Cascade amplifier

About: Cascade amplifier is a research topic. Over the lifetime, 5478 publications have been published within this topic receiving 64182 citations.

A compact power-efficient 3 V CMOS rail-to-rail input/output operational amplifier for VLSI cell libraries

Abstract: This paper presents a two-stage, compact, power-efficient 3 V CMOS operational amplifier with rail-to-rail input and output ranges. Because of its small die area of 0.04 mm/sup 2/, it is very suitable as a VLSI library cell. The floating class-AB control is shifted into the summing circuit, which results in a noise and offset of the amplifier which are comparable to that of a three stage amplifier. A floating current source biases the combined summing circuit and the class-AB control. This current source has the same structure as the class-AB control which provides a power-supply-independent quiescent current. Using the compact architecture, a 2.6 MHz amplifier with Miller compensation and a 6.4 MHz amplifier with cascoded-Miller compensation have been realized. The opamps have, respectively, a bandwidth-to-supply-power ratio of 4 MHz/mW and 11 MHz/mW for a capacitive load of 10 pF. >

Method and apparatus for operating a radio-frequency power amplifier as a variable-class linear amplifier

Abstract: A variable-class linear amplifier (600, 800, 900) applies a supply type of envelope modulation to an RF power amplifier operating in or near compression at highest envelope amplitudes, and transitions gradually to an envelope tracking type of operation at intermediate envelope amplitudes. The amplifier further transitions gradually to a linear class of operation with a constant supply voltage (508) at lowest envelope amplitudes.

Microwave transistor amplifier

Abstract: A low noise, multistage microwave transistor amplifier constructed using microwave integrated circuit techniques is disclosed. The illustrated embodiment is a two-stage transistor amplifier which is the basic building block for broadband, high-gain cascades. This amplifier features an interstage network consisting of a very short transmission line which minimizes the size and frequency dependence of the amplifier. This is achieved in the satellite communications band of 3.7 to 4.2 GHz by constructing the amplifier on a suitably low dielectric constant substrate rather than the usual high dielectric constant substrates used in microwave amplifier applications.

A 1.75-GHz polar modulated CMOS RF power amplifier for GSM-EDGE

Abstract: This work presents a fully integrated linearized CMOS RF amplifier, integrated in a 0.18-/spl mu/m CMOS process. The amplifier is implemented on a single chip, requiring no external matching or tuning networks. Peak output power is 27 dBm with a power-added efficiency (PAE) of 34%. The amplitude modulator, implemented on the same chip as the RF amplifier, modulates the supply voltage of the RF amplifier. This results in a power efficient amplification of nonconstant envelope RF signals. The RF power amplifier and amplitude modulator are optimized for the amplification of EDGE signals. The EDGE spectral mask and EVM requirements are met over a wide power range. The maximum EDGE output power is 23.8 dBm and meets the class E3 power requirement of 22 dBm. The corresponding output spectrum at 400 and 600 kHz frequency offset is -59 dB and -70 dB. The EVM has an RMS value of 1.60% and a peak value of 5.87%.