Showing papers on "Voltage multiplier published in 2019"

A New High Step-Up Multi-Input Multi-Output DC–DC Converter

Abstract: In this paper, a new multi-input multi-output (MIMO) dc–dc converter with high step-up capability is proposed for wide power ranges. Also, in order to increase each output voltage, diode–capacitor voltage multiplier (VM) stages are utilized in the proposed converter. The number of input stages, output stages, and VM stages are arbitrary and dependent on design conditions. At first, the general structure of proposed MIMO converter is presented. Then, in order to explain the converter operation, we walk through the design of a 1-kW four-input two-output example, including loss and efficiency calculations. We validate the design with a prototype that matches efficiency calculations.

High Gain Transformer-Less Double-Duty-Triple-Mode DC/DC Converter for DC Microgrid

Abstract: High-gain DC/DC converters with high efficiency are needed in dc microgrid owed to the low voltage of power sources, e.g., photovoltaic-cell and fuel-cell. This paper proposed a new high-gain double-duty-triple-mode (DDTM) converter for dc-microgrid applications. The proposed DDTM converter operates in three modes to achieve higher voltage gain without utilizing transformer, coupled inductor, voltage multiplier, and multiple voltage lifting techniques, e.g., triple, quadruple voltage lift. The modes of operation of the converter are controlled through three switches with two distinct duty ratios (double duty) to achieve wide range duty ratio. The operating principle, voltage gain analysis, and efficiency analysis of the proposed converter are discussed in detail and to show its benefits comparison is provided with the existing high-gain converters. The boundary operating condition for continuous conduction mode (CCM) and discontinuous conduction mode (DCM) is presented. The prototype of the proposed converters with 500-W power is implemented in the laboratory and experimentally investigated, which validate the performance and feasibility of the proposed converter. Due to double duty control, the proposed converter can be controlled in different ways and the thorough discussion on controlling of the converter is provided as a future scope.

An Interleaved High Step-Up Converter With Coupled Inductor and Built-In Transformer Voltage Multiplier Cell Techniques

Abstract: This paper presents an interleaved converter that benefits the coupled inductor and built-in transformer voltage multiplier cell (VMC). Compared with the other converters with only a built-in transformer or only a coupled inductor, the combination of these techniques gives an extra degree of freedom to increase the voltage gain. The VMC is composed of the windings of the built-in transformer and coupled inductors, capacitors, and diodes. The voltage stress of MOSFETs is clamped at low values and can be controlled via the turns ratio of the built-in transformer and coupled inductor that increases the design flexibility. Moreover, the energy of the leakage inductances, is recycled to the clamp capacitors which avoids high voltage spikes across MOSFETs. In addition, the current falling rate of the diodes is controlled by the leakage inductances, and the reverse current recovery problem is alleviated. Meanwhile, due to the interleaved structure of the proposed converter, the input current ripple is minimized and the current stress of the power devices is decreased. All of these factors improve the efficiency of the proposed converter in high-current and high-voltage applications. The principle operation and steady-state analysis is given to explore the advantages of the proposed converter. Finally, a 1.3-kW prototype with 50–600 V voltage conversion is built to demonstrate the effectiveness of the proposed converter.

Single-Switch High Step-Up DC–DC Converter With Low and Steady Switch Voltage Stress

Abstract: In this paper, a new high voltage gain step-up dc–dc converter is proposed for interfacing renewable power generation. The configuration optimally integrates both the coupled-inductor and switched-capacitor techniques to achieve an ultra-high step-up gain of voltage conversion with low voltage stress and high efficiency. It consists of a voltage boost unit, a passive clamp circuit, and a symmetrical voltage multiplier network. The structure becomes modular and extendable without adding any extra winding for ultra-high step-up voltage gain. The proposed topology not only reduces the voltage stress on the main switch but also maintains it steady for the entire duty cycle range. Furthermore, the reverse recovery issue of the diodes is alleviated through the leakage inductance of the coupled inductor. The operation principle and steady-state analysis are presented in detail. Experimental evaluation validates the claimed advantages and demonstrates a well-distributed efficiency curve and the peak of 96.70%.

