Wireless Connectivity

Overview

Wireless communications are inevitable in modern societies, catering to diverse application requirements such as high-speed, wide-bandwidth links, low-latency communications, and high-reliability security applications. At the same time, minimizing power consumption is essential for ensuring the long-term scalability of wireless communication technologies.

Our group is committed to advancing wireless communications through innovative circuit and system design, experimental validation, and interdisciplinary collaboration. Our work spans multiple levels, including key circuit components, subsystems, system architectures, and advanced packaging techniques.

Key research directions

  1. Key Components and Subsystems (mm-Wave and THz):
    • Power Amplifiers (PAs): Development of efficient, wideband power amplifiers to enhance signal strength and transmission distance in high-frequency millimeter-wave communications.
    • Low-Noise Amplifiers (LNAs): Design of low-noise, high-gain amplifiers to ensure superior signal reception while minimizing interference.
    • Variable Gain Amplifiers (VGAs): Creation of adjustable gain amplifiers to optimize signal strength and system sensitivity under varying operational conditions.
    • Phase Shifters: Investigation of high-precision phase shifters for accurate beam steering, improving beamforming capabilities.
    • Synthesizers: Development of mm-wave synthesizers with minimized power consumption and phase noise.
  2. Multiple Antenna Systems:
    • Phased-Array and MIMO Systems: Enhancing spectral efficiency, dynamic range, and interference robustness for adaptive wireless communications in complex environments.
    • Reconfigurable and Intelligent Wireless Systems: Implementation of tunable and AI-driven wireless front-end solutions to improve adaptability and performance.
    • Wide-Bandwidth Support & Beam Squinting Minimization: Ensuring high-frequency systems maintain performance across wide bandwidths with an enhanced field of view.
    • Antenna Coupling Mitigation: Minimizing grating lobes to enhance signal radiation efficiency while addressing undesired antenna coupling.
    • Effective Synchronization Across Large Arrays: Developing methodologies for precise system synchronization across large-scale antenna arrays.

This research direction is a collaborative effort within our group, with contributions from experts in RF systems, antenna technologies, and communication engineering. Our collective goal is to push the boundaries of high-frequency communication systems, improving performance for applications in future wireless technologies.

Publications

  1. H. Gao et al., “A Ka-band 8-Element 4-Beam Transmitter Front End With Hybrid VGA and Symmetrical Transformer-based Doherty PA,” 2024 IEEE Radio Frequency Integrated Circuits Symposium (RFIC), Washington, DC, USA, 2024, pp. 7-10.
  2. H. Gao et al., “A K -Band Four-Beam Transmitter With Decoupled Phase/Gain Control and Enhanced Power Back Off Efficiency for SATCOM,” in IEEE Transactions on Microwave Theory and Techniques, vol. 72, no. 11, pp. 6443-6459, Nov. 2024.
  3. H. Gao et al., “A 6.5–12-GHz Balanced Variable-Gain Low-Noise Amplifier With Frequency-Selective Gain Equalization Technique,” in IEEE Transactions on Microwave Theory and Techniques, vol. 69, no. 1, pp. 732-744, Jan. 2021.
  4. H. Gao et al., “A 6.5-12 GHz Balanced Variable Gain Low-Noise Amplifier with Frequency-Selective Non-Foster Gain Equalization Technique,” 2020 IEEE/MTT-S International Microwave Symposium (IMS), Los Angeles, CA, USA, 2020, pp. 321-324.