On this signal path there are a pixel source follower, a switched-capacitor, noise-cancelling, variable-gain amplifier, and a correlated double sample (CDS) circuit in each column. Therefore, it is desirable to realize a low-power low-voltage VGA in CMOS technology. Figure 1: Variable Gain Amplifier (VGA) Applications . A variable-gain amplifier (VGA) is an important building block in wireless transceivers and it provides a constant receiver-output level for changing input power level due to varying inputs and interference. The first stage is a simple current amplifier while the second stage is an attenuator. Journal of Circuits, Systems, and Computers, 27, 1–18. The design adopts a new approximated exponential equation called the pseudo exponential equation to implement the dBlinear function. In this paper, a new pseudo-exponential function is described and a new CMOS exponential-control variable gain amplifier (VGA) based on the new function is introduced. Design of variable gain amplifier in CMOS technology @inproceedings{Liu2015DesignOV, title={Design of variable gain amplifier in CMOS technology}, author={H. Liu}, year={2015} } H. Liu; Published 2015; Engineering; 2015 i ACKNOWLEDGEMENTS I am deeply grateful to my supervisor, Associate Professor Boon Chirn Chye for giving me the opportunity to work in this project under his guidance. 41, No. 72–87 GHz) are less than 0.3 dB and 2.7°, respectively. A variable-gain or voltage-controlled amplifier 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. Foreword The research for this thesis was carried out in the Electronic Circuit Design Laboratory (ECDL) of Aalto University. The circuit uses a single operational amplifier, two resistors and a variable resistor. The bandwidt h of United States Patent 7358811 . This device is known as a variable gain amplifier (VGA), or programmable gain amplifier (PGA). The implemented phase‐inverting variable gain amplifier achieves 16 dB tuning range and 0.5 dB tuning step at 80 GHz. 1 , consists of a number of variable gain amplifier stages (cells) followed by a buffer to drive the load . A CMOS dB-linear variable gain amplifier (VGA) with a novel I/Q tuning loop for dc-offset cancellation is presented. In this paper a variable gain low noise amplifier (VG-LNA) is designed and analyzed for X band in 0.18 µm CMOS technology. Variable gain amplifier (VGA) is a vital building block for wireless communication systems. Moreover, the variable gain amplifier in the traditional column-parallel read-out circuit is merged into the front-end of the CTSD modulator. A low noise and relatively high dynamic range CMOS active pixel sensor (APS) using a variable-gain column amplifier is presented and analyzed. This letter presents for the first time the development of a variable gain CMOS phase shifter using 0.18 µm CMOS process in the S‐band frequencies to be integrated with conformal phased array beamforming antenna for smart communication radar applications. CrossRef Google Scholar Wideband CMOS variable gain amplifier The proposed variable gain amplifier VGA, as shown in Fig. A CMOS low-power digital variable gain amplifier design for a cognitive radio receiver “application for IEEE 802.22 standard”. About Variable Gain Amplifiers (RF VGA or DVGA) You can think of a variable gain amplifier for RF systems (RF VGA) as simply combining an amplifier (gain device) and an attenuator in the same package. Moreover, the variable gain amplifier in the traditional column-parallel read-out circuit is merged into the front-end of the CTSD modulator. 2, March, 2013, E-mail address: jes@aun.edu.eg The output voltage (V OP) half-circuit of the low-frequency small-signal model for the differential amplifier is shown in Fig. High Speed Variable Gain Amplifiers (VGAs) High frequency variable gain amplifiers (VGAs) must be fully specified not only in terms of traditional op amp ac specifications (bandwidth, slew rate, settling time), but also in terms of communications-specific specifications. A variable-gain or voltage-controlled amplifier is an electronic amplifier that varies its gain depending on a control voltage. Abstract A variable gain amplifier with a gain range of 15dB to ,4OdB and 80MHz bandwidth is describe bed here. Variable gain amplifier (VGA) is the key element for amplifying process in analog to digital converter (ADC). By programming the input resistance, the amplitude range of the input current can be tuned with 8 scales, which is equivalent to a traditional 2-bit preamplification function without consuming extra power and chip area. A variable gain amplifier architecture suitable for foundry CMOS is constructed using linearized transconductance blocks. The root mean square (RMS) gain and phase errors across −3 dB bandwidth (i.e. No multiplier is needed in the proposed approach. This type of circuit has many applications, including audio level compression, synthesizers and amplitude modulation. A CMOS high frequency variable gain amplifier with maximum high frequency operation and wide variable gain characteristics that is formed from an amplifier having a plurality of variable gain amplifier cells connected in series for continuously enabling wide gain variation; and a control voltage generator for generating and outputting the control voltage of the variable gain amplifier cells. T Index Terms- CMOS; Low-noise-amplifier (LNA); WiMAX. 