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Abstract: This letter presents a single CDTA (Current Differencing Transconductance Amplifier)-based current-mode quadrature oscillator (QO). The proposed circuit structure is very simple, which only consists of one CDTA, one resistor and two capacitors, and it is easy for monolithic integration. The oscillation frequency of the QO can be electronically controlled by the bias current of the CDTA. Moreover, the oscillator can provide two quadrature current outputs. PSPICE simulation results are provided to verify all the theoretical analysis. [Copyright &y& Elsevier]

Abstract: A new low complexity ultra-wideband 3.1–10.6GHz low noise amplifier (LNA), designed in a chartered 0.18μm RFCMOS technology, is presented in this paper. The ultra-wideband LNA only consists of two simple amplifiers with an inter-stage inductor connected. The first stage utilizing a resistive current reuse and dual inductive degeneration techniques is used to attain a wideband input matching and low noise figure. A common source amplifier with inductive peaking technique as the second stage achieves high flat gain and wide the −3dB bandwidth of the overall amplifier simultaneously. The implemented ultra-wideband LNA presents a maximum power gain of 15.6dB, a high reverse isolation of −45dB and a good input/output return losses are better than −10dB in the frequency range of 3.1–10.6GHz. An excellent noise figure (NF) of 2.8–4.7dB was obtained in the required band with a power dissipation of 14.1mW under a supply voltage of 1.5V. An input-referred third-order intercept point (IIP3) is −7.1dBm at 6GHz. The chip area including testing pads is only 0.8mm×0.9mm. [Copyright &y& Elsevier]

Abstract: This paper proposes a new current-mode current-controlled single input multiple output (SIMO) type universal filter. The proposed circuit employs two current-controlled current conveyors (CCCIIs), one MO-CCCA (current-controlled current amplifier with multi-outputs) and two grounded capacitors. The filter can simultaneously realize lowpass, bandpass, highpass, bandstop and allpass filter outputs, and offers an independent electronic control of the natural angular frequency () and quality factor (Q) by means of adjusting the bias currents of the CCCIIs. The parameter sensitivities are small. Moreover, a high Q-value filter can be easily obtained by adjusting the ratio of two bias currents of MO-CCCA. PSPICE simulation results are given to demonstrate the advantages of the proposed circuit. [ABSTRACT FROM AUTHOR]

Abstract: An improved design of 860–960MHz fully integrated CMOS power amplifier (PA) for UHF RFID transmitter is presented in this paper. It utilizes three stage differential structure, including common-source structure applying RC feedback circuit to improve linearity, cascade structure adopting self-biased cascode technique and self-forward-body-bias (SFBB) technique to overcome shortcomings of low breakdown voltage and to reduce supply voltage respectively in order to obtain high output power, high efficiency and low supply voltage. By integrating these techniques organically, simulation results demonstrate that the circuit provides 21dBm output power and 35% power-added efficiency (PAE) with 3V supply. A comparison with other PAs operating in similar frequencies shows the proposed LNA has advantages of higher output power, higher PAE, higher linearity and lower supply voltage. [Copyright &y& Elsevier]

Surrogate-based optimization has been widely used in analog circuit sizing. Surrogate-based optimization efficiency in a parallel computing environment has become an emerging problem. In this paper, a surrogate-based parallel optimization of analog circuits using multi-acquisition functions (SPMA) is proposed. The Surrogate Model-Aware Search Mechanism (SMAS) is used as the basis. Under the SMAS framework, modeling and search are concentrated in promising areas. The probability of improvement (PI), expected improvement (EI), and lower confidence bound (LCB) combined in the multi-acquisition function each balance exploration and exploitation in its own way. It is necessary to configure enough training data points for the local model constructed in the promising area to improve the exploration ability of the multi-acquisition functions. Multiple mutation operations are used to provide more promising candidate designs and increase the probability that the surrogate model can prescreen to the optimal solutions. SPMA combines the advantages of multi-acquisition functions and multiple mutation operations, and has been verified by a two-stage amplifier and a three-stage amplifier, as well as three well-known benchmark functions. The optimization results show that SPMA is superior to state-of-the-art methods in terms of efficiency and effectiveness. [ABSTRACT FROM AUTHOR]