- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Design of a Low-Cost Microstrip Directional Coupler with High Coupling for a Motion Detection Sensor
摘要： A coupled-line coupler based on the asymmetric cascade connection of two coupled line sections is used to achieve a high coupling factor using low-cost material and technology in the X frequency band, and its performance is compared with a standard quarter-wave, coupled-line coupler, showing an increase in the coupling factor of about 3 dB. The proposed coupler can be effectively used in a Doppler motion detection sensor, due to its strong coupling and relatively high isolation. The coupler is designed through a simple, yet rigorous, equivalent circuital model. Then, an optimization procedure was performed using the commercial software Ansys HFSS in order to compensate for losses and second order effects. A prototype of the designed coupler was realized, and the measured data show very good agreement with simulations.
关键词： coupled lines,directional coupler,motion detection systems
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE 15th International Conference on Group IV Photonics (GFP) - Cancun (2018.8.29-2018.8.31)] 2018 IEEE 15th International Conference on Group IV Photonics (GFP) - Optimization of a Polarization Beam Splitter for Broadband Operation using a Genetic Algorithm
摘要： We present a design method for a polarization beam splitter for broadband operation based on a genetic algorithm (GA). The devices are segmented into short sections, where the geometric parameters for each device are determined using a GA.
关键词： genetic algorithm,silicon photonics,directional coupler,broadband,optimization,beam splitter
更新于2025-09-23 15:22:29
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Broadband Mode Multiplexer Formed with Non-planar Tapered Directional Couplers
摘要： We propose a broadband mode multiplexer based on the structure of cascaded planar and non-planar tapered directional couplers (DCs), which are designed for processing vertically symmetric and anti-symmetric modes. The DCs are tapered to widen the operating bandwidth, reduce the polarization dependence, and improve the fabrication tolerance. As an example, we design and fabricate a five-mode (de)multiplexer with polymer material to combine or separate the E11, E12, E21, E31, and E22 modes. Our typical fabricated device has a length of 2.1 cm and shows the mode coupling efficiency of almost larger than 94.5% for each DC over the C + L band with weak polarization dependence. The proposed structure is scalable and can be implemented with different material platforms.
关键词： mode multiplexer,Mode-division multiplexing,tapered waveguide,directional coupler,polymer waveguide
更新于2025-09-23 15:22:29
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Design of silicon waveguide polarization beam splitter based on reversed ?? <i>?2</i> directional coupler
摘要： We report a directional coupler type polarization beam splitter using silicon waveguides designed for 1550–1600 nm wavelengths. The device uses the coupling strength difference between the TE and TM modes. We use a reversed Δβ structure to achieve a wide operational wavelength range. The gap between the waveguides needs to be wide enough to attain a sufficient extinction ratio for the TE mode. Simulation results show that an over 100 nm operational 20 dB extinction ratio wavelength range can be attained at 1520–1620 nm wavelengths by this simple structure. The fabrication width tolerance exceeds 10 nm which is enough for foundry processes.
关键词： polarization beam splitter,silicon waveguide,directional coupler,TE and TM modes,reversed Δβ structure
更新于2025-09-23 15:21:01
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Mechanoa??Photonics: Flexible Singlea??Crystal Organic Waveguides and Circuits
摘要： Microfabrication of circuits by combining the mechanical and photonic properties of flexible crystals is imperative for flexible miniature photonic devices. The fundamental understanding of molecular packing and energetics of intermolecular interactions is vital to design crystals with intrinsic flexibility and optical attributes. We present a unique one-dimensional optical waveguiding crystal of dithieno[3,2-a:2′,3′-c]phenazine (1) with high aspect ratio displaying high mechanical flexibility and selective self-absorbance of the blue part of its fluorescence (FL). Though, macrocrystals exhibit elasticity, microcrystals deposited at a glass surface behave incredibly like plastic crystals due to significant surface adherence energy, making them suitable for constructing photonic circuits via micromechanical operation with atomic force microscopy cantilever tip. Phenomenally, the flexible crystalline waveguides display optical path-dependent FL signals at the output termini in both straight and bend configuration suitable for wavelength division multiplexing technologies. A futuristic reconfigurable directional coupler fabricated via micromanipulation by combining two arc-shaped crystals split the optical signal via evanescent coupling and deliver the signals at two output terminals with different split ratios. The presented mechanical micromanipulation technique could also be effectively extended to any flexible crystals to design and carve complex photonic circuits.