High-Voltage-Gain DC–DC Step-Up Converter With Bifold Dickson Voltage Multiplier Cells

Abstract: This paper presents an interleaved boost converter with a bifold Dickson voltage multiplier suitable for interfacing low-voltage renewable energy sources to high-voltage distribution buses and other applications that require a high-voltage-gain conversion ratio. The proposed converter was constructed from two stages: an interleaved boost stage, which contains two inductors operated by two low-side active switches, and a voltage multiplier cell (VMC) stage, which mainly consists of diodes and capacitors to increase the overall voltage gain. The proposed converter offers a high-voltage-gain ratio with low voltage stress on the semiconductor switches as well as the passive components. This allows the selection of efficient and compact components. Moreover, the required inductance that ensures operation in the continuous conduction mode (CCM) is lower than the one in the conventional interleaved boost converter. The distinction of the proposed converter is that the inductors’ currents are equal, regardless of the number of VMCs. Equal sharing of interleaved boost-stage currents reduces the conduction loss in the active switches as well as the inductors and thus improves the overall efficiency, as the conduction power loss is a quadratic function. In this paper, the theory of operation and steady-state analysis of the proposed converter are illustrated and verified by simulation results. A $\text{200-W}$ hardware prototype was implemented to convert a $\text{20-V}$ input source to a $\text{400-V}$ dc load and validate both the theory and the simulation.

High step-up DC–DC converter with coupled inductor suitable for renewable applications

Abstract: In this study, a new non-isolated high step-up DC-DC converter is presented with high-voltage gain which is suitable for renewable applications. The proposed converter uses coupled inductor and voltage multiplier cell (diode capacitor) for increasing the voltage level. The voltage gain of the proposed converter can be increased by selecting the appropriate turns ratio of coupled inductor. Voltage multiplier cell consists of two diodes and two capacitors which are used to obtain high-voltage gain. The diode-capacitor cell is used as a clamp circuit, which leads to reducing the voltage stress across the semiconductors. The proposed converter has a single power switch which causes the control of the proposed converter is simple. Also, the power switch is used with lower ON-state resistant ( R DS-ON ). The zero-current switching of the diode is obtained in OFF state. Therefore, the conduction losses are decreased with lower normalised voltage stress across semiconductors. To prove the performance of the proposed converter, theoretical analysis and comparison with other converters are provided. To confirm the benefits of the proposed converter, a laboratory prototype with 20 V input voltage, 200 V output voltage and about 200 W power level at operating 25 kHz is built and tested.

A Family of Scalable Non-Isolated Interleaved DC-DC Boost Converters with Voltage Multiplier Cells

Abstract: In this paper, a family of non-isolated interleaved high-voltage-gain DC-DC converters is presented. This family can be used in a wide variety of applications, such as in a photovoltaic systems interface to a high voltage DC distribution bus in a microgrid and an X-ray system power supply. The general structure of this family is illustrated and consists of two stages: an interleaved boost stage and a voltage multiplier stage. The interleaved boost stage is a two-phase boost converter, and it converts the input DC voltage to an AC square waveform. Moreover, using the interleaved boost stage increases the frequency of the AC components so that it can be easily filtered with smaller capacitors and, therefore, makes the input current smoother than the one from the conventional boost converter. The voltage multiplier cell (VMC) can be a Dickson cell, Cockcroft-Walton (CW), or a combination of the two. The VMC stage rectifies the square-shaped voltage waveform coming from the interleaved boost stage and converts it to a high DC voltage. Several combinations of VMCs and how they can be extended are illustrated, and the difference between them is summarized so that designers can be able to select the appropriate topology for their applications. An example of this converter family is illustrated with detailed modes of operation, a steady-state analysis, and an efficiency analysis. The example converter was simulated to convert 20 V DC to 400 DC , and a 200 W hardware prototype was implemented to verify the analysis and simulation. The results show that the example has a peak efficiency of 97% of this family of converters and can be very suitable for interfacing renewable energy sources to a 400 V DC DC distribution system.

