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Wideband receiver (RX) and transmitter (TX) RF front-ends for wireless universal radio applications are presented. The RX is comprised of a two-stage low-noise amplifier (LNA) applying feedback and shunt peaking, a combiner buffer for performance boosting, and an inverter-based in-phase/quadrature (IQ) down-conversion mixer. The wideband LNA provides input matching of better than -\ 10 dB from dc to beyond 10 GHz. The conversion gain (CG) of the RX front-end has a peak value of 31 dB with a 3-dB bandwidth up to 9 GHz. The minimal noise figure is 6 dB and kept below 9 dB within the entire operational bandwidth. The RX has a linearity in terms of intermodulation distortion of better than -\12 dBm. The direct conversion TX involving inverter-based IQ modulator and Darlington-type pre-power amplifier features operation up to 9 GHz with 10-dB mean CG and an average output power of 4 dBm at 1-dB compression level. Excluding buffers and local oscillator generation, the RX and TX dissipate 54 and 84 mW, respectively, from a 1.2-V voltage supply. The circuit prototypes have been fabricated in a standard 65-nm CMOS low-power process without any additional RF options and occupy an area of only 0.77 \ mm^2 and 0.53 \ mm^2, respectively. [ABSTRACT FROM PUBLISHER]

This paper examines the differences in large signal mixed-mode scattering parameter characterization of differential amplifiers arising from virtual and true differential probing. The analysis is carried out by means of differential gain compression curves obtained from exemplary amplifier test assemblies with variable common mode rejection ratio. Based on analytical derivations involving basic nonlinear circuit theory, mathematical closed form transfer functions of these amplifiers are presented that enable an a-priori estimation of the occuring measurement error. Numerical simulations complete the theoretical investigations by giving additional physical insights onto the individual amplifier nodal voltages effecting the compression. Experimental results obtained from true and virtual differential compression curve measurements of the considered amplifier topologies are finally compared to the results gained from the theoretical considerations. Based on these results, the reason for the deviation between virtual and true differential measurements is addressed and upper and lower bounds for these deviations are given that are in accordance with the results reported in literature. [ABSTRACT FROM AUTHOR]

This paper presents the design and implementation of a low power wideband mixer for multistandard receivers, covering global system for mobile communications, universal mobile telecommunications system, wireless local area network, Bluetooth, and ultra-wideband. The circuit topology is based on the folded technique with a current reuse shunt feedback RF input stage operating at a low supply voltage of 1 V. The mixer offers a peak gain of 12.8 dB, a 3-dB bandwidth from 1 to 10.5 GHz, and a minimum double-sideband noise figure of 7.6 dB. The input referred compression point is better than -15 dBm with an output referred intercept point of better than 5.75 dBm over the entire bandwidth. The mixer circuit was fabricated in a 65-nm standard CMOS process and draws 5 mA of dc current, leading to a power dissipation of only 5 mW. Gain and noise performance can be further increased when operating at nominal supply voltage of 1.2 V at the expense of an increasing power dissipation. [ABSTRACT FROM AUTHOR]