scholarly journals MAXIMUM POWER OF THE HF ANTENNA TUNER SWITCHED BY PIN DIODES AT LOAD MISMATCH

T-Comm ◽  
2020 ◽  
Vol 14 (10) ◽  
pp. 26-32
Author(s):  
Oleg V. Varlamov ◽  
Keyword(s):  
High Speed ◽  
Load Resistance ◽  
Phase Shifters ◽  
Maximum Power ◽  
Matched Load ◽  
Pin Diodes ◽  
Mobile Objects ◽  
Switching Power ◽  
Literary Sources ◽  
Control Circuits

PIN diodes, as inertial nonlinear elements, are widely used in transceiver equipment of various frequency ranges as limiters, attenuators and phase shifters. Also, with their help, it is possible to implement double-sided switching elements used, among other things, in switches and automatic antenna-matching devices of the HF range. Literary sources note that PIN diode switches in the HF range are capable of switching power up to 2 kW. In this case, only the task of switching the sub-octave bandpass filters of the transmitter is meant when operating at a perfectly matched load in a 50 Ohm path. The article discusses the features of the operation of PIN diodes in the HF range and determines the limiting values of the switched power depending on the parameters of the device and the load resistance. Examples of the circuit design of high-speed control circuits are given. The analysis of the maximum power of an automatic antenna-matching device of the HF range, carried out using the example of the most famous samples, with a load mismatch with PIN diodes, showed that in the case of a matched load, they can be used up to power levels practically equal to 2 kW. With a strong load mismatch, which is observed in most practical cases, especially when using communication facilities on mobile objects with electrically short antennas, the maximum power levels are reduced to 170 W when operating at frequencies above 3 MHz and to 100 W when operating at frequencies above 1 MHz.

scholarly journals Influence of Parasitic Resistances on the Input Resistance of Buck and Boost Converters in Maximum Power Point Tracking (MPPT) Systems

Electronics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1464
Author(s):  
Marcin Walczak ◽  
Leszek Bychto
Keyword(s):  
Input Resistance ◽  
Load Resistance ◽  
Maximum Power ◽  
Solar Panels ◽  
Maximum Power Point ◽  
Boost Converters ◽  
Pv Systems ◽  
Point Tracking ◽  
Pv Panel ◽  
Power Point

DC/DC converters are widely used in photovoltaic (PV) systems to maximize the power drained from solar panels. As the power generated by a PV panel depends on the temperature and irradiance level, a converter needs to constantly modify its input resistance to remain at the maximum power point (MPP). The input resistance of a converter can be described by a simple equation that includes the converter load resistance and the duty cycle of the switching signal. The equation is sufficient for an ideal converter but can lead to incorrect results for a real converter, which naturally features some parasitic resistances. The goal of this study is to evaluate how the parasitic resistances of a converter influence its input resistance and if they are relevant in terms of MPPT system operation.

scholarly journals Can a Semi-Active Energy Harvesting Shock Absorber Mimic a Given Vehicle Passive Suspension?

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4378
Author(s):  
Jorge A. Reyes-Avendaño ◽  
Ciro Moreno-Ramírez ◽  
Carlos Gijón-Rivera ◽  
Hugo G. Gonzalez-Hernandez ◽  
José Luis Olazagoitia
Keyword(s):  
Energy Harvesting ◽  
Load Resistance ◽  
Ball Screw ◽  
External Energy ◽  
Shock Absorbers ◽  
Great Progress ◽  
Control Circuits ◽  
Minimum Velocity ◽  
Wasted Energy ◽  
At Will

Energy harvesting shock absorbers (EHSA) have made great progress in recent years, although there are still no commercial solutions for this technology. This paper addresses the question of whether, and under what conditions, an EHSA can completely replace a conventional one. In this way, any conventional suspension could be replicated at will, while recovering part of the wasted energy. This paper focuses on mimicking the original passive damper behavior by continuously varying the electrical parameters of the regenerative damper. For this study, a typical ball-screw EHSA is chosen, and its equivalent suspension parameters are tried to be matched to the initial damper. The methodology proposes several electrical control circuits that optimize the dynamic behavior of the regenerative damper from the continuous variation of a load resistance. The results show that, given a target damper curve, the regenerative damper can adequately replicate it when there is a minimum velocity in the damper. However, when the damper velocity is close to zero, the only way to compensate for inertia is through the introduction of external energy to the system.