A novel method for autonomous remote condition monitoring of rotating machines using piezoelectric energy harvesting approach

Abstract: This paper presents a novel autonomous method for condition monitoring of rotating machines during operation based on radio frequency (RF) pulse transmission using energy harvesting from operational vibration. An energy harvesting unit is designed to generate and rectify the energy harvested from the machine vibration using Voltage Multiplier (VM) circuit and to store the energy into a capacitor. Then, this energy harvesting unit runs a smart system consisting of a microcontroller and the RF transmitter designed to send a pulse at specific capacitor voltage. A pulse-based condition monitoring approach is introduced which monitors the state of the machine during the operation. In order to estimate power output of the piezoelectric harvester for a realistic vibration signal, the Fourier Transform concept for signal decomposition is incorporated into the well-known electromechanical distributed parameter model. Using experimental data, performance of this autonomous condition monitoring system is tested for a water pump at different conditions. To do so, acceleration data from a centrifugal water pump are acquired with an accelerometer, which then decomposed into a series of harmonics using Fast Fourier Transform. Then using analytical distribute model, a bimorph energy harvester with two Piezoceramic layers is optimized to generate maximum power from the water pump vibration. Consequently, the condition monitoring of the water pump is performed using the presented pulse-based approach. Results of this study show that, the fault diagnosis can be performed autonomously by applying the pulse-based method presented in this work, and by using the piezoelectric harvesting device as an energy source.

A Switched-Capacitor DC–DC Converter With Variable Number of Voltage Gains and Fault-Tolerant Operation

Abstract: This paper presents research results of voltage gain number control methods of a power electronic resonant zero-current switching dc–dc switched-capacitor (SC) voltage multiplier (SCVM) in a topology with fault tolerance capability (FSCVM) The converters operated under the basic switching patterns are constant-voltage-gain dc–dc series-parallel resonant SC converters However, this paper presents a method for the output voltage regulation by a special switching strategy A variable voltage gain is made possible by selecting the number of active switching cells, using an appropriate control method This creates a set of voltage ratio ranges In addition, the proposed topology and method of control enable a fault-tolerant operation of the FSCVM under various failures of the device The paper presents an analysis of the concept, simulation results and an experimental verification in a three-cell FSCVM dc–dc resonant boost converter operating at a 200-watt charge Issues regarding the selection of components related to the problem of inrush currents that can occur during the voltage ratio increase are also analyzed in this paper, and the design for low inrush currents is demonstrated

Integrated Cold Start of a Boost Converter at 57 mV Using Cross-Coupled Complementary Charge Pumps and Ultra-Low-Voltage Ring Oscillator

Abstract: This paper demonstrates an on-chip electrical cold-start technique to achieve low-voltage and fast start-up of a boost converter for autonomous thermal energy harvesting from human body heat. An improved charge transfer through high gate-boosted switches by means of cross-coupled complementary charge pumps enables voltage multiplication of the low input voltage during cold start. The start-up voltage multiplier operates with an on-chip clock generated by an ultra-low-voltage ring oscillator. The proposed cold-start scheme implemented in a general-purpose 0.18- $\mu \text{m}$ CMOS process assists an inductive boost converter to start operation with a minimum input voltage of 57 mV in 135 ms while consuming only 90 nJ of energy from the harvesting source, without using additional sources of energy or additional off-chip components.

Interleaved-Input Series-Output Ultra-High Voltage Gain DC–DC Converter

Abstract: The ultra-high voltage gain dc–dc converters are extremely required because of the low voltage level of many nonpolluting power resources. This paper proposes an ultra-high voltage gain converter based on an interleave technique and using three-winding coupled inductor and voltage multiplier cell. The interleave technique is useful for reducing the size of the filter components. In the proposed converter, high voltage gain is achieved without extreme duty cycle of solid-state switches. The voltage stress across the semiconductor devices can be reduced by increasing the turn ratio of the secondary of the coupled inductors. In addition, because of the implementation of the interleave structure, peak-to-peak variation of the main input current and switching losses are substantially reduced. The steady-state principles of the proposed converter in continuous conduction mode operation are given. Also, design equations are presented. Validity and performance of the proposed converter are surveyed by simulation and experimental results of a 120 W prototype.

A Novel Multiphase High Step-Up DC/DC Boost Converter With Lower Losses on Semiconductors

Abstract: In this paper, a new multiphase interleaved dc/dc converter is presented. The proposed converter consists of two symmetric sections. Each section consists of several switches, inductors, diodes, and capacitors. In order to obtain high voltage gain, the proposed converter can be extended to n stages of voltage multiplier units which are used between the phases. Hence, the voltage gain of the proposed transformerless converter will be significantly high. In addition, the other advantage of the proposed converter not only contains lower voltage stress on the semiconductors but also leads to high efficiency for different values of duty cycles. The value of input current ripple is low due to using the interleaved technique. To illustrate the merits of the presented converter, comparison results with other converters are provided. The principle of operation in three-phase case, both theoretical analysis and experimental results of two prototype in different ranges with operating at 25 kHz are provided.

