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Gilbert Cell
In electronics, the Gilbert cell is a type of frequency mixer. It produces output signals proportional to the product of two input signals. Such circuits are widely used for frequency conversion in radio systems. The advantage of this circuit is the output Electric current, current is an accurate multiplication of the (differential) base currents of both inputs. As a mixer, its balanced operation cancels out many Parasitic oscillation, unwanted mixing products, resulting in a "cleaner" output. Gilbert cells can also be used as Variable-gain amplifier, variable-gain amplifiers (VGA). It is a generalized case of an early circuit first used by Howard Jones in 1963, invented independently and greatly augmented by Barrie Gilbert in 1967. It is a specific example of "translinear" design, a current-mode approach to analog circuit design. The specific property of this cell is that the differential output current is a precise Product (mathematics), algebraic product of its two differential ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Electronics
Electronics is a scientific and engineering discipline that studies and applies the principles of physics to design, create, and operate devices that manipulate electrons and other Electric charge, electrically charged particles. It is a subfield of physics and electrical engineering which uses Passivity (engineering), active devices such as transistors, diodes, and integrated circuits to control and amplify the flow of electric current and to convert it from one form to another, such as from alternating current (AC) to direct current (DC) or from analog signal, analog signals to digital signal, digital signals. Electronic devices have significantly influenced the development of many aspects of modern society, such as telecommunications, entertainment, education, health care, industry, and security. The main driving force behind the advancement of electronics is the semiconductor industry, which continually produces ever-more sophisticated electronic devices and circuits in respo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Frequency Mixers
Frequency is the number of occurrences of a repeating event per unit of time. Frequency is an important parameter used in science and engineering to specify the rate of oscillation, oscillatory and vibration, vibratory phenomena, such as mechanical vibrations, audio signals (sound), radio waves, and light. The interval of time between events is called the period. It is the Multiplicative inverse, reciprocal of the frequency. For example, if a heart beats at a frequency of 120 times per minute (2 hertz), its period is one half of a second. Special definitions of frequency are used in certain contexts, such as the angular frequency in rotational or cyclical properties, when the rate of angular progress is measured. Spatial frequency is defined for properties that vary or cccur repeatedly in geometry or space. The unit of measurement of frequency in the International System of Units (SI) is the hertz, having the symbol Hz. Definitions and units For cyclical phenomena ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
NE612
The NE612 is an integrated circuit for processing of signals, such as in the transmission of radio signals. It consists of an oscillator and a mixer. (122 kB) It can handle signal frequencies of up to 500 MHz and local oscillator frequencies of up to 200 MHz. The mixer is a “Gilbert cell” multiplier configuration which provides both a gain of 14 dB and a noise figure of at 45 MHz. The IC belongs to a family of the following ICs: NE602, SA602, NE612 and SA612. It is widely used in amateur radio applications, e.g. in the commercial Elecraft Elecraft, Inc. is an American manufacturer of amateur radio equipment and kits based in Watsonville, California. It was founded in 1998 by Wayne Burdick and Eric Swartz. The company's first product was the K2 transceiver, first prototyped i ... products, and others. References Linear integrated circuits Electronic oscillators {{Electronics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Cascode
The cascode is a two-stage amplifier that consists of a common emitter stage feeding into a common base stage when using bipolar junction transistors (BJTs) or alternatively a common source stage feeding a common gate stage when using field-effect transistors (FETs). Because there is no direct coupling from the output to input, the Miller effect is eliminated, contributing to a much higher bandwidth. Compared to a single amplifier stage, this combination may have one or more of the following characteristics: higher input–output isolation, higher input impedance, high output impedance, higher bandwidth (signal processing), bandwidth. History The use of a cascode (sometimes verbification, verbified to ''cascoding'') is a common technique for improving analog circuit performance, applicable to both vacuum tubes and transistors. The name "cascode" was coined in an article written by Frederick Vinton Hunt and Roger Wayne Hickman in 1939, in a discussion on the application of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Voltage-controlled Amplifier
A variable-gain (VGA) or voltage-controlled amplifier (VCA) is an electronic amplifier that varies its gain depending on a control voltage (often abbreviated CV). VCAs have many applications, including audio level compression, synthesizers and amplitude modulation. A crude example is a typical inverting op-amp configuration with a light-dependent resistor (LDR) in the feedback loop. The gain of the amplifier then depends on the light falling on the LDR, which can be provided by an LED (an optocoupler). The gain of the amplifier is then controllable by the current through the LED. This is similar to the circuits used in optical audio compressors. A voltage-controlled amplifier can be realised by first creating a voltage-controlled resistor (VCR), which is used to set the amplifier gain. The VCR is one of the numerous interesting circuit elements that can be produced by using a JFET (junction field-effect transistor) with simple biasing. VCRs manufactured in this way c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Bipolar Junction Transistor
