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Special test structures emulating the performance of C-sensor, a direct floating gate (FG) ionizing radiation sensor, were used to investigate its degradation under Gamma radiation. Original MOS transistors with bulks made of crystalline silicon and Poly allowed minimizing the number of irradiations required to study the peculiarities of charge accumulation in the dielectrics of C-sensors. Electrical characterization of the developed structures before and after the exposure to different doses of Gamma radiation was performed. The guidelines for improving sensor immunity to radiation degradation are discussed. [ABSTRACT FROM AUTHOR]

Abstract: This work presents the application of a front-side maskless MEMS process to improve the performance of RF-CMOS transformers. High-frequency parasitic effects are much diminished, as oxide and substrate material are etched away. The passivated metal surface prevents damage to the transformer, and to other circuits, which use metal layers as self-aligned etch masks. Device self-resonant frequency was improved by 20%. At 18GHz, device quality factor rose from 0.5 to 6, and at 50GHz, maximum available gain was increased by 49%. The process''s low cost relative to other MEMS optimization methods with similar results makes this process attractive for the use of transformers in system-on-chip design. [Copyright &y& Elsevier]

Abstract: We present analysis, optimization, design and characterization of an integrated passive analog phase shifter at 24GHz in a commercially available 45nm RF-CMOS process. The design is based on a well-known RC bridge topology, which was optimized for maximum phase shift and minimal amplitude response variation versus phase and frequency. Phase is controlled by varying DC voltage on a varactor, resulting in 60° maximum phase shift with 0.1dB amplitude variation at 24GHz. The size of the phase shifter circuit excluding pads and input/output buffers is 40×50μm2. [Copyright &y& Elsevier]

Abstract: The paper presents the design and characterization of a low noise amplifier (LNA) in a 0.18μm CMOS process with a novel micromachined integrated stacked inductor. The inductor is released from the silicon substrate by a low-cost CMOS compatible dry front-side micromachining process that enables higher inductor quality factor and self-resonance frequency. The post-processed micromachined inductor is used in the matching network of a single stage cascode 4GHz LNA to improve its RF performance. This study compares performance of the fabricated LNA prior to and after post-processing of the inductor. The measurement results show a 0.5dB improvement in the minimum noise figure and a 1dB increase in gain, while good input matching is maintained. These results show that the novel low-cost CMOS compatible front-side dry micromachining process reported here significantly improves performance and is very promising for System-On-Chip (SOC) applications. [Copyright &y& Elsevier]

Abstract: A detailed time-domain analysis of noise due to thermal, 1/f and shot noise sources in CMOS active pixel sensors (APS) based on 3T and 4T pixel design is performed. We suggest that the conventional noise analysis based on the frequency domain, usually used for noise calculations of APS’s cannot be strictly applied, because the switched APS circuitry under study cannot be represented as a linear time-invariant system. To calculate explicit noise expressions for noise performance we, therefore, resort to time-dependent circuit models and perform time-domain noise analysis, taking into account the stationary nature of the various noise processes. To accomplish that, we divide the operation cycle of APS to separate time phases, and in these periods of time the relevant circuits can be modeled as linear time-invariant systems represented by simple (time-domain) impulse response functions. Finally, we present and compare between the noise simulation and noise measurement results for both 3T and 4T pixels. The excellent correspondence between the analytic expressions and the measured results corroborate the validity of the theoretical results. [Copyright &y& Elsevier]