https://scholar.dgist.ac.kr/handle/20.500.11750/47658 2026-04-04T20:25:32Z https://scholar.dgist.ac.kr/handle/20.500.11750/60118 Title: A Spectral-Efficient Low-Power NRZ/PAM-4 Dual-Mode Wireline Transmitter for Multidrop Interfaces Author(s): Kim, Donggeon; Gharibdoust, Kiarash; Tajalli, Armin; Lee, Kyoungtae; Kim, Gain Abstract: This paper presents a reconfigurable and energy-efficient digital spectrum shaping signaling (DSSS) for multidrop interfaces, where the output spectrum of the transmitted data is shaped using the 2-times repetitive block transmission to avoid frequency notches in the multidrop channel, thereby achieving a data rate up to 4x the first channel notch frequency. In conventional wireline transceivers (TRX), compensating for frequency notches requires a large number of decision feedback equalizer (DFE) taps at the receiver, resulting in significant area and power overhead. In contrast, the proposed DSSS architecture supports spectrum-efficient reconfigurable dual-mode NRZ/PAM4, reducing required equalization efforts and improving energy efficiency. The proposed scheme and its transmitter (TX) were first validated through event-driven behavioral simulations using XMODEL and verified with equipment-based measurements. Post-layout simulation results in 28nm CMOS process demonstrated 4 Gb/s data rate communicating over a channel having its first > 30 dB notch at 1 GHz, with a 235mV vertical eye opening and a TX energy efficiency of 0.39 pJ/b at 0.8V supply. 2025-08-07T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59341 Title: Triboelectric energy harvesting from rice paper/PDMS under extreme humidity environments Author(s): Panda, Swati; Hajra, Sugato; Bhosale, Premkumar Sharad; Belal, Mohamed Ahmed; Kaja, Kushal Ruthvik; Kim, Hoe Joon; Lee, Kyoungtae Abstract: A flexible and eco-friendly triboelectric nanogenerator (TENG) based on rice paper (RP) and Polydimethylsiloxane (PDMS) was fabricated for efficient energy harvesting. The device produced a high output of 305 V, 2.6 μA current, and a charge of 29 nC. Various biomechanical energies from different body motions were harvested using the RP-PDMS TENG device. Typically, the TENG output depleted under extreme environmental conditions. Hence, the TENG device was packed using a waste polythene pouch, which enabled greater stability of electrical voltage under harsh humidity conditions (>85 % RH). This packed TENG shows great promise for self-powered wearable devices and environmentally robust energy harvesting applications. 2026-02-28T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/58302 Title: A 0.05 mm3 diode-based single charged-particle real-time radiation detector for electron radiotherapy Author(s): Lee, Kyoungtae; Lall, Rahul; Maharbiz, Michel M.; Anwar, Mekhail Abstract: Real-time radiation monitoring at the single-particle level is an unmet need for electron radiotherapy, especially for dose deposition to targets in motion or critical OARs. We have developed a first-in-class CMOS-based 0.05 mm3 single electron sensitive detector. The chiplet integrates all the requisite electronics. The functionality of the system is verified under 6 and 9 MeV clinical electron beams. Percentage depth vs. pulse-width curves for 6 and 9 MeV beams are measured and verified using Monte-Carlo simulations. The proposed system has the potential to enhance the electron radiotherapy quality and safety, providing real-time dosimetry from multiple sites simultaneously. © 2025 The Author(s) 2025-03-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/58230 Title: Single-X-Ray Sensitive Energy-Binning Dosimeter for Closed-Loop Cancer External-Beam Radiotherapy Author(s): Lall, Rahul; Lee, Kyoungtae; Cunha, Adam; Abergel, Rebecca; Seo, Youngho; Niknejad, Ali M.; Anwar, Mekhail Abstract: X-ray radiation dose delivered during cancer external-beam radiotherapy (EBRT) is nonlinear with the biological effect imparted to cancer cells and neighboring healthy tissues. This oftentimes leads to insufficient damage to cancer cells and excessive damage to the surrounding healthy tissues, both increasing toxicity and the risk of cancer recurrence later in life for many patients. An understanding of X-ray energy deposition at the single-X-ray level is, therefore, necessary to improve the efficacy of cancer radiotherapy. Here, we present a single-X-ray sensitive, energy-binning integrated circuit (IC)-based dosimeter, fabricated in 180 nm CMOS technology, to enable closed-loop cancer radiotherapy for personalized patient treatment. We use small 3 x 3 mu m reverse-biased deep n-well (DNWELL) diodes designed at low capacitive nodes (C-diode), such that the miniscule charge deposition (Q(dep)) from single X-rays at these nodes generates a voltage signal large enough to be sensed (V-diode = Q(dep)/C-diode). In order to enable single-X-ray energy resolution without significant power and area, we implement an analog voltage supply (AVDDH) similar to log resistor grid to create a sensitivity gradient across the 76 x 55 pixel array. The IC-based dosimeter was tested under scenarios consistent with the treatment of shallow lesions (e.g., skin cancer, superficial tumors, intraoperative radiotherapy). The system is highly linear with radiation dose (10-250 cGy) and accurately tracks dose up to 2 cm deep in tissue for 50-, 70-, and 100-kV X-ray beams. 2025-03-31T15:00:00Z