Modeling and Analysis of Grid-Connected Inverter for PV Generation

2013 ◽  
Vol 760-762 ◽  
pp. 451-456 ◽  
Author(s):  
Neng Cao ◽  
Ya Jun Cao ◽  
Jiao Yu Liu
Keyword(s):  
Control System ◽  
Power Quality ◽  
High Speed ◽  
Control Algorithm ◽  
Maximum Power ◽  
Maximum Power Point ◽  
Incremental Conductance ◽  
Conductance Method ◽  
Power Point ◽  
Pv Generation

In order to improve the efficiency of photovoltaic generation as well as the power quality, grid-connected inverters for PV generation research was carried out for photovoltaic maximum power point tracking. Based on some current studies on the incremental conductance method, an advanced incremental conductance control algorithm was proposed, which can track maximum power point rapidly and accurately. The oscillation phenomenon, which exists near the maximum power point, was improved at a great extent, so to the efficiency of photovoltaic cells generation electricity. The inverter control system has an advantage in its high speed and flexibility by applying advanced control algorithm. And the source harmonic current is remarkably reduced. In addition, the power factor is enhanced and the power quality is improved. Finally, according to the principle of inverter control system and based on the analysis on the mathematical model of photovoltaic inverter, a simulation model of that is established based on MATLAB/SIMULINK.

scholarly journals RF-MEMS Monolithic K and Ka Band Multi-State Phase Shifters as Building Blocks for 5G and Internet of Things (IoT) Applications

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2612 ◽  
Author(s):  
Jacopo Iannacci ◽  
Giuseppe Resta ◽  
Alvise Bagolini ◽  
Flavio Giacomozzi ◽  
Elena Bochkova ◽  
...  
Keyword(s):  
Internet Of Things ◽  
Communication Systems ◽  
High Speed ◽  
Phase Shifter ◽  
Satellite Communication ◽  
Rf Mems ◽  
Building Blocks ◽  
Phase Shifters ◽  
Small Cells ◽  
Mems Technology

RF-MEMS, i.e., Micro-Electro-Mechanical Systems (MEMS) for Radio Frequency (RF) passive components, exhibit interesting characteristics for the upcoming 5G and Internet of Things (IoT) scenarios, in which reconfigurable broadband and frequency-agile devices, like high-order switching units, tunable filters, multi-state attenuators, and phase shifters will be necessary to enable mm-Wave services, small cells, and advanced beamforming. In particular, satellite communication systems providing high-speed Internet connectivity utilize the K and Ka bands, which offer larger bandwidth compared to lower frequencies. This paper focuses on two design concepts of multi-state phase shifter designed and manufactured in RF-MEMS technology. The networks feature 4 switchable stages (16 states) and are developed for the K and Ka bands. The proposed phase shifters are realized in a surface micromachining RF-MEMS technology and the experimentally measured parameters are compared with Finite Element Method (FEM) multi-physical electromechanical and RF simulations. The simulated phase shifts at both the operating bands fit well the measured value, despite the measured losses (S21) are larger than 5–7 dB if compared to simulations. However, such a non-ideality has a technological motivation that is explained in the paper and that will be fixed in the manufacturing of future devices.

Ferrite Properties and Technology Issues for Improved Microwave Systems

2004 ◽  
Vol 833 ◽  
Author(s):  
Gerald F. Dionne ◽  
Daniel E. Oates
Keyword(s):  
High Speed ◽  
Uniaxial Anisotropy ◽  
Phase Shifters ◽  
Microwave Device ◽  
Low Loss ◽  
High Q ◽  
Magnetic Components ◽  
Ferrite Material ◽  
Tunable Resonators ◽  
Propagation Properties

