Impedance matching


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Related to Impedance matching: Impedance mismatch

Impedance matching

The use of electric circuits and devices to establish the condition in which the impedance of a load is equal to the internal impedance of the source. This condition of impedance match provides for the maximum transfer of power from the source to the load.

The maximum power transfer theorem of electric network theory states that at any given frequency the maximum power is transferred from the source to the load when the load impedance is equal to the conjugate of the generator impedance. When these conditions are satisfied, the power is delivered with 50% efficiency; that is, as much power is dissipated in the internal impedance of the generator as is delivered to the load. In general, the load impedance will not be the proper value for maximum power transfer. A network composed of inductors and capacitors may be inserted between the load and the generator to present to the generator an impedance that is the conjugate of the generator impedance (see illustration).

References in periodicals archive ?
The width and the length of the line used to calculate the effective dielectric constant have been chosen according to the dimensions of the impedance matching network, as will be seen in the next section.
4] produces better impedance matching at the lower resonant frequency.
62 GHz with acceptable performance in terms of AR, impedance matching and gain.
Common gate amplifier is used as it is easy to obtain input impedance matching.
40% reduction in peak clamping voltage -- 15-40% reduction in peak residual current -- 100 Ohm differential impedance matching with no external compensation required -- Straight through routing for improved layout -- Compact 16 pin TDFN package for reduced board space
In this case, the SILSP of the proposed antenna leads to a decrease in the height of the monopole and helps the impedance matching in a usable frequency band.
The AWL6152 module combines an InGaP HBT integrated circuit (IC) amplifier along with passive components to provide a low-cost solution that requires very few external components for biasing and none for RF impedance matching into a 50-Ohm system.
Support is also provided for active impedance matching circuits that ensure exact matching to any cable or device.
In previous design, external matching networks are used to achieve impedance matching for a broader band.
Among the various antenna configurations possible, the microstrip fed slot is particularly attractive due to the features like simpler design, low profile planar structure, wider bandwidth, bidirectional/omni-directional radiation patterns and increased degree of freedom for applying impedance matching techniques to get a wider bandwidth.
Packaged in miniature 3-mm x 6-mm dual-flat no leads (DFN) and standard small outline transistor (SOT-89) packages, MACOM's GaN in Plastic transistors operate at 50-V drain bias resulting in desirable power density and performance, high efficiency, and small impedance matching circuits due to improved device parasitics.
In [5], the author adopted microstrip line as an impedance transformer to realize impedance matching with 50 [OEMGA], and the transmission loss caused by the very narrow microstrip line has to be considered carefully.