Robust object detection in autonomous driving is challenged by inherent limitations of conventional frame-based cameras, such as motion blur and limited dynamic range. In contrast, event-based cameras, which operate asynchronously and capture rapid changes with high temporal resolution and expansive dynamic range, offer a promising augmentation. While the previous research on event-based object detection has predominantly focused on algorithmic enhancements via advanced preprocessing and network optimizations to improve detection accuracy, the practical engineering and integration challenges of deploying these sensors in real-world systems remain underexplored. To address this gap, our study investigates the integration of event-based cameras as a complementary sensor modality in autonomous driving. We adapted a conventional frame-based detection model (YOLOv8) for event-based inputs by training it on the GEN1 dataset, achieving a mean average precision (mAP) of 70.1%, a significant improvement over previous benchmarks. Additionally, we developed a real-time object detection pipeline optimized for event-based data, integrating it into the CARLA simulation environment and ROS for system prototyping. The model was further refined using transfer learning to better adapt to simulation conditions, and the complete pipeline was validated across diverse simulated scenarios to address practical challenges. These results underscore the feasibility of incorporating event cameras into existing perception systems, paving the way for their broader deployment in autonomous vehicle applications.
This research proposes a quad-mode H-beam metasurface (MTS)-embedded dual-band circularly-polarized (CP) multi-tiered antenna scheme with 5G (n79) and Wi-Fi 6E capabilities. The proposed antenna scheme consists of three layers of corner-truncated FR-4 substrates without an air gap. The upper substrate contains an array of $3\times 4$ H-beam MTS elemental units tilted at 49°. The middle substrate is a copper plate with a horizontal Z-shaped slot at its center functioning as the ground plane, and the lower substrate contains a microstrip feed line. Characteristic mode analysis (CMA) is employed to optimize the circular polarization of the MTS structure. Results show that Modes 1 & 2 at 4.81 GHz and Modes 4 & 9 at 6.2 GHz contribute to CP radiation. The measured return loss bandwidths of the antenna are 19.37% (4.63 – 5.56 GHz) and 9.51% (5.97 – 6.56 GHz) for the 5G (n79) and Wi-Fi 6E bands. The measured axial ratio bandwidths are 13.33% (4.6 – 5.24 GHz) and 1.77% (6.15 – 6.26 GHz), with maximum gains of 5.2 and 3.9 dBic at 5.5 and 6.2 GHz, respectively. Unlike conventional MTS-based CP antennas which employ rectangular- or square-shaped MTS elements for single-band operation, this work utilizes H-beam-shaped MTS elemental units to achieve dual-band CP capability. Additionally, rather than traditional full-wave methods, CMA is used to optimize circular polarization. Essentially, the proposed antenna scheme is suitable for 5G (n79) and Wi-Fi 6E communications.
This paper proposes a dual-mode wide-band bandpass filter using the microstrip loop resonators with tuning stubs. The filter is based on microstrip loop resonator consists of four identical branches and each branch is a microstrip open-loop element. The introduction of two outer tuning stubs connecting opposite to the ports widens the passband and sharpens the stopbands. The microstip loop resonator have a wide stopband resulting from the dispersion effect and the slow-wave effect. The filter is designed at center frequency of 2.35 GHz and simulated by IE3D. The measurement of fabricated structure proposes 36% bandwidth and 0.28 dB insertion loss.
7 March 2018 in IET Microwaves, Antennas & Propagation
A four‐port diplexer consisting of two back‐to‐back three‐port diplexers combined with a 180° phase shifter in one branch is presented. The technique achieves high Tx/Rx isolation with relatively low degree filters. Two experimental diplexers are demonstrated, one with equal Q resonators in all filters and the other with dissimilar Q factors, enabling miniaturisation and cost reduction. Measured results of Tx/Rx diplexer devices at 2.13/1.73 GHz are presented and 40 dB Tx/Rx isolation is achieved with only second‐order filters.
Wireless communication technology evolves to meet current needs, focusing on antenna size reduction for smaller, multi-frequency devices. This research introduces a novel approach to miniaturizing a multiband Electromagnetic Band Gap (EBG) reflector using a Double Interdigitated Coplanar Waveguide (DICPW) structure. The mushroom-patterned EBG unit cell, employing a double interdigital technique based on a Coplanar Waveguide (CPW), achieves a significantly slower wave on the transmission line. The unit cell size can be reduced from λ/2 to λ/8, allowing control over the second to fourth resonance frequencies. Engineered for a fundamental frequency of 1.8 GHz (LTE), the proposed EBG unit cell supports frequency ranges of 2.45 GHz (WLAN), 4.3 GHz (Altimeter), and 5.2 GHz (WLAN). Integrating this EBG reflector with a dipole antenna at the same frequency results in directional radiation patterns and gains of 8.29 dBi, 8.76 dBi, 8.55 dBi, and 8.22 dBi at resonance frequencies. The innovative reflector, with improved gain and compact dimensions, is relevant to cube satellite and wireless communication systems with versatile multiband frequency requirements.
5 June 2025 in Engineering Science and Technology, an International Journal