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- 实验方案
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A dual-band efficient circularly polarized rectenna for RF energy harvesting systems
摘要： A multilayered circularly polarized (CP), dual-band, stacked slit-/slotted-patch antenna with compact size and with compact rectifier is offered for RF energy harvesting systems. The compact dual-band CP antenna size is able to achieve by stacking slotted-circular-patch (SCP) on the substrate above the tapered-slit-octagon patch (TSOP). Dual-band CP radiation is realized by stacking the SCP on the TSOP and the microstrip feedline with metallic-via to SCP. Eight-tapered-slit with length difference of 6.25% are embedded along the octagonal directions symmetrically on the TSOP from the patch's center and two unequal size circular slots are embedded in diagonal axis onto SCP to produce dual-orthogonal modes with almost equal magnitude for CP waves. The designed antenna is realized measured gain of greater than 5.2 dBic across the band (0.908-0.922 GHz) with maximum gain of 5.41 dBic at 0.918 GHz and gain of greater than 6.14 dBic across the band (2.35-2.50 GHz) with maximum gain of 7.94 dBic at 2.485 GHz. An overall antenna volume is 0.36λo × 0.36λo × 0.026λo (λo is free space wavelength at 0.9 GHz). A compact composite right-/left-handed (CRLH) based rectifier with dual-band at 0.9 and 2.45 GHz is designed, prototyped, and measured. The right-handed (RH) part of the CRLH transmission line (TL) is formed by a microstrip line. The left-handed (LH) part of the CRLH-TL is formed by lumped components. The measured RF-DC conversion efficiency is 43% at 0.9 GHz and 39% at 2.45 GHz with rectifier size of 0.18λo × 0.075λo × 0.0002λo at 0.9 GHz.
关键词： slotted-patch,stacked antenna,energy harvesting,rectenna,rectifier,circular polarization,dual-band
更新于2025-09-23 15:23:52
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A passive SPICE model for rectennas
摘要： Purpose – This paper aims to present a SPICE model to represent antennas in receiving mode. The model can be used to evaluate the performance of the antenna when it is coupled to several different nonlinear electric circuits. The proposed methodology is particularly suitable for rectenna applications, as it allows the analysis of different configurations for a rectenna more efficiently than using full-wave analysis simulators coupled directly to each rectifier circuit. Design/methodology/approach – The model presented uses reciprocity theory to calculate the ideal voltage source of the Thevenin-equivalent circuit for an antenna. Vector fitting is then used to approximate the model to rational functions that can be converted to Resistor, Inductor and Capacitor circuits. Additional components are added to the circuit to prevent numerical instability. Findings – Two rectennas are used to illustrate the performance of the proposed model, one based on a 2.45-GHz rectangular patch antenna and another based on a planar spiral antenna. The second antenna has impedance with positive and negative real parts along the frequency range, which could lead to numerical instabilities. The proposed method is shown to be stable while working with these negative resistance values, which may appear during circuit parameterization. Research limitations/implications – The equivalent SPICE circuit model for the antenna makes it easy to simulate nonlinear circuits connected to the antenna and perform transient analyses. The computational cost of antenna analysis is reduced, being more computationally efficient than methods that involve full-wave simulation. This characteristic makes it an interesting approach for working with rectennas, or any application where the time constant of the circuit is much longer than the period of the incident wave. Originality/value – For most antenna applications, the numerical stability of the circuit can be achieved using passive enforcement. However, depending on the phase response of the antenna, the impedance that represents its far-field characteristic may present a negative real part, in which case, passive enforcement will fail. In this paper, the problem of numerical instability is solved by introducing an offset resistance and a current-controlled voltage source to the model.
关键词： Antenna,SPICE model,Rectenna,Energy harvesting
更新于2025-09-23 15:23:52
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[IEEE 2018 AEIT International Annual Conference - Bari, Italy (2018.10.3-2018.10.5)] 2018 AEIT International Annual Conference - Solid State Rectifier as Terahertz Detector
摘要： We present a new solid state rectifier, compatible with CMOS integrated circuit, suitable to direct conversion of terahertz radiation, at room temperature. The structure creates a rectenna, consists in a truncated conical helix extruded from a planar spiral and connected to a nanometric metallic whisker at one of its edges. The whisker reaches the gate of a MOS-FET transistor. Rectification can be obtained by the self-mixing effect occurring into the plasma waves generate underneath the gate. The proposed solution is easy to integrate with existing imaging systems. No need of scaling toward very scaled and costly technological node is required, since the plasma wave are not dependent on the gate extension. The remaining electronics should only provide the necessary integrated readout. A theoretical explanation of the self-mixing process, and TCAD simulations showing the onset of the DC potential are presented. An additional detector structure, the double barrier rectifier, is also presented for comparison.