Modularized Equalization Architecture With Voltage Multiplier-Based Cell Equalizer and Switchless Switched Capacitor Converter-Based Module Equalizer for Series-Connected Electric Double-Layer Capacitors

Abstract: This paper proposes a novel modular equalization architecture for series-connected electric double-layer capacitor (EDLC) modules, each consisting of multiple cells connected in series. Cell voltages in a module are equalized by an inductive voltage divider (IVD)-voltage multiplier (VM)-based cell equalizer, while module voltages are unified by switched capacitor converters (SCCs). Square wave voltages generated at switching nodes of the IVD-VM-based cell equalizers are utilized to drive the SCC-based module equalizers, realizing the switchless topology of SCC-based module equalizers. The required switch count of the proposed system can be halved compared to conventional systems, allowing simplified circuit. An experimental equalization test for three EDLC modules, each consisting of six cells in series, was performed from an initially voltage-imbalanced condition. Module and cell voltages were equalized at different rates, and the equalization performance of the proposed modular equalization system was successfully demonstrated.

Ultra-step-up dc–dc converter with low-voltage stress on devices

Abstract: This study suggests a novel ultra-step-up dc-dc converter with low normalised voltage stress across the power devices. The proposed converter incorporates the conventional boost converter with a self-lift circuit and charge pump concept and utilises a voltage multiplier cell at the output side. In the input side, two inductors are magnetised during the switch on-time. During the switch off-time, the stored energy in these inductors, charge pump capacitor and input source, is delivered to the load. Accordingly, the proposed converter is capable of providing high voltage gains with a small duty cycle. Besides, the voltage stress across the power devices is low. Therefore, the MOSFET switch with low R DS-on and devices with reduced nominal voltage can be used which in turn reduces the conduction and turn-on losses. The analysis of the voltage and current stresses is accomplished. The circuit performance is compared with other solutions in the literature in terms of voltage gain and normalised voltage stress of the semiconductors. Eventually, to validate the theoretical analysis, the experimental results are given.

Module-Integrated Converter Based on Cascaded Quasi-Z-Source Inverter With Differential Power Processing Capability for Photovoltaic Panels Under Partial Shading

Abstract: Conventional microinverter or module-integrated converter (MIC)-based photovoltaic (PV) systems are prone to be complex and costly because each MIC requires not only a boost converter to bridge a huge voltage gap between a PV panel and grid but also desirably a differential power processing (DPP) converter to preclude partial shading issues. This paper proposes a novel MIC based on cascaded quasi-Z-source inverters (qZSIs) with DPP capability. A traditional qZSI and voltage multiplier (VM)-based DPP converter are integrated into a single unit with sharing active switches and magnetic components, achieving system- and circuit-level simplifications. In addition, a novel control strategy utilizing two control freedoms of shoot-through duty cycle $d_{st}$ and modulation index M to simultaneously perform maximum power point tracking (MPPT) and DPP function, respectively, is also presented. A 150 W prototype for a standard PV panel consisting of three substrings is built, and experimental tests are performed emulating partial shading conditions. The results demonstrate that the proposed integrated qZSI could perform MPPT with satisfactory preventing partial shading issues while generating ac voltage at the inverter output.

Nonisolated Symmetrical Interleaved Multilevel Boost Converter With Reduction in Voltage Rating of Capacitors for High-Voltage Microgrid Applications

Abstract: This article proposed a nonisolated symmetrical interleaved multilevel boost converter for high-voltage microgrid applications. The proposed converter configuration is derived from the integration of a voltage multiplier (VM) circuit with the front-end structure of the classical two-phase interleaved converter. Moreover, equal voltage rating capacitors and diodes are suitable to design multiple stages of the proposed converter. The proposed converter can feed from two independent sources or single source in the interleaved approach. The continuous input current, high-voltage gain, reduced voltage rating of capacitor (that causes reduction in cost), reduced components, and flexibility in number of sources make the proposed converter more attractive for renewable dc-microgrid applications such as, photovoltaic (PV) system, fuel cell (FC) system, and hybrid PV-FC system. Furthermore, the voltage gain of the converter can be increased by just adding similar stages of VM without preferring the high-voltage rating capacitors and without disturbing the front-end structure of the converter. Nonidealities are considered to analyze the proposed converter in a more practical way. The characteristics and operation of the proposed converter are discussed in this article with the continuous conduction mode and Discontinuous Conduction Mode boundary conditions. The design of the reactive components and selection of semiconductor devices are discussed. Additionally, the proposed converter is compared with recently proposed dc–dc multilevel converters. To support the proposed work, simulation and experimental results are provided which shows a good agreement with the analytical approach.

