Tidak Diketahui Pusat Pengajian - Tesis

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The Design Of High-Speed Cmos Pipelined Adc And Hybrid Dac For Wireless Communication
(2024-10)
Idros, Norhamizah
The increasing data rates required by cutting-edge wireless communication systems have intensified the demand for high-speed adcs and dacs. Therefore, this research presents an innovative 16-bit 400 ms/s pipelined adc and hybrid dac, designed using the 65 nm cmos process and a supply voltage of 1 v. In pipelined adcs, resolution and sampling rate are primarily constrained by open-loop dc gain and unity-gain frequency of operational amplifier (op-amp) as their core component. However, achieving high-performance op-amp comes at the cost of increased power consumption. Therefore, the proposed adc features an inventive dual gain boosting op-amp that surpasses a unity-gain frequency of 5 ghz and an open-loop dc gain of 100 db. The adc occupies an active area of 0.83 mm² and consumes 50 mw of power. The adc exhibits an sndr of 73.0 db, resulting in a schreier fom of 168 db. The high-speed systems also introduces glitches in dacs, which severely impair the linearity and overall dac performance. Glitch-reduction techniques enhance the performance of dacs, with the trade-off in power consumption. Hence, this research proposes a novel hybrid dac, incorporates a digital filtering mechanism designed to eliminate glitches. The dac combines a 6-msb current-steering and a 10-lsb binary-weighted resistor architectures, resulting a total power consumption of 8.36 mw within an active area of 0.06 mm².
Multistage Power Amplifier In 180nm CMOS Technology With Integrated Passive Linearizer For IEEE 802.15 Application
(2018-10)
Gunasegaran, Premmilaah
As wireless communication standard continues to evolve accommodating the demand of high data rate operation, the design of RF CMOS power amplifier (PA) becomes ever challenging. PAs are required to operate more efficiently while maintaining stringent linearity requirement. In this work, the low power linear multistage CMOS power amplifier for BLE application is designed and implemented.
High Linearity And High Efficiency Cmos Power Amplifier And Up-conversion Mixer For 5g New Radio Sub-6 Ghz
(2024-09)
Gunasegaran, Premmilaah
Fifth Generation (5G) New Radio (NR) is the latest wireless technology designed to meet the growing demands of modern networks and connected devices, but it imposes stringent requirements on transmitters, leading to potential reductions in efficiency due to high power usage. In this study, a highly efficient and linear CMOS power amplifier (PA) and up-conversion mixer were developed for 5G NR Sub-6GHz applications. A mixer-based linearizer was integrated at the PA's input to enhance performance across a wide frequency range, ensuring the system maintained high efficiency and linearity even with a 3 dB reduction in output power. The integrated CMOS PA and mixer, fabricated using 130 nm CMOS technology, cover a 1 GHz bandwidth from 4 GHz to 5 GHz. Measurement results demonstrated a gain of over 30 dB, with maximum output power ranging from 23.85 to 23.39 dBm, peak power-added efficiency (PAE) from 41.3% to 41.04%, and an output third-order intercept point (OIP3) between 31.38 and 32.53 dBm. The system's ability to maintain linearity was confirmed through testing with a 16 QAM signal, highlighting the innovation of the mixer-based linearizer integrated with the mixer before feeding into the PA.
Characterisation Of Pectate Lyase Pelq1 From Saccharobesus Litoralis
(2024-01)
Melissa Lian, Qianyue
The pelQ1 gene from the marine bacterium Saccharobesus litoralis CCB-QB4 encodes a pectate lyase that consists of two domains, which are polysaccharide lyase family 1 (PL1) and carbohydrate-binding module family 13 (CBM13). CBM13 which is involved in substrate binding is often found in pectate lyases (Pels) from marine sources but not terrestrial sources. Moreover, the study of marine Pels is lacking since pectin is not one of the major sources of carbohydrates in the marine environment. Therefore, this study aimed to elucidate the cleaving mechanism of PelQ1 by comparing the activity of the full-length enzyme (PelQ1-Full) and the truncated enzyme with CBM13 removed (PelQ1-PL1). Both enzymes were cloned, purified, characterized, and their cleaving mechanisms were elucidated. PelQ1-Full exolytically cleaved the substrate polygalacturonic acid (PGA) to produce a majority of unsaturated trigalacturonic acid; however, it cleaved the citrus pectin (CP) into a majority of unsaturated digalacturonic acid when high enzyme concentrations were used. PelQ1-Full worked in an optimal condition of pH 9.0, 30°C, and 0.6 mM CaCl2. Comparison between the two enzymes showed that there was a slightly higher catalytic efficiency (kcat/KM) towards PGA than CP, while TLC results showed that the CBM13 domain might help substrate binding. The AlphaFold homology model of the PL1 domain showed that it had a structure of parallel β-helix and a high sequence similarity with PelC of Dickeya dadantii. The CBM13 domain showed a structure of β-trefoil fold similar to other CBM13 domains.
Multiband Cmos Power Amplifierwith Integrated High-Q Compact Inductor For Lora Application
(2023-05)
Arvind Singh Rawat
In the wide development of the Internet of Things (IoT), Machine-to-Machine (M2M), and biomedical applications in research and standardization, the spectrum of sub-GHz has received fresh attention. Long-range (LoRa) devices use the sub-GHz frequency bands to operate. The size of the chip becomes bigger when designed to target low frequencies and it is mainly contributed by the inductors. In this research, a high-performance CMOS power amplifier (PA) with a novel custom shape, high Qfactor compact inductor (HQCI) is fabricated in 130 nm, 6-metal layers CMOS process.

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