Energy Risks Zoning and Demand Forecasting in Jiangsu rovince

AbstractThis paper takes Jiangsu province as an example, divides the zone of energy risks and uses GM (1, 1) and the combination of BP network model to forecast energy demand in this region.Finally, we adopt ARCEngine secondary development achieving the system simulation, and putting forward a strategic suggestion on energy problem of Jiangsu province. The study provides the scientific data support for making energy policy rationally, reducing the increasingly prominent phenomenon of energy demand and offer support for different levels in different departments.It can provide the scientific basis for risk prevention and comprehensive risk management plan.© 2011 Published by Elsevier Ltd. Selection and peer-review under responsibility of RIUD

Thin Transmitarray Panel with full 360-degree Phase Shift Range

This paper presents a new design technique to reduce the thickness of the transmitarray (TA) panel while maintaining 360 o phase shift range. Two types of unit cells, the receive-transmit unit cell and the frequency selective surface (FSS) unit cell, are placed in the same aperture. Comparing to the existing ultra-thin TA designs of similar panel thickness, the presented TAs do not suffer from the phase quantization loss and achieve better aperture efficiency. This study proves that it is viable to mix different types of TA unit cells to design a TA. The developed TA shows better gain than a homogeneous TA using the same elements and improved the overall efficiency by 60%. To verify the design concept, one TA with central frequency at 13.3 GHz was designed, fabricated and measured. The measured gain is 21.3 dBi and the calculated aperture efficiency of the TA is 37.9%

Millimetre-Wave Dual-Polarized Differentially-Fed 2D Multibeam Patch Antenna Array

In this paper, a novel millimetre-wave dual-polarized 2D multibeam antenna array incorporating differentially-fed antenna elements is proposed to achieve high cross-polarization discrimination (XPD) when the beams scan to the maximal pointing angles. The antenna element is composed of a SIW cavity with four shorted patches placed inside, and it is differentially excited for dual-polarization by a pair of feeding strips and transverse slots beneath the patches. Differential excitation is realized by a power divider designed on two laminate layers. Two Butler Matrices placed perpendicularly with each other in different laminates are employed to generate four tilted beams with dual-polarization. A 2 × 2 dual-polarized 2D multibeam antenna array working at 28 GHz is designed, fabricated, and measured. The operation bandwidth of the antenna is 26.8 GHz – 29.2 GHz. The improvement in the XPD is experimentally demonstrated by far-field measurement. When the beams scan to 30◦ off the boresight, the measured XPDs are 28 dB at the centre frequency and higher than 25 dB over the operation bandwidth, which confirms that the cross-polarized radiation in the 2D multibeam antenna array is suppressed by using the differential-feeding technique. The measured gain is in the range from 7.6 dBi to 10.5 dBi

Low-Cost Smart Antenna Using Active Frequency Selective Surfaces

Smart antenna is a key technology for advanced wireless systems and one of the most important features of smart antenna is electronically beam scanning or switching. It is highly desirable to reduce the mass, power consumption and cost of smart antennas, as the traditional phased array is always associated with high cost due to the use of many T/R modules and complicated beamforming network (BFN). This paper presents the University of Kent's recent research progress in the field of low-cost smart antenna design using active frequency selective surfaces (AFSS). Firstly, this paper presents a brief review of AFSS based beam-reconfigurable antenna including several recent designs reported by the authors' group. Then, a new high-gain AFSS antenna design with some preliminary results will be presented. This is design achieves higher gain than the reported AFSS antennas. A detailed list of references is given at the end of this paper

A Dual-Polarized Planar Antenna Array Differentially-Fed by Orthomode Transducer

This paper presents a new design of a differentially-fed substrate integrated planar antenna array with dual-polarization. Compared with the traditional dual-polarized antenna arrays, the proposed array antenna has the advantages of simple configuration, high cross-polarization discrimination (XPD) and high gain. 2×2-element subarray design with a vialoaded crossover structure is used, which reduces the complexity of the array antenna. The operation bandwidth is improved by generating three resonances in the subarray. One 8×8 antenna array is designed, prototyped and tested to exemplify its potential applications in large dual-polarized antenna arrays. A planar orthomode transducer is used to achieve differential excitation for the antenna array. The measured results show that the proposed antenna array has an impedance bandwidth of 19.2–20.7 GHz for |S11| < −10 dB and port isolation higher than 20 dB. The array antenna exhibits a high XPD of 43 dB and a flat gain about 22.2 dBi within the bandwidth

