FET amplifier

About: FET amplifier is a research topic. Over the lifetime, 7048 publications have been published within this topic receiving 77549 citations.

High-frequency switching device with reduced harmonics

Abstract: According to one exemplary embodiment, a low harmonic switching device (200) includes a first switching block (202) including a first multi-gate FET (206), where the first switching block is coupled to a first input (262) and a shared output (270) of the low harmonic switching device. A first capacitor (214) is coupled between a first gate and a source of the first multi-gate FET and a second capacitor (216) is coupled between a second gate and a drain of the first multi-gate FET so as to cause a reduction in a harmonic amplitude in the shared output. A resistor (220) can couple the source to the drain of the first multi-gate FET. The first switching block can further include a second multi-gate FET (208), where a source of the second multi-gate FET is coupled to the drain of the first multi-gate FET and a drain of the second multi-gate FET is coupled to the shared output.

Sense amplifier for reduction of access device leakage

Abstract: A sense amplifier circuit includes first and second amplifier circuits. The first amplifier circuit includes a pair of cross-coupled transistors of a first channel type (e.g., N-channel FETs), and the second amplifier circuit includes a pair of cross-coupled transistors of a second channel type (e.g., P-channel FETs). The sense amplifier circuit also includes a third transistor of the second channel type coupled between first nodes of the first and second amplifier circuits, and a fourth transistor of the second channel type coupled between second nodes of the first and second amplifier circuits. The sense amplifier circuit reduces access device leakage of a DRAM cell during LRL refresh access, and improves refresh margin on a DRAM cell with a one written thereto. A method of reducing access device leakage and improving refresh margin using such an improved sense amplifier is also described.

Logarithmic amplifier with self-compensating gain for frequency range extension

Abstract: A progressive-compression logarithmic amplifier, amplifier stage, and method for increasing the bandwidth of a differential-input progressive-compression logarithmic amplifier are disclosed. The amplifier stage provides positive gain increases for decreases in the impedance of the load driven by the stage. When multiple amplifier stages of this type are cascaded, the gain increase in each stage compensates for high-frequency roll-off due to the input capacitance of the following stage. The compensating is activated by the roll-off effect itself, making the device self-compensating. This is preferably accomplished by providing a drive current sensing path that makes each node of the stage's differential output respond in opposition to the drive current drawn at the stage's other differential output--that is, an increase in drive current at one output node drops the voltage at the other output node.

Design, Measurement and Application of Lumped Elements up to J-Band

Abstract: Lumped-element design, fabrication and characterization has been extended for MIC requirements up to l8GHz. Spiral or loop inductors and overlay or interdigital capacitors have been measured at appropriate frequencies leading to satisfactory equivalent circuits. Variations in parasitic reactances and Q-factor with frequency, substrate dielectric constant and component geometry are presented. Particular applications include filter networks and FET amplifier matching circuits, the latter enabling octave coverage amplifier modules over X and J-band frequencies to be realised.

Variable gain amplifier having n parallel-connected elementary amplifiers

Abstract: A variable gain amplifier which has n parallel-connected elementary amplifiers, and components for selecting j-order (j=1, 2, . . . , n) elementary amplifier according to the desired gain. Each elementary amplifier is of a common base type. The variable gain amplifier includes components that are used to obtain a low value input impedance that is independent of the gain of the selected elementary amplifier. The variable gain amplifier will find particular application at the input stages of amplification lines of receiving circuits which require noise performance characteristics.