◽  
pp. 236-239 ◽  
Author(s):  
Xin Zhuang ◽  
Marc Lam Chok Sing ◽  
Christophe Dolabdjian ◽  
Y. Wang ◽  
P. Finkel ◽  
...  

The intermediated strain can convert a magnetic field to an electric output signal in a magnetostrictive-piezoelectric layered composite via three parameters: the magnetoelastic coupling, the piezoelastic coupling and the mechanical impedance. These three parameters are dominated respectively by the magnetostrictive coefficient, the piezoelectric coefficient and the mean flexibility of material in the composite. Focusing on these three parameters, many investigations on the ME enhancement have been carried out by choosing the correct material or by adjusting the ratio between the two phases in the composite [4]. Thereafter, the noise performance of ME laminates has been studied for applications as a magnetic sensor. In the last several years, the intrinsic noise sources for both the composite and the amplifier circuit have been mathematically modeled and experimentally characterized. The passively sensed signal can be amplified by either a voltage or a charge method. Furthermore, the noise contributions from the detection electronics were also integrated in the noise performance analysis [5]. According to these studies, dielectric dissipation in the piezoelectric phase is the main contribution to the noise floor for low-frequency magnetic field sensing even though the equivalent current noise source from the electronics induce fluctuations in the output signal of the low-frequency charge detection as well [6].


Author(s):  
Sourav Paul ◽  
Provas Kumar Roy

Low frequency oscillation has been a major threat in large interconnected power system. These low frequency oscillations curtain the power transfer capability of the line. Power system stabilizer (PSS) helps in diminishing these low frequency oscillations by providing auxiliary control signal to the generator excitation input, thereby restoring stability of the system. In this chapter, the authors have incorporated the concept of oppositional based learning (OBL) along with differential search algorithm (DSA) to solve PSS problem. The proposed technique has been implemented on both single input and dual input PSS, and comparative study has been done to show the supremacy of the proposed techniques. The convergence characteristics as well authenticate the sovereignty of the considered algorithms.


2020 ◽  
Vol 10 (20) ◽  
pp. 7080
Author(s):  
Ji Xia ◽  
Qifeng Qiao ◽  
Guangcan Zhou ◽  
Fook Siong Chau ◽  
Guangya Zhou

A new class of hybrid systems that couple optical and mechanical nanoscale devices is under development. According to their interaction concepts, two groups of opto-mechanical systems are summarized as mechanically tunable and radiation pressure-driven optical resonators. On account of their high-quality factors and small mode volumes as well as good on-chip integrability with waveguides/circuits, photonic crystal (PhC) cavities have attracted great attention in sensing applications. Benefitting from the opto-mechanical interaction, a PhC cavity integrated opto-mechanical system provides an attractive platform for ultrasensitive sensors to detect displacement, mass, force, and acceleration. In this review, we introduce basic physical concepts of opto-mechanical PhC system and describe typical experimental systems for sensing applications. Opto-mechanical interaction-based PhC cavities offer unprecedented opportunities to develop lab-on-a-chip devices and witness a promising prospect to further manipulate light propagation in the nanophotonics.


2010 ◽  
Vol 29-32 ◽  
pp. 884-889
Author(s):  
Hua Wei Zhan ◽  
Cai Xia Guo ◽  
Yu Zhang ◽  
Yun Zhou

Multimode feed network is an important part of shortwave multimode multifeed antenna system. The design of feed network is a pivotal technique in the process of projecting antenna system. The substructure analyzing method of interconnect-net is based on the substructure matrix database which is formed by converting the net parameters into data. And it characterizes the non-uniform net units through the database directly. Then cascades the known database of the net units by means of ordinary net cascade method, thus performing optimization in the net. In the paper, the Substructure Analyzing Method of Interconnect-net is applied to designing multi-mode multi-feed network, a typical example of multi-mode multi-feed network optimization is given to illustrate the efficiency of the method.


Author(s):  
F. Tateo ◽  
M. Collet ◽  
M. Ouisse ◽  
M. N. Ichchou ◽  
K. A. Cunefare

In the last few decades, researchers have given a lot of attention to new engineered materials with the purpose of developing new technologies and devices such as mechanical filters, low frequency sound and vibration isolators, and acoustic waveguides. For instance, elastic phononic crystals may come to mind. They are materials with elastic or fluid inclusions inside a matrix made of an elastic solid. The anomalous behavior in phononic crystals arises from interference of waves propagating within an inhomogeneous material. The inclusions inside the matrix cause strong modifications of scattering properties. However, the application of phononic crystals is still limited to sonic frequencies. In fact, band gaps can be generated only when the acoustic wavelength is comparable to the distance between the inclusion. In order to overcome this limitation, a new class of metamaterial has been proposed: meta composite. This new class of material can modify the dynamics of the underlying structure using a bidimensional array of electromechanical transducers, which are composed by piezo patches connected to a synthetic negative capacitance. In this study, an application of the Floquet-Bloch theorem for vibroacoustic power flow optimization will be presented. In the context of periodically distributed, damped 2D mechanical systems, this numerical approach allows one to compute the multimodal waves dispersion curves into the entire first Brillouin zone. This approach also permits optimization of the piezoelectric shunting electrical impedance, which controls energy diffusion into the proposed semiactive distributed set of cells. Experiments performed on the examined structure illustrates the effectiveness of the proposed control method. The experiment requires a rectangular metallic plate equipped with seventyfive piezopatches, controlled independently by electronic circuits. More specifically, the out-of-plane displacements and the averaged kinetic energy of the controlled plate are compared in two different cases (control system on/off). The resulting data clearly show how this proposed technique is able to dampen and selectively reflect the incident waves.


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