577- 592 Journal of Engineering Sciences, Assiut University, Faculty of Engineering, Vol. An Inherently dB-linear All-CMOS Variable Gain Amplifier Ji-Wook Kwon and Seung-Tak Ryu Abstract—This paper introduces a simple variable gain amplifier (VGA) structure that shows an inherently dB-linear gain control property. The function of a VGA is to control the signal power level and maximize the dynamic range of the overall system. Abzugrenzen ist ein spannungsgesteuerter Verstärker von einem Analogmultiplizierer dadurch, dass es ein Steuersignal und ein verstärktes Signal gibt. The circuit is built in a standard CMOS process. The operational transconductance amplifier (OTA) is an amplifier whose differential input voltage produces an output current.Thus, it is a voltage controlled current source (VCCS). The proposed Ein Voltage Controlled Amplifier (VCA, engl. 2. By programming the input resistance, the amplitude range of the input current can be tuned with 8 scales, which is equivalent to a traditional 2-bit preamplification function without consuming extra power and chip area. The phase‐inverting variable gain amplifier consumes 8 mW at 1 V supply voltage. This combination, – Selectable PGA Gain: along with the device features, makes it ideal for a 20dB, 25dB, 27dB, 30dB variety of ultrasound systems. Adding the gain compensation circuit broadens gain dynamic range, and introducing the emitter degeneration capacitor broadens the bandwidth of a typical current … Additionally not only is the gain varied but also the sign. A device that utilizes digtial control is called a digital variable gain amplifier (DVGA). Such a device has a gain that is controlled by a dc voltage or, more commonly, a digital input. In this paper, the design of variable gain amplifier (VGA) for wireless receiver applications is presented. A CMOS variable-gain amplifier (VGA) using subthreshold exponential region transistors with master-slave control technique is proposed. Abstract: Provided is a complementary metal oxide semiconductor variable gain amplifier controlling a dB linear gain and a method of controlling the dB linear gain. CMOS variable gain amplifier for controlling dB linear gain . Using this circuit the gain can be calculated from the formula given above. I. L. Abdel-Hafez et al, High Linearity Cmos Variable Gain Amplifier For Uwb Applications, pp. The work presented in this thesis was part of a reseearch project funded by the European Space Agency (ESA). A binary control-word is used to control the gain of the variable gain amplifiers. Figure 3 is a diagram of the gain characteristics of an amplifier according to the present invetion. A 0.1–1GHz CMOS Variable Gain Amplifier Using Wideband Negative Capacitance Hangue PARK†a), Sungho LEE††, Nonmembers, Jaejun LEE ††, Member, and Sangwook NAM , Nonmember SUMMARY This Paper presents the design of a wideband variable gain amplifier (VGA) using 0.18µm standard CMOS technology. It can be realized by first creating a voltage-controlled resistor, which is used to set the amplifier gain. Variable gain op amp circuit. This thesis presents the design, simulation, layout and testing results for a dB-linear, high dynamic gain range CMOS variable gain amplifier (VGA). The VGA operates in current mode and includes two different stages. Figure 2 shows the circuit diagram of a logarithmic linear variable gain CMOS amplifier according to a preferred embodiment of this invention. The circuit simply uses a single variable gain amplifier. Requiring no additional components for dB-linear control, the structure is compact and power efficient. In the case of voltage-controlled VGAs, it is common to make the gain in dB proportional to a linear control voltage. The circuit embodies an inverse relationship between the gain and the control voltage. •Variable Gain Amplifier: consisting of a low-noise pre-amplifier (LNP) and a – Gain Control Range: 46dB variable-gain amplifier (VGA). The paper proposes a radio frequency front-end ultra-wideband variable gain amplifier (VGA) which is based on improved current-steering topology. 3. Keywords: wideband, variable gain amplifier, low noise amplifier, low power CMOS ii. The design is implemented in Tower Jazz 0.18 μm SiGe BiCMOS technology. A MOS device, operated in the linear region, is used as a shunt feedback element to vary the gain. für Spannungsgesteuerter Verstärker) ist ein elektronischer Verstärker, dessen Verstärkungsfaktor durch eine Steuerspannung gesteuert werden kann. 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