Ultra-high step-up two-input DC–DC converter with lower switching losses

Abstract: In this study, a novel isolated ultra-high step-up two-input DC–DC converter with low-voltage stress across semiconductors is presented. In the proposed converter, outputs are isolated from the inputs by a high-frequency transformer and the leakage inductance of the transformer is used to soft switching (zero-current switching) of the power switches when they are turned-on and alleviate the reverse recovery problems of the diodes. This converter can be operated as an interleaved single-input converter with a 180° phase shift. The converter benefits from the advantages of both the conventional boost converter and diode-capacitor voltage multiplier (VM) stages. The primary side of the transformer consists of two-input cells based on the conventional boost converter and the secondary side consists of diode-capacitor VM stages which are used to increase the voltage gain and decrease the nominal voltage stress across semiconductors. To confirm the converter performance, the mathematical analysis and simulation result are presented, in addition, the comparison between the proposed converter and other converters which are presented in recent studies is presented. An experimental prototype 410 V/280 W of the converter with 40 and 45 V input voltages is provided to illustrate the correct operation of the presented converter.

High Step-Up Nonisolated ZVS/ZCS DC–DC Converter for Photovoltaic Thin-Film Module Applications

Abstract: Photovoltaic (PV) thin-film modules normally present higher voltages at the maximum power points than crystalline silicon ones. This feature makes the usage of low-voltage MOSFETs (≤100 V) unfeasible in high step-up boost-based converters. In order to solve this drawback, this paper proposes a novel high step-up nonisolated dc–dc converter based on the classical synchronous buck converter with coupled inductor and voltage multiplier techniques. Besides reducing the voltage stress on the active switches, the proposed converter also requires a coupled inductor with lower core-window product, allowing the use of a smaller magnetic device. The resonant operation mode of the proposed converter enables zero-voltage-switching turn-on of active switches and zero-current-switching turn-off of diodes, which increases its efficiency. A 150-W prototype, able to work with a large variety of commercial PV thin-film modules, with 55–85-V input and 400-V output voltages, is built to verify the developed analysis. Experimental results show that the maximum obtained efficiency is nearly 98%, and the weighted California Energy Commission efficiencies are greater than 96.7% over the whole input voltage range.

Design of a High Step-up DC-DC Power Converter with Voltage Multiplier Cells and Reduced Losses on Semiconductors for Photovoltaic Systems

Abstract: A high step-up dc-dc converter based on an isolated dc-dc converter with voltage multiplier cells for photovoltaic systems is essentially introduced in this paper. The proposed converter can provide a high step-up voltage gain. The switch voltage stress and losses on semiconductors are significantly reduced through this work Furthermore, the proposed converter can reliably offer and provide continuous input current which can be basically used for integrating photovoltaic systems to convert 30 V to 480 V dc bus. The ripple on the input current is minimized due to the isolated converter, and the proposed converter is fed by a single input voltage. The operation modes and the characteristics of the aforementioned converter are thoroughly analyzed. The components selection, simulation results and experiment results are mainly verified by using MATALB Simulink. Consequently, a 360W hardware prototype is implemented to validate the design and the theory.

An ultra-low power, low voltage DC-DC converter circuit for energy harvesting applications

Abstract: In this paper a compact, fully-integrated voltage multiplier with a low start-up voltage is presented for energy harvesting applications. Two voltage doublers are cascaded with the overall conversion ratio of 2 and 4. The voltage multiplier has a 2-phase clock signal with a wide range of operating frequency from 1 kHz to 1 MHz. Cascading and positive feedback with cross-coupled gates have been used to increase the efficiency and conversion ratio of the converter. The DC-DC converter has an efficiency of more than 70% when operating from a 0.34 V input voltage and generating 1.28 V output voltage. The proposed voltage multiplier has a power consumption of 36 nW to 1.24 μW for input voltage range of 280–450 mV in 0.18 μm CMOS technology.