关键词： MOS-FET,rectifying antenna (rectenna),Image detector,CMOS,THz antennas
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Auckland (2018.8.5-2018.8.8)] 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - A High-Efficiency 35GHz Rectenna with compact structure for rectenna arrays
摘要： A 35GHz rectenna with high efficiency and compact structure is proposed in this paper. A patch antenna fed by the coupling slot is employed to receive power from free space. The structure of designed rectifier is compact and printed on the bottom side of the antenna. The input low-pass or band-pass filter of the rectifier is removed. Instead, a short ended microstrip line is introduced as a band stop structure to block the harmonics and match the impendence. This circuit configuration highly simplifies the total topology and is suitable for rectenna arrays applications. Furthermore, removing the input filters reduced the insertion loss and thus improved the microwave-to-dc (MW-DC) conversion efficiency. The rectenna is designed, fabricated and measured, a maximum MW-DC efficiency of 53.2% is achieved for a power density of 51.2 mW/cm2 with the dc load 250 Ω at 35 GHz.
关键词： compact structure,millimeter-wave rectenna,high conversion efficiency,WPT
更新于2025-09-23 15:22:29
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A Dual-Mode RF Power Harvesting System With an On-Chip Coil in 180-nm SOI CMOS for Millimeter-Sized Biomedical Implants
摘要： In this paper, we present a dual-mode power harvesting system for millimeter-sized biomedical implants that are immune to the variation of wireless link parameters and loading. The design includes a multistage full-wave voltage rectifier, a power management unit, and a low dropout voltage regulator. Depending on the received RF power level and the required power by the load, power delivery is conducted in a continuous or duty-cycled mode. The system is fabricated in 180-nm silicon on insulator (SOI) CMOS technology with an active area of 2.56 mm2 including an on-chip coil. RF power is transferred to the chip from a 2 × 2 cm2 coil through 10 mm of air at 434 MHz. The efficiency of the designed wireless link, which is the power transfer efficiency from the external coil to the on-chip coil, reaches up to 0.68% (?21.7 dB) at 10-mm separation through air. Keeping the transmitted RF power below 24 dBm, the system can provide a 1.08-V dc voltage for resistive loads larger than 20 kΩ continuously over time. When the harvested power is not enough to drive the load continuously, the system operates in the duty-cycled mode. Measurement results show that the system can drive a 1-kΩ load in the duty-cycled mode when the transmitted power level is 15 dBm.
关键词： voltage rectifier,millimeter-sized implant,power management,on-chip coil,CMOS,rectenna,low dropout (LDO) regulator,wireless power transfer (WPT)
更新于2025-09-23 15:21:21
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[IEEE 2018 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting - Boston, MA, USA (2018.7.8-2018.7.13)] 2018 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting - A Circularly Polarized Triple-Feed Multi-Beam Array Antenna Using Planar Magic- Ts
摘要： A circularly polarized triple-feed multi-beam array antenna employing two types of planar magic-Ts is proposed. The proposed array antenna, where each of the antenna elements are circularly polarized antennas provides three different radiation patterns in the x-z and y-z planes. The performance of the proposed antenna is experimentally evaluated. The 10-dB impedance bandwidth of the antenna is better than 3.1% and 3-dB axial ratio bandwidth is 0.81%. All these features make the proposed antenna very suitable for direction-of-arrival estimation antennas, beam steering antennas and wide-angle rectennas.
