Category: Electronic Tutorial

IMPATT Diode: IMPATT is an acronym for impact ionization avalanche transit time. The theory of this device was presented in 1958, and the first experiment diode was described in 1965. The basic structure of a silicon pn-junction IMPATT diode, from the semiconductor point of view, is identical to that of varactor diodes. The important difference between IMPATT and varactor diodes are in their modes of operation and in thermal design. Figure 1 shows a typical dc current versus voltage (I-V) characteristic for a pn-junction diode. In the forward-bias direction, the current increases rapidly…

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A parametric amplifier provides amplification via the variation of a reactance. This reactance is a parameter of a tuned circuit – thus the amplifier’s name. Consider a LC tank circuit that is oscillation at some microwave frequency. If the capacitor’s plates are pulled apart at the instant of time that the voltage across them is maximum  positive, work has been accomplished. Since the capacitance, C, has been decreased and the charge, q, must remain the same, the voltage across the capacitor, V, must have been increased since V = q/C.…

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The are various applications of microwaves or we can say the application of microwaves can be broadly classified because of their use in various fields including cooking, long ranger communications, etc. The foundation of modern electronics and communications environment using radio frequency (RF) and microwaves were laid in the nineteenth century, named after Michael Faraday’s observations of magnetic field on light propagation in 1845, and James C Maxwell’s derivation of four basic equations of the electromagnetic theory of light. Because of the short physical wavelength of these frequencies, they present…

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