A5087306538- Advanced Power Amplifier Design
- Advanced MIMO Systems Optimization
- Full-Duplex Wireless Communications
- Radio Frequency Integrated Circuit Design
- Advanced Optical Sensing Technologies
- Ocular and Laser Science Research
- Quantum Information and Cryptography
- CCD and CMOS Imaging Sensors
- VLSI and FPGA Design Techniques
- Clay minerals and soil interactions
- Antenna Design and Optimization
- Quantum Mechanics and Applications
- Quantum optics and atomic interactions
- Radiation Detection and Scintillator Technologies
- Manufacturing Process and Optimization
- Telecommunications and Broadcasting Technologies
- Cosmology and Gravitation Theories
- 3D IC and TSV technologies
- Energy Harvesting in Wireless Networks
- Soil and Unsaturated Flow
- Advanced DC-DC Converters
- Power Line Communications and Noise
- Electromagnetic Compatibility and Noise Suppression
- Landfill Environmental Impact Studies
- Space Satellite Systems and Control
University of Waterloo
2017-2024
Korea Atomic Energy Research Institute
2012
Models of quantum systems on curved space-times lack sufficient experimental verification. Some speculative theories suggest that properties, such as entanglement, may exhibit entirely different behavior to purely classical systems. By measuring this effect or thereof, we can test the hypotheses behind several models. For instance, predicted by Ralph and coworkers [T C Ralph, G J Milburn, T Downes, Phys. Rev. A, 79(2):22121, 2009, Pienaar, New Journal Physics, 16(8):85008, 2014], a bipartite...
Avalanche photodiodes (APDs) are a practical option for space-based quantum communications requiring single-photon detection. However, radiation damage to APDs significantly increases their dark count rates and thus reduces useful lifetimes in orbit. We show that high-power laser annealing of irradiated three different models (Excelitas C30902SH, Excelitas SLiK, Laser Components SAP500S2) heals the several restored typical pre-radiation rates. Of nine samples we test, six were thermally...
This article introduces an active calibration scheme tailored for fully digital multiple-input multiple-output (MIMO) transmitters, a key step toward ensuring channel reciprocity. The theoretical analysis starts by examining the influence of antenna mutual coupling and power amplifier (PA) output impedances on MIMO transmitter highlights significant impact inherently poor matching, exhibited in high-efficiency PAs, exacerbating effects Consequently, is formulated to concurrently characterize...
This paper presents the hardware implementation of a real-time digital predistorter (DPD) for fully multiple-input multiple-output (MIMO) transmitters. The is comprised dual-input single-output (DISO) DPD module each chain and shared crosstalk mismatch (CTMM) that estimates reflected wave back into PA. proposed DISO piece-wise linear (PWL) model implemented on field-programmable gate array (FPGA) achieves linearization bandwidth up to 1.2 GHz at clock rate 300 MHz. engine demonstrated...
Avalanche photodiodes (APDs) are well-suited for single-photon detection on quantum communication satellites as they a mature technology with high efficiency without requiring cryogenic cooling. They are, however, prone to significantly increased thermal noise caused by in-orbit radiation damage. Previous work demonstrated that one-time application of annealing reduces radiation-damage-induced APD noise. Here we examine the effect cyclical proton irradiation and annealing. We use an...
This article investigates the impact of precoding on performance massive multiple-input multiple-output (mMIMO) transmitters exhibiting nonnegligible antenna crosstalk. For this, a new metric, called average active impedance, is introduced to quantify extent load modulation as function S-parameters and employed precoding. The metric then used investigate under conventional schemes. It shown that these precoders yield large disparities in average-power levels across radio frequency (RF)...
Single-photon avalanche photodiodes (SPADs) based on silicon are widely considered for quantum satellite communications but suffer from an increasing dark count rate (DCR) due to displacement damage in their active areas induced by proton radiation. When the DCR of SPADs exceeds a certain threshold, they become unusable communication protocols. Previous laboratory experiments have demonstrated that laser annealing SPADs' area with about 1~W optical power can significantly reduce...
This letter lays the foundation for reducing required number of transmitter-observation receivers (TORs) training digital predistortion (DPD) in fully massive multiple-input, multiple-output (MIMO) transmitters. Specifically, it investigates viability applying same, common set DPD coefficients to linearize all RF chains MIMO First, is shown that if are operated at same output power, can be found by simply averaging obtained each chain on its own. suggests only a few may needed provided...
This paper proposes a comprehensive electromagnetic/radio-frequency/digital signal processing (EM/RF/DSP) co-simulation framework that enables predictive analysis of fully digital multiple-input multiple-output (MIMO) transmitters using modulated signals. It seamlessly integrates complementary EM, RF and DSP simulators to analyze the effects design choices at level circuits algorithms, their interactions. The usefuleness proposed is experimentally validated by evaluating its ability predict...
This paper presents an experimental study of the effects antenna crosstalk on linearizability and efficiency fifth-generation (5G) sub-6 GHz wideband massive multiple-input multiple-output (MIMO) transmitters. The transmitter consists 2 × arrays class AB Doherty power amplifiers (PAs) connected to array with reconfigurable spacing. ability single-input single-output (SISO) dual-input (DISO) digital predistortion (DPD) techniques linearize PA is assessed under 5G-candidate 100 MHz orthogonal...