This paper discusses the effect of load change on the Thevenin equivalent impedance of power systems. In this paper, the Thevenin equivalent impedance influenced by the derivative of active load with respect to reactive load (dP/dQ) is analyzed. The Thevenin equivalent impedance forms a closed curve in a complex plane and shrinks to one point when voltage collapses. The magnitude of the Theveni...

Owing to its well-known properties of possible power-noise match as well as superior noise performance, the inductively-degenerated low-noise amplifier is nowadays the most-widely used RF pre-amplifier topology. However, there is not much flexibility when setting the amplifier’s input impedance to match the source impedance, as for a given biasing condition, matching is achievable only for a pa...

Owing to its well-known properties of possible power-noise match as well as superior noise performance, the inductively-degenerated low-noise amplifier is nowadays the most-widely used RF preamplifier topology. However, there is not much flexibility when setting the amplifier’s input impedance to match the source impedance, as for a given biasing condition, matching is achievable only for a par...

A new cascadable CMOS based voltage squarer circuit having voltage input/current output and its analog four-quadrant multiplier application are presented. The proposed structure has high input impedance and high output impedance; thus, it can be easily connected to other circuits without requiring any extra buffers. Moreover, its two symmetrical bias voltages have high input impedances; accordi...

The general utility of the operational amplifier is derived from the fact that it is intended for use in a feedback loop whose feedback properties determine the feed-forward characteristics of the amplifier and loop combination. To suit it for this usage, the ideal operational amplifier would have infinite input impedance, zero output impedance, infinite gain and an open-loop 3 dB point at infi...

The challenge in designing a broadband microwave amplifier is the fact that the input impedance at lower frequencies is practically an open circuit, and at higher frequencies predominantly capacitive and can be almost a short. This makes broadband matching difficult. For example, the TriQuint device we used for the project has an input impedance that is practically an open circuit at 0.1GHz, is...

We study the matching characteristics of a rectangular slot located in the farthest upper part of a ground plane. First, we investigate the effect of geometrical parameters including the length and width of the slot, the ground plane height, and feed point position on the input impedance. In turn, we consider the matching between the slot and a 50 feed and examine impedance-matched frequencies ...

The in-process changes of weld nugget growth during the Resistance Spot Welding were investigated based on the resistance of input electrical impedance. To compute the time varying resistance of input electrical impedance, the welding voltage and current signals are measured simultaneously and then converted into complex-valued signals by using Hilbert transform. Comparing with the dynamic cont...

The general utility of the operational amplifier is derived from the fact that it is intended for use in a feedback loop whose feedback properties determine the feed-forward characteristics of the amplifier and loop combination. To suit it for this usage, the ideal operational amplifier would have infinite input impedance, zero output impedance, infinite gain and an open-loop 3 dB point at infi...