A Low Complexity 16 X 16 Butler Matrix Design Using Eight-Port Hybrids

Beamforming networks such as Butler Matrices are important for multibeam array antenna applications. The challenge for Butler Matrix design is that their complexity increases with the number of ports. In this paper, a novel approach of designing a 16 X 16 Butler Matrix with significant structure simplification is presented. The eight-port hybrids with no crossovers are used to simplify the network. To ensure the network has the same magnitude and phase responses as the standard one, the location and phase shifting value of each fixed phase shifter are derived from the $S$ -matrix of each hybrid. A $16\times 16$ Butler Matrix network operating from 9 GHz–11 GHz is designed to validate this concept. The compensated microstrip 3-dB/90° directional coupler, the phase shifter with a shunt open-and-short stub and the crossover with a resonating patch are used to reduce the transmission loss and enable broadband operation

Wideband Transmitarray With Reduced Profile

This letter presents a wideband transmitarray (TA) with reduced profile. A novel unit cell based on a wideband bandpass filter is developed and applied to the design of the TA. The TA consists of two identical tri-layer frequency selective surfaces (FSS), thus it has a lower profile compared to traditional designs which use at least four FSS layers separated by quarterwavelength air gaps to obtain the 360o phase shift range. The FSS has a pair of square patches printed on the top and bottom layers, and a square slot loaded by four microstrip lines printed on the middle layer. The phase shift is achieved by simultaneously adjusting the size of the square patches. Within the frequency band of interest, the developed unit cell shows low insertion loss and sufficient phase shift range. An equivalent circuit model is developed to better understand the operating principles of the FSS. To validate the design concept, one prototype operating at 13.5 GHz is designed, fabricated and measured. The measurement results show that the designed TA achieves 16% 1-dB gain bandwidth and 60% aperture efficiency. The developed unit cell has symmetric configurations so it can also be applied to the design of dual-polarized or circularly polarized TAs

Ultra-wideband and Multiband Reflectarrays for Intelligent Multi-functional Platforms

This paper includes two parts. In the first part, a review of techniques for designing wideband or multiband reflectarrays is presented. In the second part, two case studies including the designs of one ultra-wideband (UWB) reflectarray and one multi-band reflectarray are presented. The UWB reflectarray is a novel tightly coupled dipole reflectarray (TCDR) whose unit cell is composed of a tightly coupled dipole and a delay line. The minimum distance between adjacent cells is about 1/10 wavelength at the lowest operating frequency. The TCDR operates from 3.4 to 10.6 GHz with stable radiation patterns and aperture efficiency. The multiband reflectarray is a novel dual-band, dual circularly polarized (CP) reflectarray. The dual-band operation of the reflectarray is obtained by using the interleaved circularly polarized triangular patches as the radiating elements. Within each frequency band, two simultaneous shaped beams with different circular polarization and independent control are realized. Both reflectarrays are fabricated and measurement results are presented

Polarization-insensitive wide-angle-reception metasurface with simplified structure for harvesting electromagnetic energy

This paper reports the design, fabrication, and measurement of a metasurface with wide-angle-reception and polarization-insensitive characteristics for harvesting electromagnetic energy. Unlike the metasurface unit cell with multiple vias reported in the literature, it realizes polarization-insensitive characteristics using a single via, which reduces the complexity of the structure significantly. The harvesting and absorption efficiencies at the normal and oblique incidences, energy distribution, and the surface current for different polarization angles are investigated. The simulation results show that the maximum harvesting efficiency is 88% at the center frequency of 5.8 GHz for the arbitrary polarization at the normal incidence of 0°. Within the oblique incidence range of 75°, the maximum efficiency remains higher than 77% for the random polarization. A 5 × 5 array has been fabricated and measured, and the good agreement with the simulated results is obtained

A D-band 3D printed antenna

This paper reports the design and fabrication of a novel all-metal antenna operating in the millimeter-wave band. Based on the resonant cavity antenna (RCA) concept, the principle of antenna operation is explained, and a parametric study of several key design parameters is provided. A novel impedance matching technique is introduced to broaden the antenna return loss bandwidth. Two gain enhancement methods have been employed to achieve a more directive beam with reduced side lobes and back lobes. The D-band antenna prototypes are produced using i) all-metal printing without any post-processing; ii) dielectric printing with copper metallization applied later. Comparisons of the simulated and measured results amongst the antennas fabricated using the two additive manufacturing techniques are made. Measurement results of the two antenna prototypes show that the proposed design can achieve a 14.2% bandwidth with a maximum gain of 15.5 dBi at 135 GHz. The present work is the first D-band resonant cavity antenna fabricated using two different 3D printing methods