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To study the Doppler shift phenomenon in the propagation of the short-wave signal in the ionosphere with heated F layer, the ionosphere is divided into two kinds of different parts of the normal ionosphere and the heating ionosphere. Then the expression of Doppler shift can be derived through the two part's motion. In the case of ignoring the influence of electron density with time and geomagnetic...
Time reversal orthogonal frequency division multiplexing (TR-OFDM) has recently been received significant concerns in wireless sensor networks (WSNs) applications for its reliable, high-speed, and green communications in multipath environments. However, most publically reported studies were typically performed in strongly multipath channels. In more general non-rich multipath environments, the TR-OFDM...
In this work, a three-band polarization-independent phase gradient metasurface, whose super cell is composed of six different H-shaped elements placed on the substrate layer with back metallic sheet, is proposed to realize conversion between incident wave and spoof plasmon polariton. The measured results conform to the simulated results that the phase gradient metasurface can couple the x and y polarized...
The features of GNSS ionospheric scintillations were studied by using multi-frequency GNSS measurements at Guilin, China (25.29°N, 110.33°E; geomagnetic: 15.04°N, 181.98°E), a station located near the northern crest of the equatorial anomaly. The results are presented for data recorded by a GPStation6 receiver from July 2015 to June 2016. The results show that amplitude scintillations were observed...
The design of horn antenna loaded with a quasi-period structure is presented in this paper, to achieve higher aperture efficiency. The novel structure is composed of a double-layer metallic holes array. Simulation and experiments show that new design can get more uniform phase distribution than the normal horn without ENZ layer, the gain is enhanced 3dB, and the aperture efficiency is increased from...
Laser sheet is of great practical importance in various fields, such as particle image velocimetry and probe detections. On the contrary to Gaussian beam, laser sheet is the beam focused by a cylindrical lens. In order to better understand the physical mechanism, the paper is devoted to the description of the interaction between a multilayered sphere and a laser sheet beam by using the generalized...
A miniaturized ultra-wideband (UWB) antenna has been designed. It is used for the WLAN with notched band. A circle slot is etched on the radiation patch; a cross strip line is added in the middle of patch. This structure makes antenna with the effect of notch, which can effectively restrain narrowband spectrum interference with WLAN. Using the electromagnetic simulation software, the miniaturized...
This paper aims to design the low sidelobe microstrip array antenna with a certain angle beam which works in Ka-band. By controlling the difference feeding phase shift and space between the units, the beam angle is acquired. At the center frequency of 35 GHz for a patch, the bandwidth is 2.3 GHz, and the gain is 8.17 dBi; The bandwidth of array antenna is 1.54 GHz and the gain is 20.7 dBi, the beam...
For miniaturization the microwave communication equipment, a miniaturized and low cost array antenna is proposed. A 2-layer of patch antenna unit is designed to broaden the bandwidth of the microstrip antenna. The CST MWS is used to simulate and optimize the antenna structure. Based on the designed antenna unit, an array antenna is proposed to achieve high gain, and the simulation and optimization...
A novel method aimed at reducing radar cross section (RCS) of microstrip antenna is presented in this paper. The stopband electromagnetic band-gap (EBG) is used to replace the metallic ground of the proposed antenna to reduce the out-of-band RCS. Meanwhile, the high impedance surface (HIS) is applied to reduce RCS in the operation frequency by canceling out the reflected wave. Thus, a wideband RCS...
In this paper, a wideband segmented line dipole antenna with stable radiation patterns in E-plane was proposed and simulated. The configuration of the segmented line helps to reduc the phase lag of the following current which flows toward the same direction consequently. According to the simulated results, the designed antenna covers a wide impedance bandwidth of about 1.34 GHz (2.16–3.5 GHz, 47%)...
In this paper, we present a meander-line monopole antenna for Unmanned Aerial Vehicle (UVA). In order to improve the resonant characteristic and expand the bandwidth, a couple of coupled patches have been added. It also improves the radiation characteristics in higher frequency. The antenna realizes omni-directional radiation in the horizontal plane when operating in780MHz–900MHz and 1.20GHz–2.28GHz...
A wideband cross dipole with circular polarization and wide beam was presented for satellite-borne application. It consists of two rectangular orthogonal dipoles, a circular parasitic plate, and a grooved ground plane. This proposed antenna is designed to work from 2GHz to 5GHz. Its dimension is Φ1.08λc × 0.41λc, where λc is the wavelength of center frequency. The parasitic plate and grooved ground...
A new filter-antenna for wireless communication was described in this paper. The printed antenna was integrated with a edge coupled filter to get the lower insertion loss. The measured results show that the antenna can operate on 2.34GHz ∼ 2.80GHz with good radiation pattern. The gain of antenna is between 𢀒1dBi and 3.37dBi.
A single-layer differential coplanar waveguide (CPW) fed antenna is proposed for common-mode suppressed and WLAN band notched ultra-wideband (UWB) applications. The UWB nature is generated by the stepped slot radiators and a pair of differential stepped CPW feeding lines. When two ports of the antenna are fed with common-mode signals, the radiator cannot be excited and common-mode suppression is obtained...
This paper studies a simple and novel annular-ring slotted microstrip patch antenna loaded by a surface mount chip capacitor for circularly polarized (CP) radiation. By connecting the capacitor with a proper value across the annular-ring slot at an appropriate position, the fundamental resonant mode of the microstrip patch antenna can be degenerated into two orthogonal modes with equal amplitude and...
A novel high gain bidirectional circularly polarized array with the same rotation direction on both sides is proposed in this paper. The array consists of 4 bow tie antennas and operates at 900 MHz. The 4 bow tie antennas are arranged into two linearly polarized endfire sub-arrays which are placed orthogonally, the elements of the two sub-arrays are separated by a distance of one quarter of the free...
A dual-polarized Yagi-Uda antenna for the passive radar is proposed. The antenna consists of two orthogonally installed Yagi-Uda antennas, each of them responsible for one polarization direction. The measurement result shows that the cross polarization discrimination between the two ports is more than 20dB. Antenna patterns for both polarization directions are the same due to the symmetric structure...
The antenna array with non-symmetric U-strip stubs antennas is proposed for the wideband and omnidirectional radiation. More specifically, single radiation element with four optimized non-symmetric U-strip stubs antennas provides nice bandwidth characteristics. Three same radiation elements with 30 degrees rotated between adjacent ones are configured in vertical direction to compensate for the radiation...
A dual-polarization higher order mode substrate integrated cavity (SIC) antenna array operating in Ka band is proposed. Cross-shaped radiating slots are employed to achieve the dual polarization performance. An 8×8-elements array is designed by using three layers of double-side printed circuit broads (PCBs), which is composed of two layers feeding networks and one layer radiating elements. For better...
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