IEEE Transactions on Microwave Theory and Techniques · 2016 · 88 citations · 18 references
EngineeringElectrical EngineeringAnalog ElectronicsMicroelectronicsMicrowave EngineeringAnalog Integrated CircuitsCmos Circuit DesignMicrowave AmplifiersMixed-signal Integrated Circuit DesignRadio-frequency Integrated CircuitsSignal ConditioningAnalog Amplifier DesignBandwidthGainGain ControlLinear CharacteristicLinear RangeNoise FigureWideband Amplifiers
A higher frequency, over 2 GHz, is suggested for current 4G or 5G wideband applications. By adopting a unique gain control method, an analog-controlled variable-gain amplifier (VGA) with an accurate dB-linear characteristic is presented. The designed VGA not only features large bandwidth, but also has accurate gain adjustment with a relatively wide control voltage range. The VGA has a measured gain range of 24 dB, of which 17.3 dB is dB-linear with less than ±0.3-dB gain error. The -3-dB bandwidth is relatively constant from 2 to 2.2 GHz for the entire dB-linear range. An output 1-dB compression point of 1.8 dBm and a noise figure of 24 dB are measured. Due to the simple structure, the current consumption of the VGA core is only 2.9 mA from a 1.2-V supply, and the size is only 225 μm×45 μm, excluding pads. Moreover, the robustness of the designed VGA is verified by means of Monte Carlo simulation.
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