A bipolar junction transistor (BJT) is a type of transistor that uses both electrons and electron holes as charge carriers. In contrast, a unipolar transistor, such as a field-effect transistor (FET), uses only one kind of charge carrier. A bipolar transistor allows a small current injected at one of its terminals to control a much larger current between the remaining two terminals, making the device capable of amplification or switching. BJTs use two p–n junctions between two semiconductor types, n-type and p-type, which are regions in a single crystal of material. The junctions can be made in several different ways, such as changing the doping of the semiconductor material as it is grown, by depositing metal pellets to form alloy junctions, or by such methods as diffusion of n-type and p-type doping substances into the crystal. The superior predictability and performance of junction transistors quickly displaced the original point-contact transistor. Diffused trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
International Journal Of Circuit Theory And Applications
''International Journal of Circuit Theory and Applications'' is a peer-reviewed scientific journal, published monthly by Wiley. It covers research on circuit theory and its applications on engineering problems, with a focus on electrical engineering. Its editor-in-chief is Ahmed El Wakil (University of Sharjah). Abstracting and indexing The journal is abstracted and indexed in: According to the ''Journal Citation Reports'', the journal has a 2023 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a type of journal ranking. Journals with higher impact factor values are considered more prestigious or important within their field. The Impact Factor of a journa ... of 1.8. References External links *{{official website, url=onlinelibrary.wiley.com/journal/1097007x Electrical and electronic engineering journals Monthly journals English-language journals Computational modeling journals Wiley (publisher) academic journals Academ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Transconductance
Transconductance (for transfer conductance), also infrequently called mutual conductance, is the electrical characteristic relating the current through the output of a device to the voltage across the input of a device. Conductance is the reciprocal of resistance. Transadmittance (or transfer admittance) is the AC equivalent of transconductance. Definition Transconductance is very often denoted as a conductance, , with a subscript, , for ''mutual''. It is defined as follows: : g_\text = \frac For small signal alternating current, the definition is simpler: : g_\text = \frac The SI unit for transconductance is the siemens, with the symbol S, as in conductance. Transresistance Transresistance (for transfer resistance), also infrequently referred to as mutual resistance, is the dual of transconductance. It refers to the ratio between a change of the voltage at two output points and a related change of current through two input points, and is denotated as : : r_\text = \ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Differential Amplifier
A differential amplifier is a type of electronic amplifier that amplifies the difference between two input voltages but suppresses any voltage common to the two inputs. It is an analog circuit with two inputs V_\text^- and V_\text^+ and one output V_\text, in which the output is ideally Proportionality (mathematics), proportional to the difference between the two voltages: : V_\text = A(V_\text^+ - V_\text^-), where A is the Gain (electronics), gain of the amplifier. Single amplifiers are usually implemented by either adding the appropriate feedback resistors to a standard Operational amplifier, op-amp, or with a dedicated integrated circuit containing internal feedback resistors. It is also a common sub-component of larger integrated circuits handling analog signals. Mathematics of the amplifier : V_\text = A_\text(V_\text^+ - V_\text^-), where V_\text^+ and V_\text^- are the input voltages, and A_\text is the differential gain. In practice, however, the gain is not quite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Frequency Mixer
In electronics, a mixer, or frequency mixer, is an electrical circuit that creates new frequencies from two signals applied to it. In its most common application, two signals are applied to a mixer, and it produces new signals at the sum and difference of the original frequencies. Other frequency components may also be produced in a practical frequency mixer. Mixers are widely used to shift signals from one frequency range to another, a process known as heterodyning, for convenience in transmission or further signal processing. For example, a key component of a superheterodyne receiver is a mixer used to move received signals to a common intermediate frequency. Frequency mixers are also used to modulation, modulate a carrier signal in Transmitter, radio transmitters. Types The essential characteristic of a mixer is that it produces a component in its output which is the product of the two input signals. Both active and passive circuits can realize mixers. Passive mixers use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