Soft-Switching High Step-Up/Down Bidirectional DC–DC Converter

Abstract: A nonisolated bidirectional dc–dc converter with high voltage gain, low voltage stress, low component count, and soft-switching features is presented in this paper. In this topology, coupled inductors and voltage multiplier cells are merged to achieve high step-up/down voltage gain. Also, due to using active clamp circuits, the voltage stress of power switches is relatively low. Thus, the low voltage switches with low on-resistance can be employed to reduce the conduction losses. Furthermore, zero-voltage switching is accomplished in both high step-up and high step-down modes for all power switches, and due to zero-current switching operation of all antiparallel diodes, the reverse recovery losses are reduced. In order to verify the theoretical analysis and the converter performance, a 200 W prototype circuit of the proposed converter is implemented in the laboratory.

Diode Reverse Recovery Process and Reduction of a Half-Wave Series Cockcroft–Walton Voltage Multiplier for High-Frequency High-Voltage Generator Applications

Abstract: This paper investigates the diode reverse recovery process and reduction of a half-wave (HW) series Cockcroft–Walton (CW) voltage multiplier based on the steady-state analysis for high-frequency high-voltage (HV) generator applications. The diode reverse recovery process for a multistage voltage multiplier is analyzed after the introduction of steady-state operation. The diode reverse recovery problem is the bottleneck to further increase the circuit operation switching frequency for achieving high power density and short HV pulse rise and decay times. The diode reverse recovery problem is mainly caused by the diodes in the first-stage voltage multiplier. It is suggested that the most effective and economic way to alleviate the diode reverse recovery problem is by employing diodes without reverse recovery such as silicon carbide Schottky diodes in the first stage only. The silicon carbide Schottky diode without reverse recovery needs to be used only in the first stage of the voltage multiplier to effectively mitigate the reverse recovery problems at high frequency. The 300 kHz switching frequency three-stage voltage multiplier circuit hardware prototype experimental results finally validate the analysis. A technology demonstrator of a 300 kHz 8 kW 160 kV HV generator based on the proposed hybrid silicon carbide and silicon diode solution for the HW series CW voltage multiplier is provided finally.

A Coupled-Inductor-Based LCC Resonant Converter With the Primary-Parallel–Secondary-Series Configuration to Achieve Output-Voltage Sharing for HV Generator Applications

Abstract: In this paper, a coupled-inductor-based LCC resonant converter with the primary-parallel–secondary-series (PPSS) configuration is proposed to achieve output-voltage sharing ability for HV generator applications. The PPSS configuration of the LCC resonant converter with the voltage multipliers is introduced to achieve high output-voltage and increase the output-power level. However, the variations of the magnetizing inductance, leakage inductance, and winding capacitance of the HV transformer and voltage multiplier impact on the output-voltage sharing performance. Subsequently, the resonant inductors in the primary side of the conventional LCC resonant converters with the PPSS configuration are coupled to achieve the output-voltage sharing without any additional circuits and control efforts. Furthermore, an analytical equivalent circuit model considering the magnetizing inductor of the HV transformer is derived to analyze the output-voltage sharing ability. Moreover, the design method for the coupled inductors considering the output-voltage sharing performance affected by the leakage inductance of the coupled inductors is presented. Finally, the output-voltage sharing performance of the proposed coupled-inductor-based LCC resonant converter with the PPSS configuration is validated by the experimental results of a 50-V input, 5-kV output 100-W prototype. The prototype experimental results show that the unbalance voltage degree decreases from 67.7% to 8.5% with the utilization of the coupled inductor.

High-Efficiency Millimeter-Wave CMOS Switching Rectifiers: Theory and Implementation

Abstract: This article proposes the concept of millimeter-wave (mm-wave) switching rectifiers originated from drain-pumped mixers. The topology and circuit design methodology are distinctly different from other CMOS mm-wave rectifiers which adopt voltage multiplier techniques. Operation principle and RF-to-dc power conversion efficiency (PCE) of the proposed switching rectifiers are analyzed to overcome the fundamental limits on achievable performance of switching rectifiers at mm wave. In order to demonstrate the utility of the proposed concept, two prototypes in 65-nm bulk CMOS technology have been implemented: two fully integrated switching rectifiers operating at Ka-band and W-band. A peak PCE of 36.5% at 35 GHz with a load resistance of $50~\Omega $ at about 15-dBm input power is measured for the Ka-band rectifier. Measurement results for the W-band rectifier also indicate that the PCE peaks at 27% at 91 GHz for a load resistance of $43~\Omega $ at about 16-dBm input power. To the best of our knowledge, the two fully integrated rectifiers which occupy the smallest chip area exhibit a competitive PCE reported among Ka-band and W-band CMOS rectifiers, competing well with GaAs counterparts where the Schottky diode is available.