关键词： Organic Photonics,Flexible Crystals,Directional Coupler,Optical waveguides,Mechano-photonics
更新于2025-09-23 15:21:01
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Wave Propagation in Randomly Perturbed Weakly Coupled Waveguides
摘要： We present an analysis of wave propagation in a two step-index, parallel waveguide system. The goal is to quantify the effect of scattering at randomly perturbed interfaces between the guiding layers of high index of refraction and the host medium. The analysis is based on the expansion of the solution of the wave equation in a complete set of guided, radiation, and evanescent modes with amplitudes that are random fields, due to scattering. We obtain a detailed characterization of these amplitudes and thus quantify the transfer of power between the two waveguides in terms of their separation distance. The results show that, no matter how small the fluctuations of the interfaces are, they have a significant effect at a sufficiently large distance of propagation, which manifests in two ways: The first effect is well known and consists of power leakage from the guided modes to the radiation ones. The second effect consists of blurring of the periodic transfer of power between the waveguides and the eventual equipartition of power. Its quantification is the main practical result of the paper.
关键词： equipartition of power,random waveguides,power leakage,directional coupler
更新于2025-09-23 15:21:01
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A Wideband On-Chip Directional Coupler Using a Negative Capacitance Circuit
摘要： We propose a wideband lumped element directional coupler using lossy negative capacitance (NCAP). NCAP provides a broadband resonance effect combined with passive inductors and capacitors in a circuit, enabling the coupler to exhibit wideband directivity performance. In addition, a 3-dB loss in the NCAP enhanced the bandwidth at the expense of the transmission gain, which decreased by only 0.3 dB. The proposed coupler was implemented in the IBM 7RF 180-nm CMOS technology. The size of the core chip is 1180 μm × 570 μm. The designed NCAP provides a capacitance of ?13 pF using a supply voltage of 2.7 V and a current of 9.6 mA. The coupling was designed to be ?10 dB at the center frequency of 1 GHz. The bandwidth was de?ned by the frequency range, which exhibited a directivity of more than 30 dB. The S-parameter measurements showed an absolute bandwidth ranging from 0.86 to 1.12 GHz, and a fractional bandwidth of 26%. In the bandwidth, the coupling had a 0.5-dB variation, the transmission loss was smaller than 2.14 dB, and the noise ?gures were 1.8–2.5 dB.
关键词： Broadband resonance,wideband lumped element (LE) directional coupler,negative capacitance (NCAP)
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 16th International Conference on Group IV Photonics (GFP) - Singapore, Singapore (2019.8.28-2019.8.30)] 2019 IEEE 16th International Conference on Group IV Photonics (GFP) - Compact Polarization Beam Splitter Based on a 3-Waveguide Directional Coupler with Broad Bandwidth Performance
摘要： Compact polarization beam splitter based on a 3-waveguide directional coupler with broad bandwidth performance
关键词： slot waveguide,directional coupler,Polarization beam splitter
更新于2025-09-23 15:19:57
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MINIATURIZATION OF TRANS-DIRECTIONAL COUPLED LINE COUPLERS USING SERIES INDUCTORS
摘要： A miniaturized trans-directional (TRD) coupled line coupler comprises series inductors and capacitor loaded coupled lines is proposed in the paper. Series inductors are added to the periodically loaded coupled lines for further miniaturization of volume. A novel equivalent circuit is presented and theoretically analyzed. Test circuits for the miniaturized and conventional 3-dB TRD couplers were designed to operate at 1.6 GHz and fabricated using printed circuit board (PCB) technology. Samples have been measured, and comparisons in terms of volume, schematic simulation results and measurement results between the miniaturized and conventional 3-dB TRD couplers have been made to validate the proposed structure. Results show that the proposed miniaturized TRD coupler achieves a size reduction of 47.6% compared to the conventional TRD coupler with similar performances.
关键词： PCB technology,trans-directional coupler,miniaturization,series inductors,coupled lines
更新于2025-09-23 15:19:57
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Broadband polarization-independent directional coupler using asymmetric-waveguides
摘要： A high-performance broadband polarization-independent directional coupler is designed by using asymmetric-waveguides con?guration on a silicon-on-insulator platform. Through the design of cascaded directional couplers, the coupling characteristics of the light with the orthogonally polarized transverse electric (TE) and transverse magnetic (TM) can be manipulated, so that the coupling strength could be equivalent between TE and TM polarizations within an ultra-broadband. Couplers with 50% splitting ratio are designed and simulated for operating in the wavelength range from 1450 nm to 1650 nm for both polarizations. Within the 100 nm wavelength range from 1500 nm to 1600 nm, the deviations of splitting ratio for TE polarization and TM polarization are ± 3.3% and ± 6.2%, respectively. And within the 200 nm wavelength range from 1450 nm to 1650 nm, the deviations for TE polarization and TM polarization are ± 9.0% and ± 7.8%, respectively. The footprint of this polarization-independent directional coupler is only 21 μm × 1.6 μm.
关键词： asymmetric waveguide,directional coupler (DC),Polarization
更新于2025-09-16 10:30:52