ABSTRACTMicrowave device engineers continually seek materials advances to improve performance of magnetic components at reduced size and cost. Wherever possible, microstrip or stripline device configurations are adopted in preference to bulky waveguide structures. In radar and communications applications, the nonreciprocal propagation properties of ferrites are essential for realizing phase shifters, circulators, isolators, and power limiters. The introduction of superconductor circuits has led to the development of very low-loss phase shifters and circulators. Recent demonstrations of tuning reciprocal rf permeability by varying the state of magnetization at very low magnetic fields has led to the development of high-speed, high-Q tunable filters. In this paper, design issues of four classes of microwave device are reviewed from the standpoint of their ferrite material requirements: (1) low-loss microstrip phase shifters (2) microstrip tunable resonators, (3) self-biased microstrip circulators with normal or in-plane uniaxial anisotropy, and (4) high-power quasi-optical circulators.

The Research on Phantom-Bit Technology of Digital Phase Shifters for Satellite Tracking System of Phase Array

2014 ◽  
Vol 644-650 ◽  
pp. 4555-4558
Author(s):  
Chao Hai Li ◽  
Wen Xian Jiang ◽  
Guo Long Wang
Keyword(s):  
High Speed ◽  
Phased Array ◽  
Tracking System ◽  
Correlation Method ◽  
Digital Signal ◽  
Satellite Tracking ◽  
Phase Shifters ◽  
Phase Array ◽  
Satellite Platform ◽  
Beam Displacement

Phased array satellite platform self-tracking system is for the stability between the missiles and other high-speed movement of the platform and the relay satellite two-way information transmission needs to carry out the self-tracking technology research of onboard platform-dimensional active phased array satellite. The system uses a sub-array correlation method for accurate measurement of the angle of the satellite signal. Receiving array is divided into four 4 * 4 sub-array, each antenna signal combining unit 4 sub array for 4-way A / D to be converted, through down-conversion, filtering, extraction and other processes to get a digital baseband signal, the baseband digital signal processing is to extract the angle error information into digital beam orientation system for tracking filtering operation, thereby ensuring that the transceiver has been aligned with the satellite antenna beam direction. In this paper ,phantom-bit technology for satellite tracking system under the condition of minimum beam displacement is researched for satellite tracking system.

On electrical optimisation using a Duffing-type vibrational energy harvester

2014 ◽  
Vol 229 (18) ◽  
pp. 3308-3319 ◽  
Author(s):  
Dongxu Su ◽  
Kimihiko Nakano ◽  
Rencheng Zheng ◽  
Matthew P Cartmell
Keyword(s):  
High Speed ◽  
Energy Harvester ◽  
Vibrational Energy ◽  
Electrical Power ◽  
Low Frequency ◽  
Load Resistance ◽  
Ball Screw ◽  
Response Analysis ◽  
Practical Implementation ◽  
Maximum Displacement

There has been much recent interest in the response analysis and optimisation of the linear energy harvester under ambient vibrations. To transfer maximum power to an electrical load in a resonant system, the load resistance should be equal to the sum of the electrical analogue of mechanical damping and internal resistance. However, principally because of the limited bandwidth offered by the linear energy harvester, the potential benefit of nonlinearity has recently been applied to improve the effectiveness of energy harvesting devices. For example, a Duffing-type oscillator can provide a wider bandwidth and greater effectiveness when subject to periodic excitations. The motivating hypothesis has been that the nonlinear Duffing energy harvester can also be optimised to maximise the available electrical power. This paper presents theoretical optimisation and numerical studies under three different conditions with the designed Duffing-type devices. First, the simplest model without any transmission mechanism and optimisation constraints is considered. Second, a device operated under low frequency and large force excitations using a ball screw to convert low-speed linear motion to high-speed rotation is analysed, where the optimum lead and load resistance are derived. Finally, considering the limitation of some dimensions in practical implementation, the constrained optimisation subjected to the maximum displacement of the seismic mass is also shown in this paper.

High Speed Contact Type Linear Sensor Array Using a-Si pin Diodes

1983 ◽  
Author(s):  
H. Yamamoto ◽  
T. Baji ◽  
H. Matsumaru ◽  
Y. Tanaka ◽  
K. Seki ◽  
...  
Keyword(s):  
High Speed ◽  
Sensor Array ◽  
Pin Diodes ◽  
Contact Type
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