Single-switch high step-up boost converter based on a novel voltage multiplier

Abstract: A single-switch high step-up boost converter based on a novel voltage multiplier (VM) has been proposed in this study. Compared to traditional boost converter, not only the voltage conversion ratio has been increased, but also voltage stress across semiconductor devices has been decreased. Moreover, the voltage conversion ratio and voltage stress of switch of the proposed converter can be adjusted by the number of the VM cells. The control and drive circuits for the proposed converter is as simple as boost converter as there are no additional switches. Working principles and performance characteristics of the proposed converter have been analysed in detail. A 200 W experimental prototype with three VMs has been built to validate the theoretical analysis.

Interleaved High Step-Up Converter With Coupled Inductor and Voltage Multiplier for Renewable Energy System

Abstract: The concepts of dual coupled inductors and voltage multiplier cell are integrated to derive a novel non-isolated interleaved high step-up boost converter in this paper. At the input, due to the interleaved dual coupled inductors and voltage multiplier cell, the converter inhibits current ripple and reduced voltage stress for the power devices; At the output, the secondary sides of the two coupled inductors are connected in series to achieve the purpose of much higher voltage gain and lower voltage stress on the power devices. Therefore, lower voltage rating MOSFETs and diodes can be selected to reduce both switching and conduction losses. In addition, the leakage inductance energy of two coupled inductors can be absorbed and recycled to the output, and the reverse-recovery problem of diodes can be effectively suppressed. Zero current switching (ZCS) turn-on is realized for the power switches to reduce the switching loss. The working principle and steady-state characteristics of the converter are analyzed in detail. The voltage balance of the output capacitors and input current sharing by two interleaved phases are realized through the double closed-loop control of voltage and current. Finally, a 400 W laboratory prototype with 25~30 V input and 400 V output is built to verify the significant improvements of the proposed converter.

Analysis of Dickson Voltage Multiplier for RF Energy Harvesting

Abstract: This paper presents the RF energy harvesting parameters depending on the efficiency and the output DC voltage for input powers between −35dBm to 25dBm. In this study, multi-stage Dickson voltage multiplier (DVM) from 2 to 6-stages are designed and implemented with various load resistance i.e. 20–50–100–500 kΩ and different matching topology such L-matching, T-matching, and Pi-matching are applied, and also two Schottky diode models (e.g. HSMS-2852 and HSMS-2822) are used to design the DVM to see their effect on the efficiency. All the simulations are done by using the Advance Design System (ADS) 2017. The target frequency selected in the design is 915 MHz for Industrial, Scientific and Medical Radio Band (ISM band). The simulation results show that high efficiency and high output DC voltage are obtained for the DVM circuit design with matching compared to the DVM circuit without matching for low input power.

Integrated Building Cells for a Simple Modular Design of Electronic Circuits with Reduced External Complexity: Performance, Active Element Assembly, and an Application Example

Abstract: This paper introduces new integrated analog cells fabricated in a C035 I3T25 0.35-μm ON Semiconductor process suitable for a modular design of advanced active elements with multiple terminals and controllable features. We developed and realized five analog cells on a single integrated circuit (IC), namely a voltage differencing differential buffer, a voltage multiplier with current output in full complementary metal–oxide–semiconductor (CMOS) form, a voltage multiplier with current output with a bipolar core, a current-controlled current conveyor of the second generation with four current outputs, and a single-input and single-output adjustable current amplifier. These cells (sub-blocks of the manufactured IC device), designed to operate in a bandwidth of up to tens of MHz, can be used as a construction set for building a variety of advanced active elements, offering up to four independently adjustable internal parameters. The performances of all individual cells were verified by extensive laboratory measurements, and the obtained results were compared to simulations in the Cadence IC6 tool. The definition and assembly of a newly specified advanced active element, namely a current-controlled voltage differencing current conveyor transconductance amplifier (CC-VDCCTA), is shown as an example of modular interconnection of the selected cells. This device was implemented in a newly synthesized topology of an electronically linearly tunable quadrature oscillator. Features of this active element were verified by simulations and experimental measurements.