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A low-noise amplifier (LNA) design with the operation of concurrent dual-band for Global Navigation Satellite System (GNSS) receivers with single channel is presented in this work. This LNA structure has an inductively degenerated cascode architecture and is pseudo-differential, operating at two frequencies simultaneously (1.2 GHz and 1.57 GHz). Two noise reduction/cancellation techniques, using load capacitor and feedforward path, respectively, are proposed resulting in an excellent improvement in the noise figure (NF). The input matching circuit uses both series and parallel resonant components to enable concurrency. The adopted pseudo-differential structure results in input balun elimination. Inductively degenerated cascode topology provides both input impedance and optimum noise impedance matching. The soundness of the proposed approach has been demonstrated in a 0.18-µm CMOS technology by TSMC. Simulation results show that at 1.2 GHz and 1.57 GHz the LNA achieves −13 dB and −11 dB of input matching, 24.6 dB and 24.7 dB of gain, 1.47 dB and 1.43 dB of NF, respectively. The input-referred 1-dB compression point (IP1dB) is around −16 dBm, while the input-referred third-order intercept point (IIP3) achieves −2.2 dBm at 1.2 GHz and −0.6 dBm at 1.57 GHz. The LNA draws about 13 mA from a 1.8-V supply voltage. [ABSTRACT FROM AUTHOR]

This paper presents a lumped scalable model for spiral inductors in a radio frequency (RF) gallium nitride (GaN) technology on silicon substrate. The model has been developed by exploiting electromagnetic (EM) simulations of geometrically scaled spiral inductors. To this aim, the technology substrate, i.e., the metal back-end-of-line along with dielectric and semiconductor layers of the adopted GaN process, has been validated by means of experimental data and then used to define the EM simulator set-up for the spiral inductors. The proposed model adopts a simple π-topology with only seven lumped components and predicts inductor performance in terms of inductance, quality factor (Q-factor) and self-resonance frequency (SRF) for a large range of geometrical parameters of the spiral (i.e., number of turns, metal width, inner diameter). [ABSTRACT FROM AUTHOR]

The analysis and modeling of monolithic stacked transformers fabricated in a high-speed silicon bipolar technology is addressed. On-wafer experimental measurements are employed to investigate the effect of layout scaling on transformer performance parameters (i.e., self-resonance frequency, magnetic coupling coefficient, and insertion loss). Based on this analysis, a wideband lumped model is developed, whose parameters are related to layout and technological data through closed-form expressions. Model accuracy is demonstrated by comparing simulated and measured S-parameters, coil inductance, magnetic coupling coefficient, and maximum available gain of several transformers with scaled layout geometry. The self-resonance frequency is also employed as a figure-of-merit to demonstrate model accuracy at very high frequency. Index Terms--Integrated transformers, layout scaling, lumped modeling, on-wafer measurements, RF integrated circuits (ICs).

In this paper, a design methodology for the optimization of transformer-loaded RF circuits is presented. The optimization procedure is based on a novel figure of merit for the integrated transformer (namely the transformer characteristic resistance), which was introduced to quantify its performance when operated as a tuned load. Using the proposed approach, a highly linear up-converter for 5-GHz wireless LAN applications was implemented in a 45-GHz-[f.sub.T] SiGe HBT technology. The circuit achieved an output l-dB compression point of 4.5 dBm and a power gain of 18 dB, while drawing only 34 mA from a 3-V power supply. Index Terms--Figure of merit, integrated transformer, SiGe HBT, transformer characteristic resistance (TCR), tuned load, up-converter, wireless LAN (WLAN).

A lumped scalable model for spiral inductors in silicon bipolar technology has been developed. The effect of three different cross sections on inductor performance was first investigated by comparing experimental measurements. Using both the results of this analysis and three-dimensional electromagnetic simulation guidelines, several circular inductors were integrated on a radial patterned ground shield for model validation purposes. The model employs a novel equation for series resistance with only one fitting parameter extracted from experimental measurements. All other model elements were related to technological and geometrical data by using rigorous analytical equations. The model was validated using one- and two-port measured performance parameters of 45 integrated inductors, and excellent agreement was found for all considered geometries up to frequencies well above self-resonance. Index Terms--Bipolar technology, integrated inductors, lumped model, patterned ground shield.