Abstract The backward Raman amplifier (RA) can considered as one of the best solutions for optical communication, especially in Wavelength Division Multiplexing technology. They reduce nonlinear effects, have low noise figure and a wide frequency range. work this paper aims to attenuation signal due its propagation fiber increase both gain output power. Two models are proposed. Proposal model c...

This paper reports the design of a highly-linear CMOS amplifier for Variable Gain Amplifier (VGA) applications. A better than –60dB 3rd harmonic distortion at differential output level of 1V peak-to-peak is obtained by utilizing a linearization scheme that does not rely on the active devices. The amplifier maintains 3dB bandwidth over 300MHz. A noise figure at 8.6dB is obtained with source impe...

This paper shows the results of research on the optical control of a GaAs chip monolithic amplifier, and is an extension of previous work by our group in the field of optical-microwave interaction [1-3]. The amplifier was originally designed for the transmitter stage of an indoor mobile communications system in the 2.4 GHz band. The possibilities of optical control of this amplifier are evidenc...

This paper presents a novel variable gain amplifier (VGA) design which is applied in the automatic gain control (AGC) loop of DVB-T/H receivers. The VGA composed of three cascaded tunable gain stages to provide a 70 dB dynamic range with 2 dB gain steps. Each gain stage is based on a digital variable gain amplifier (DVGA) which is composed of a plurality of gain blocks (GBs) and a fully differe...

A multistage operational transconductance amplifier with a feedforward compensation scheme which does not use Miller capacitors is introduced. The compensation scheme uses the positive phase shift of left-half-plane (LHP) zeroes caused by the feedforward path to cancel the negative phase shift of poles to achieve a good phase margin. A two-stage path increases further the low frequency gain whi...

The paper deals with the numerical and experimental development of single stage radio frequency (RF) amplifier with high gain for 2.4GHz receiver front-ends. The work is motivated by the increasing demand of high-gain receiver amplifier in low-cost especially for wireless local area network (WLAN) application. Prior hardware realization and experimental characterization, the proposed amplifier ...

An active-feedback frequency-compensation (AFFC) technique for low-power operational amplifiers is presented in this paper. With an active-feedback mechanism, a high-speed block separates the low-frequency high-gain path and high-frequency signal path such that high gain and wide bandwidth can be achieved simultaneously in the AFFC amplifier. The gain stage in the active-feedback network also r...

This work describes a 0.18μm CMOS implementation of an EEG acquisition system with programmable gain amplifier. Gain of the amplifier is digitally programmable from 35.09 dB to 62.55 dB by using 6 bits digital input. EEG input signals are of the range of few micro-voltage. Hence a high gain operational transconductance amplifier with gain of 62.83 dB is designed. Two 22:1 multiplexers with 5 se...

High-resolution electronic interface circuits for transducers with nonlinear capacitive impedance need an operational amplifier, which is stable for a wide range of load capacitance. Such operational amplifier in a conventional design requires a large area for compensation capacitors, increasing costs and limiting applications. In order to address this problem, we present a gain-boosted two-sta...