Spoof Surface Plasmon Polaritons Developed from SIW Using Ring Slots and Vias

A new type of spoof surface plasmon polaritons (SSPPs) developed from conventional substrate integrated waveguide (SIW) using ring slots and vias is proposed in this paper. The asymptotic frequency and lower cutoff frequency of the SSPP structure can be easily tuned by changing the width of SIW walls and radius of the ring slot, respectively. A trapezoidal microstrip line and a small ring slot are used for the efficient mode conversion to smoothly transit from microstrip line to the proposed SSPP structure. The presented SSPPs have a flat bandpass filtering response with adjustable center frequency and bandwidth. In order to better verify the transmission and cutoff characteristics, two bandpass filters using the proposed SSPPs with relative bandwidths of 61.7% and 76.4%, respectively, are fabricated and measured. Good agreement between the simulations and measurements verifies the proposed design idea.

FUNCTIONAL ASSIGNMENT OF TECHNOLOGICAL ACCESSORIESFOR WOODWORKING

Urgency of the research. The use of modern technological accessories allows increasing the productivity of woodworking pro-cesses, the accuracy and quality of wood products and furniture. Also, technological accessories allows to expand the technological capabilities of woodworking accessories, tools, to ensure safe working conditions during mechanical processing of wood.Target setting. When designing technological processes for woodworking and furniture production, the task of choosing or designing technological accessories always exists. For a reasonable choice or design of technological accessories in the woodworking industry, an analysis of the functional purpose is important.Actual scientific researches and issues analysisis devoted to works on the functional analysis of technical systems and the choice of technological accessories.Uninvestigated parts of general matters defining. At the moment, little attention has been paid to the issues of selection and design of technological accessories for woodworking and furniture production in the scientific literature. Analysis and systemati-zation of the functions of technological accessories for woodworking will allow for a more informed choice and design.The purpose of the articleis to determine the functions of technological accessories for woodworking and furniture pro-duction for a more informed choice and design.The statement of basic materials. based on the principles and approaches of the functional analysis of technical systems, the method of formulating the functional assignment of technological equipment for woodworking and furniture production is presented in the work. the main and auxiliary functions are formulated as an example of a conductor with an adjustable center distance. an example of the formulation of the functional assignment of a device for mechanical processing of a wooden blank is given.Conclusions. In this work, for the first time, a general approach to the functional analysis of technological accessories for woodworking is proposed. The functions of the technological accessories are determined and their applied application is demonstrated. The presented materials can be used for an informed choice or design of technological equipment for wood-working and furniture production.

A bandpass sigma-delta modulator with the function of adjustable center-frequency

A bandpass sigma-delta modulator with the function of adjustable center-frequency is present in this paper. A method used to convert 2-order low-pass modulator to 4-order bandpass modulator is proposed to realize the design. Center-frequency that can be set to 1/6, 1/4 and 1/3 of sampling frequency is controlled according to the digital logic voltage. The bandwidth of pass-band is 200 Hz. Test results show that the average SNR is about 80 dB at different center-frequency when the sampling frequency is 64 kHz. The input signal can reach to −3 dBFs. The complexity to design a variable center-frequency bandpass modulator is greatly reduced.

A Real-time QRS Detector Based on Low-pass Differentiator and Hilbert Transform

Electrocardiogram(ECG) is an important physiological signal of the human body. It is widely used in identification and arrhythmia detection. The first step of ECG application is signal segmentation, that is, the QRS detection. An effective and real-time QRS detection algorithm is proposed in this paper. A differentiator with adjustable center frequency is used to capture the first derivative information of the frequency band of the electrocardiogram. Then Hilbert transform is used to generate the envelope of the first derivative. After that, a dual threshold method is introduced to decrease FP and FN. Finally, a more precise R wave position is determined based on derivative method. The detector is validated on MIT-BIH arrhythmia database. The result show that the proposed algorithm has a high Sensitivity of 99.87%, Specificity of 99.84%, and the detection error rate is 0.28%. The average execution time of a 30 minutes record is 2.45s.

K-band MEMS-based frequency adjustable waveguide filters for mobile back-hauling

This paper presents the first experimental results of a novel MEMS-based waveguide filter for mobile back-hauling at K-band with adjustable center frequency. The tuning concept employs commercial packaged RF MEMS switches, wire-bonded within a rectangular cavity. The switches are used to perturb the current distribution of the TE101 mode so as to tune the resonant frequency of the cavity. A tuning range up to 2% with unloaded Qs of the order of 1000 in K-band can be obtained. A second-order filter prototype employing commercially available MEMS on silicon substrate has been tested. Measurements show a 160 MHz frequency shift (0.7%) and Qs up to 1000 using only one MEMS per resonator. New higher-order prototypes using low-loss substrate MEMS (e.g. quartz) will be fabricated in order to get higher Qs. The concept here present leads to a very simple structure. The number of MEMS per resonator is, in fact, minimized (we use only one MEMS) and the design is simple. On the other hand, the achievable tuning range is lower (<2%) than the other concepts. Higher tuning ranges are achievable using more MEMS, but at the expense of lower Qs of the resonators.