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For the first time, a MgAl2O4 transparent ceramic cylindrical dielectric resonator antenna (DRA) is designed using the fundamental HE11δ modes for slot excitation. The transparent microwave dielectric ceramic was synthesized using high-purity MgO and γ-Al2O3 powders by aqueous gel-casting combined with cold isostatic pressing, pressure-less sintering and hot isostatic pressing methods. Optimum relative permittivity ∼8.2, Q × f (Q = quality factor = 1/dielectric loss, f = resonant frequency) ∼110 510 GHz and temperature coefficient of resonant frequency ∼−74.1 ppm °C−1 were obtained. The reflection coefficient, the input impedance, the antenna gain and the radiation pattern of the transparent cylindrical ceramic DRA were examined, and it was observed that the simulation results were in reasonable agreement with the measurement results. It has been found that the proposed transparent cylindrical MgAl2O4 ceramic DRA can provide a higher impedance bandwidth (BW = 735 MHz) and radiation efficiency (95.8%) than a state-of-the-art transparent glass DRA. The proposed configuration can potentially be used for such useful antenna decoration and can be used as a lampshade to integrate these antennas in street and traffic lights without compromising the aesthetics of the city.

Transparent material has been widely used in product design and has seen a large increase in its use. In this paper, a kind of aesthetically decorative 5 GHz Wi-Fi dielectric resonator antenna (DRA) of aluminum oxynitride (AlON) transparent ceramic has been designed. High-quality-factor AlON transparent dielectric ceramics were fabricated by presintering at 1780 °C and further cold isostatic pressing (CIP) under a 200 MPa argon atmosphere. For a 9.0 mm thick specimen, the in-line light transmittance reached 83%. Optimum dielectric constant (er = 9.32), quality factor (Qf = 47 960) and temperature coefficient (TCF = -51.7 ppm/°C) was achieved in the AlON transparent ceramic by cold isostatic pressing. As a result, the proposed aesthetically decorative DRA can achieve an impedance bandwidth of 32% (4.48-6.19 GHz), a high radiation efficiency of 85%, and a low cross-polarization discrimination (XPD) of -30 dB. To achieve a broad bandwidth, the proposed antenna was excited in its dominant TE111x mode and higher-order TE113x mode. The proposed antenna is thus an excellent candidate for an indoor decoration Wi-Fi antenna.

The purpose of this paper is the development of flame retardant chef coats fabric. The main properties of polysulfonamide fiber are described , the research and development of the product processing of polysulfonamide /Aramid 1313 blended yarn and the union fabric with it and cotton yarn are explored. The technology problems of spinning and weaving are solved. The mechanical property , comfort property and flame retardance of the fabric of polysulfonamide /Aramid 1313 blended yarn and cotton yarn are qualified .The product can be used for high grade chef coats fabric.

In this article, a novel band-notched ultra-wideband (UWB) bandpass fllter based on hybrid microstrip/slotline structure is proposed. A quad-mode stubs-loaded slotline resonator is fed by two orthogonal microstrip lines and ultra-wideband bandpass characteristic is excited. A stub-loaded dual- mode microstrip resonator is externally loaded to the quad-mode slotline resonator, and a notched band with sharp roll-ofi characteristic is achieved. The circuit model for the dual-mode microstrip resonator loaded slotline is given and analyzed. The proposed fllter is designed and fabricated. Simulated and measured return losses are i12dB/i18dB and i18dB/i10dB in lower and higher passband. The return loss in the notched band is greater than 15dB.

3D woven fabric significantly improves the mechanical properties, especially the strength resulting from the between layers connections of yarns Hence, 3D woven fabrics have been widely used as reinforcing material in prefabricated composites, A particular 3D woven fabric with “中” shaped cross section was developed in this study .The fabric was made in a plane loom weaving machine. The designing procedure and processing methods are given in details.

With the development of modern technology, fiberglass composite materials are widely applied. The advantages of fiberglass reinforced composite materials are high strength and light weight. In order to produce a prefabricated fiberglass composite, a machine chart was drafted for weaving the 3D fiberglass fabric with five layers. The obtained five-layer 3D fabrics were composited with polyurethane matrix. Afterwards, the performance of the prefabricated composites was tested and the optimal ratio of fiberglass to matrix was determined by statistical analysis.

A novel dual-mode bandpass fllter (BPF) using stub- loaded defected ground open-loop resonator is proposed in this article. Defected arrow-shaped stub is loaded to a defected ground open- loop resonator, and two non-degenerate modes are excited for dual- mode characteristics. Based on even- and odd-mode theory, dual- mode characteristics of the resonator is analyzed. Design equations for the defected-ground resonator are investigated. A two-pole dual- mode bandpass fllter operating at 2.4GHz with fractional bandwidth of 7.97% is designed, fabricated, and measured. Good agreement between simulated and measured results verifles the validity of this design methodology.

An improved spurline structure with two rejection bands is presented in this paper, which consists of asymmetrical spurline resonators and embedded directly into microstrip line. Asymmetrical spurline resonators provide dual-bandgap characteristics and slow-wave effect. Furthermore, asymmetrical spurline structure with dual rejection bands is proposed to reduce the higher harmonics of microwave power amplifiers. To evaluate the effect of asymmetrical spurline resonators on microwave amplifiers, two InGaP HBT power amplifiers were designed and fabricated. One of them has asymmetrical spurline structure at the output section, while the other has a conventional 50-Omega microstrip line only. Results show that asymmetrical spurline structure suppresses the second and third harmonics more than 27 dB at the output and yields improved power added efficiency (PAE) and output power by 6-8% and 1-4%, respectively.