Topic
Output impedance
About: Output impedance is a research topic. Over the lifetime, 11185 publications have been published within this topic receiving 134949 citations.
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Patent•
28 Sep 2000
TL;DR: In this paper, a back-off power level is achieved by increasing the load resistance of the amplifier at the reduced output power level as compared to load impedance at a higher power level including full operating power.
Abstract: Efficiency of an RF/microwave power amplifier is increased at a back-off power level by increasing the load resistance of the amplifier at the reduced output power level as compared to load impedance at a higher power level including full operating power. The different load impedances can be realized with two amplification units in parallel each having different load impedances. Alternatively, a single amplification path can be provided with an output impedance matching network which is selectively bypassed for increased impedance load during back-off power operation. In another embodiment, the output impedance matching network can include a shunt inductance which is selectively switched into the network to increase impedance for back-off power operation.
60 citations
TL;DR: In this paper, the authors derived the dynamic impedance of a x-Si PV module in the dark with five reverse bias voltages and over a frequency range of 1 Hz to 60 kHz.
60 citations
Patent•
03 Aug 1978
TL;DR: In this article, a single phase, two or multi-pole alternator with stationary field coils, and a rotating armature is provided, and an external trigger switch is adapted to be closed at the appropriate time to create the desired output current from said alternator to an external load circuit, and as the output current passes through zero a self-commutating effect is provided to disconnect the generator from the external circuit.
Abstract: This invention relates to an electromechanical energy converter with inertial energy storage. The device, a single phase, two or multi-pole alternator with stationary field coils, and a rotating armature is provided. The rotor itself may be of laminated steel for slower pulses or for faster pulses should be nonmagnetic and electrically nonconductive in order to allow rapid penetration of the field as the armature coil rotates. The armature coil comprises a plurality of power generating conductors mounted on the rotor. The alternator may also include a stationary or counterrotating compensating coil to increase the output voltage thereof and to reduce the internal impedance of the alternator at the moment of peak outout. As the machine voltage rises sinusoidally, an external trigger switch is adapted to be closed at the appropriate time to create the desired output current from said alternator to an external load circuit, and as the output current passes through zero a self-commutating effect is provided to allow the switch to disconnect the generator from the external circuit.
60 citations
TL;DR: This study presents four new voltage mode first-order all-pass filters using a newly developed single Dual-X current conveyor with buffered output using PSPICE simulations, which show good agreement to theoretical anticipations.
Abstract: This study presents four new voltage mode first-order all-pass filters using a newly developed single Dual-X current conveyor with buffered output. The proposed circuits possess high-input impedance, low-output impedance and require either two or three passive elements. An application of new circuits is also given in realising the quadrature oscillator. Non-ideal and sensitivity analysis is also performed. The circuit performances are depicted through PSPICE simulations, which show good agreement to theoretical anticipations. Possible realisation using AD-844 along with some experimental results are also given for completeness sake. The new circuits are expected to enhance the already-existing knowledge on the subject.
60 citations
TL;DR: In this paper, a permittivity-tunable electret composite film, i.e., a thermoplastic polyurethane (TPU) matrix with polyethylene glycol (PEG) additives and polytetrafluoroethylene (PTFE) nanoparticle inclusions, is employed as the triboelectric layer.
Abstract: Triboelectric nanogenerators (TENGs), which hold great promise for sustainably powering wearable electronics by harvesting distributed mechanical energy, are still severely limited by their unsatisfactory power density, small capacitance, and high internal impedance. Herein, a materials optimization strategy is proposed to achieve a high performance of TENGs and to lower the matching impedance simultaneously. A permittivity-tunable electret composite film, i.e., a thermoplastic polyurethane (TPU) matrix with polyethylene glycol (PEG) additives and polytetrafluoroethylene (PTFE) nanoparticle inclusions, is employed as the triboelectric layer. Through optimizing the dielectric constant of the composite, the injected charge density and internal capacitance of the TENG are significantly enhanced, thus synergistically boosting the output power and reducing the impedance of the TENG. The optimal output power reaches 16.8 mW at an external resistance of 200 kΩ, showing a 17.3 times enhancement in output power and a 90% decline in matching impedance. This work demonstrates a significant progress toward the materials optimization of a triboelectric generator for its practical commercialization.
60 citations