Action and identification problems are the challenges that visually impaired people often encounter in their lives. The high price of existing commercial intelligent auxiliary equipment has placed enormous economic pressure on most visually impaired people in developing countries. In order to solve this problem, this paper proposes a smart wearable system that performs image recognition. The system adopts the method of cloud and local cooperative processing. The cloud server mainly performs image processing, while the local unit only uploads images and feedback results. Therefore, the processor of the system does not need to use expensive high-performance hardware, and the cost is greatly reduced. Moreover, the algorithm running on the cloud server can also guarantee the speed and accuracy of recognition. In addition, we have changed the traditional video continuous scanning strategy to a mechanism for capturing points of interest, reducing power consumption. The attitude correction mechanism based on error codes of the system can effectively help the visually impaired to cope with the common living scenes, and the multiple priority feedbacks and arbitration mechanism will ensure real-time feedback of the system. The proposed smart wearable device has been tested in the actual scene, which proves to be helpful to the visually impaired people. It helps them find the right people and objects and read text.

Although tremendous efforts have been devoted to investigating planar single-conductor circuits, it remains challenging to provide tight confinement of electromagnetic field and compatibility with active semi-conductor components such as amplifier, harmonic generator and mixers. Single-conductor spoof surface plasmon polariton (SSPP) structure, which is one of the most promising planar single-conductor transmission media due to the outstanding field confinement, still suffers from the difficulty in integrating with the active semi-conductor components. In this paper, a new kind of odd-modemetachannel (OMM) that can support odd-mode SSPPs is proposed to perform as the fundamental transmission channel of the single-conductor systems. By introducing zigzag decoration, the OMM can strengthen the field confinement and broaden the bandwidth of odd-mode SSPPs simultaneously. More importantly, the active semi-conductor amplifier chip integration is achieved by utilizing the intrinsic potential difference on OMM, which breaks the major obstacle in implementing the single-conductor systems. As an instance, an amplifier is successfully integrated on the single-conductor OMM, which can realize both loss compensation and signal amplification. Meanwhile, the merits of OMM including crosstalk suppression, low radar cross section (RCS), and flexibility are comprehensively demonstrated. Hence, the proposed OMM and its capability to integrate with the active semi-conductor components may provide a new avenue to future single-conductor conformal systems and smart skins.

On-chip transmission lines (TLs) for spoof surface plasmon polariton (SSPPs) have been proved to suppress on-chip channel crosstalk in terahertz band due to their field confinement property. But the contradiction between strong field confinement and miniaturization limits the application of the on-chip SSPP TLs in millimeter and terahertz bands. Here, an ultra-compact on-chip SSPP TL with strong field confinement is proposed using 0.18 μm CMOS technology. The proposed SSPP TL reduces the cutoff frequency down to 435 GHz in a very limited TL width. Broadband feeding without using gradient transition structures is presented to guarantee the compact size. Compared to microstrip and the typical SSPP TLs, outstanding field confinement of the novel on-chip SSPP TL is demonstrated by the electrical-field- intensity distributions. Measured result matches to simulated one well. It is shown that the proposed on-chip SSPP TL possesses the lowest cutoff frequency and the smallest width relative to the cutoff wavelength, compared to the microstrip and the typical SSPP TLs. Thus the ultra-compact on-chip SSPP TL with strong field confinement may be widely used in the future miniaturized monolithic microwave integrated circuits (MMICs).

The dual band filtering characteristics of a spoof surface plasmonic waveguide loaded with a composite slot structure are studied in the present paper. The proposed composite slot structure enables the plasmonic waveguide to work at dual bands in the microwave region, where the working bandwidth can be flexibly adjusted with a broad isolation band between them. In particular, the second bandwidth can be adjusted independently without affecting the first passband by controlling the special parameter of the composite slot. As a demonstration, the measurement results of the proposed prototype filter illustrate that the plasmonic filtering waveguide has a dual bandpass performance with excellent frequency selectivity, where the insertion loss of the dual-band filter is less than -3 dB in the frequency from 2.7 GHz to 6.7 GHz and 7.7 GHz to 9.1 GHz, and the stopband rejection level is lower than - 10 dB from 6.9 GHz to 7.5 GHz. Compared with the traditional dual band plasmonic filtering waveguide, the proposed filter has compact physical size, lower insertion loss in the passband and stronger isolation ability between the two passbands.

Photonic integrated circuits (PICs) and microwave integrated circuits (MICs) have been widely studied, but both of them face the challenge of miniaturization. On one hand, the construction of photonic elements requires spaces proportional to wavelength, and on the other hand, electromagnetic compatibility issues make it challenging to reach high-density layouts for MICs. In this paper, we review the research advances of miniaturized PICs and MICs based on surface plasmon polaritons (SPPs). By introducing SPPs, miniaturized photonic elements at subwavelength scales are realized on PICs, which can be used for highly integrated interconnects, biosensors, and visible light wireless communications. For MICs, since the metals behave as perfect conductors rather than plasmonic materials at microwave frequencies, plasmonic metamaterials are proposed to support spoof SPPs. Spoof SPPs possess similar characteristics to SPPs and can be used to realize high-density channels on MICs. Moreover, combining the latest theoretical research on SPPs, future tendencies of SPP-based MICs are discussed as well, including further miniaturization, digitization, and systematization.