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Free, publicly-accessible full text available April 28, 2026
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A low-power and compact 3-bit active phase shifter is designed and implemented in a 22 nm FDSOI CMOS process. A modified inverter-based topology, which takes advantage of miller capacitance, is used to create a compact and low-power solution, resulting in 10 and 90 x reduction in the power and chip area, respectively, for a given phase shift, compared to the standard inverter-based topology. At the same time, the proposed phase shifter exhibits less sensitivity to device mismatch. The proposed design measures 0.004 mm2, consumes 1.8 mW, and delivers up to 65°of phase shift with RMS phase and amplitude error of 3.85°and ±0.34 dB, respectively. The measured die-to-die variation is also confined to ±6.2°, which is 10% of the full rangemore » « less
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Abstract We report the detection of the lowest-energy conformer of E -1-cyano-1,3-butadiene ( E -1- C 4 H 5 CN ), a linear isomer of pyridine, using the fourth data reduction of the GBT Observations of TMC-1: Hunting for Aromatic Molecules (GOTHAM) deep spectral survey toward TMC-1 with the 100 m Green Bank Telescope. We perform velocity stacking and matched-filter analyses using Markov chain Monte Carlo simulations and find evidence for the presence of this molecule at the 5.1 σ level. We derive a total column density of 3.8 − 0.9 + 1.0 × 10 10 cm −2 , which is predominantly found toward two of the four velocity components we observe toward TMC-1. We use this molecule as a proxy for constraining the gas-phase abundance of the apolar hydrocarbon 1,3-butadiene. Based on the three-phase astrochemical modeling code NAUTILUS and an expanded chemical network, our model underestimates the abundance of cyano-1,3-butadiene by a factor of 19, with a peak column density of 2.34 × 10 10 cm −2 for 1,3-butadiene. Compared to the modeling results obtained in previous GOTHAM analyses, the abundance of 1,3-butadiene is increased by about two orders of magnitude. Despite this increase, the modeled abundances of aromatic species do not appear to change and remain underestimated by one to four orders of magnitude. Meanwhile, the abundances of the five-membered ring molecules increase proportionally with 1,3-butadiene by two orders of magnitude. We discuss the implications for bottom-up formation routes to aromatic and polycyclic aromatic molecules.more » « less
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