An integrated spectrum analyzer is useful for built-in self-test purposes, software-defined radios, or dynamic spectrum access in cognitive radio. The analog/RF performance is impaired by a number of ...factors, including thermal noise, phase noise, and nonlinearity. In this paper, we present an integrated circuit with two integrated RF-frontends, of which the outputs are crosscorrelated in digital baseband. We show by theory and measurements that the above-mentioned impairments are mitigated by this technique. The presented 65-nm CMOS prototype operates at 1.2 V, and obtains a noise floor below -169 dBm/Hz, an IIP 3 of +25 dBm, and more than 20 dB of phase-noise reduction. In a special high-impedance mode, an even lower noise floor below -172 dBm/Hz is obtained.
Evasion of apoptosis is critical for the development and growth of tumors. The pro-survival protein myeloid cell leukemia 1 (Mcl-1) is an antiapoptotic member of the Bcl-2 family, associated with ...tumor aggressiveness, poor survival, and drug resistance. Development of Mcl-1 inhibitors implies blocking of protein-protein interactions, generally requiring a lengthy optimization process of large, complex molecules. Herein, we describe the use of DNA-encoded chemical library synthesis and screening to directly generate complex, yet conformationally privileged macrocyclic hits that serve as Mcl-1 inhibitors. By applying a conceptual combination of conformational analysis and structure-based design in combination with a robust synthetic platform allowing rapid analoging, we optimized
potency of a lead series into the low nanomolar regime. Additionally, we demonstrate fine-tuning of the physicochemical properties of the macrocyclic compounds, resulting in the identification of lead candidates
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with a balanced profile, which are suitable for future development toward therapeutic use.
Hard-switched mixers have attractive linearity and noise properties, but are plagued by spurious responses due to the harmonic content of square-wave local oscillator (LO) signals. Harmonic rejection ...mixers (HRMs) reject (some of) these responses and can be constructed combining polyphase mixing and amplitude weighting. This brief presents a generalized model for the analysis of the harmonic rejection (HR) of such HRMs, based on circular convolution. We show that the effective LO signal can be modeled as a periodic Dirac impulse filtered by a time-discrete filter. For a multi-stage HR system, this filter consists of multiple stages as well, and the coefficients of each stage can be found simply by inspection. The total HR is shown to be the sum (in dB) of the rejection of the individual filtering stages, highly simplifying analysis and design of HRMs.
Spurious-Free Dynamic Range of a Uniform Quantizer Oude Alink, M.S.; Kokkeler, A.B.J.; Klumperink, E. ...
IEEE transactions on circuits and systems. II, Express briefs,
06/2009, Letnik:
56, Številka:
6
Journal Article
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Quantization plays an important role in many systems where analog-to-digital conversion and/or digital-to-analog conversion take place. If the quantization error is correlated with the input signal, ...then the spectrum of the quantization error will contain spurious peaks. Although analytical formulas describing this effect exist, numerical evaluation can take much effort. This brief provides approximations for the spurious-free dynamic range (SFDR) of a uniform quantizer with a single sinusoidal input, with and without additive Gaussian noise. It is shown that the SFDR increases by approximately 8 dB/bit, in case there is no noise. Generalizing this result to multitone inputs results in an additional 2 dB/bit per additional tone. Additive Gaussian noise decorrelates the sinusoid(s) and the quantization error, which results in a dramatic increase in SFDR.
This article presents a multi-receiver cross-correlation technique for (B)FSK receivers, targeting wireless sensor network applications. Here, multiple receiver outputs are pair-wise cross-correlated ...and the correlated output samples are averaged to lower the noise floor at the receiver output. Compared to a two-receiver cross-correlation, multi-receiver cross-correlation generates more cross-correlated output samples in a given time. Hence it requires a shorter measurement time for a desired noise floor reduction and facilitates a higher data rate for (B)FSK operation. Compared to a single receiver, it improves the linearity and the harmonic interferer tolerance using passive splitters and different LO frequencies in the receiver paths respectively. These theoretical insights are verified with measurements for the first time using a 2- and 3-receiver cross-correlation in a BFSK receiver. Operating at 1GHz and with a data rate of 200kbps, the demonstrator, using sub-mW mixer-first receiver front-ends for power efficiency, achieves −102dBm sensitivity and >40 dB rejection for both narrow and wideband harmonic interferers without any RF filters.
Abstract Presence of minimal residual disease (MRD), detected by flow cytometry, is an important prognostic biomarker in the management of B‐cell precursor acute lymphoblastic leukemia (BCP‐ALL). ...However, data‐analysis remains mainly expert‐dependent. In this study, we designed and validated an Automated Gating & Identification (AGI) tool for MRD analysis in BCP‐ALL patients using the two tubes of the EuroFlow 8‐color MRD panel. The accuracy, repeatability, and reproducibility of the AGI tool was validated in a multicenter study using bone marrow follow‐up samples from 174 BCP‐ALL patients, stained with the EuroFlow BCP‐ALL MRD panel. In these patients, MRD was assessed both by manual analysis and by AGI tool supported analysis. Comparison of MRD levels obtained between both approaches showed a concordance rate of 83%, with comparable concordances between MRD tubes (tube 1, 2 or both), treatment received (chemotherapy versus targeted therapy) and flow cytometers (FACSCanto versus FACSLyric). After review of discordant cases by additional experts, the concordance increased to 97%. Furthermore, the AGI tool showed excellent intra‐expert concordance (100%) and good inter‐expert concordance (90%). In addition to MRD levels, also percentages of normal cell populations showed excellent concordance between manual and AGI tool analysis. We conclude that the AGI tool may facilitate MRD analysis using the EuroFlow BCP‐ALL MRD protocol and will contribute to a more standardized and objective MRD assessment. However, appropriate training is required for the correct analysis of MRD data.
In this paper, we propose and analyze a pulse-output digital-to-frequency converter (DFC) generating square waves, which uses a digital-to-time converter (DTC) to correct the spurious tones (spurs) ...in the output spectrum. We focus on high-level architectural potential, discuss the design features of a DTC suitable for the proposed system, and explore possibilities and limits of this approach in terms of cleanness of the output spectrum. The behavioral model simulations confirm the theoretical analysis presented. Besides an analytical description of the output spurs, we derive a closed-form estimate of the worst-case spur, which leads to a simple design equation. This is useful to determine the DTC requirements number of bits and integral non-linearity (INL), given a certain spurious-free dynamic range (SFDR) target. We show that the maximum spur strength (in dBc) depends exclusively on the ratio between the output frequency and the clock frequency and the DTC features (number of bits, INL, and other impairments) and increases with the ratio by 6 dB/octave.
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