关键词： magic-T,wide-angle rectenna,direction-of-arrival estimation antenna,triple-feed,beam steering antenna
更新于2025-09-19 17:15:36
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High-current density and high-asymmetry MIIM diode based on oxygen-non-stoichiometry controlled homointerface structure for optical rectenna
摘要： optical rectennas are expected to be applied as power sources for energy harvesting because they can convert a wide range of electromagnetic waves, from visible light to infrared. the critical element in these systems is a diode, which can respond to the changes in electrical polarity in the optical frequency. By considering trade-off relationship between current density and asymmetry of IV characteristic, we reveal the efficiency limitations of MIM diodes for the optical rectenna and suggest a novel tunnel diode using a double insulator with an oxygen-non-stoichiometry controlled homointerface structure (Mox/ Mox?y). A double-insulator diode composed of pt/tio2/tio1.4/ti, in which a natural oxide layer of tio1.4 is formed by annealing under atmosphere. The diode has as high-current-density of 4.6 × 106 A/m2, which is 400 times higher than the theoretical one obtained using Pt/TiO2/ti MiM diodes. in addition, a high-asymmetry of 7.3 is realized simultaneously. These are expected to increase the optical rectenna efficiency by more than 1,000 times, compared to the state-of-the art system. Further, by optimizing the thickness of the double insulator layer, it is demonstrated that this diode can attain a current density of 108 A/m2 and asymmetry of 9.0, which are expected to increase the optical rectenna efficiency by 10,000.
关键词： optical rectenna,oxygen-non-stoichiometry controlled homointerface structure,high-asymmetry,high-current density,MIIM diode
更新于2025-09-19 17:13:59
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A 2.4 GHz Rectenna based on a Solar Cell Antenna Array
摘要： Combined solar and radiofrequency harvesting systems are drawing attention by offering self-powered ability to low power devices, an essential aspect to the success of the Internet of Things. One of the main challenges of these harvesting systems is to improve rectennas ef?ciency by optimizing the individual energy collection and conversion capacity of each source. To overcome this issue, this letter presents a novel 2.4 GHz rectenna structure for solar and radiofrequency energy harvesting applications based on a coplanar antenna array integrated with multi-crystalline solar cells, whose aluminum rear terminals are used as radiators for the antenna array. The results obtained by simulations and measurements showed that it is possible to collect energy from two different types of sources in a complementary manner, using the rectenna design proposed, making possible to feed low-power devices remotely.
关键词： energy harvesting,Solar cell rectenna,coplanar patch antenna,low power recti?er
更新于2025-09-12 10:27:22
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[Lecture Notes in Electrical Engineering] Engineering Vibration, Communication and Information Processing Volume 478 (ICoEVCI 2018, India) || Design of an Energy Harvesting System for Wireless Power Transmission Using Microstrip Antenna
摘要： Power supply drives technological devices. As the wired world looks long antiquated, it is imperative transition towards wireless power transmission (WPT). WPT has been lately enticing in a varying range of applications in numerous ?elds and has also become a very alluring area of research activity because of the potential it has in providing solutions to our daily requirement, so the need arises to delve into it to explore new, innovative and ef?cient means of energy transmission. WPT will be indispensable in the imminent future, as this technology assists in the transmission of electrical energy to any device from the power source using air as the transmission medium without the use of any conductors. In this paper, an energy harvesting device is proposed to convert ambient electromagnetic waves, predominantly from the 2.4 GHz ISM radio frequency (RF) channel into direct current (DC) electricity. A microstrip antenna is designed along with a booster circuit to help charge devices wirelessly. This novel technology could be used for charging phone batteries on-the-go, thereby eliminating the hassles of wired connections.
关键词： Rectenna,Wireless power transmission,Energy harvesting,Wireless charging,Microstrip patch antenna
更新于2025-09-10 09:29:36
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A compact omnidirectional dual-circinal rectenna for 2.45?GHz wireless power transfer
摘要： A compact dual-circinal rectenna with omnidirectional characteristic is designed for microwave wireless power transmission at 2.45 GHz. A novel dual-circinal receiving antenna with the reflection coefficient of ?32.5 dB is proposed which is formed by expanding folded curves. By designing an impedance matching network with a 60 (cid:1) radial stub and a single stub, a rectifier is presented with the maximum efficiency of 55.6 % and the output dc voltage of 1.19 V under the input power of 0 dBm. Simulation and measurements have been carried out for the antenna and the rectifier. The measured results agree well with the simulated value. The results of rectenna experiment show that the maximum conversion efficiency is 51% at 2.45 GHz when the input power is 0 dBm. The proposed rectenna has the characteristics of compact size and omnidirectional harvesting which are advantageous in RF energy harvesting applications.
关键词： 2.45 GHz,wireless power transfer,dual-circinal rectenna,omnidirectional,compact
更新于2025-09-10 09:29:36