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The MingantU SpEctral Radioheliograph(MUSER)is comprised of 100 antennas, which is a solar-dedicated radio interferometric array in centimetric and decimetric wave range. This radio heliograph will be optimized to carry out imaging spectroscopy of the Sun with high spatial resolution, high time resolution and high frequency resolution simultaneously. We use MUSER-I and MUSER-II to observe the Sun...
Recent advances in the field of ultra wide band (UWB) localization system has brought renewed interest to the problem of indoor localization system, which has a wide range of applications, such as localization in mine, commodity localization in market or factory and other fields. However, in real scenario, the time synchronization and the limited located users problems are widely existed. An indoor...
A broadband channel sounder measurement campaign was conducted to investigate the ship-to-ship propagation channel in the C-band at 5.2 GHz with a signal of 120 MHz bandwidth. This paper presents details of the measurement campaign. Two scenarios with two vessels in rough sea conditions that either follow or drive towards each other are presented. First results in terms of power delay profile and...
In this paper, near-field antenna probe is designed for propagating spin wave spectroscopy (PSWS) measurement. We compare the meander-line and straight-line antenna probes. Effect of the dimension parameters of antenna probe on scattering parameter is investigated. Near-field distribution and radiation pattern of these two kinds of antenna probe are discussed. Also, the placement of antenna probe...
In this paper, a novel dual circular polarization waveguide antenna array with wide band and low axial ratio is presented at X-band. Planar horn array is used to attain dual circular-polarization working with orthomode transducer and rectangular side wall coupler. A demo array of 16×16 elements is designed, manufactured and tested. The experimental results show that the AR is less than 1.5dB, the...
Obviously, only satellite-based communication systems can supply aircraft with reliable communications in remote airspace. To cope with the rising requirements on data rates, carrier frequencies above 18GHz are considered nowadays. Generally, at these higher frequencies, the effect of ground originated multipath will be less severe due to the spatial discrimination of employed directional antennas...
To investigate into the broadband over water-wave propagation channel, the German Aerospace Center conducted channel sounder measurement where the transmit antenna was mounted on a ship and the receive antenna was located on land. Using this setup, measurements were performed at 5.2 GHz in C-band, with a broadband signal of 100 MHz bandwidth. To analyze the impact on practical communication systems,...
The paper describes a procedure to analyze the statistical variation of the radiation pattern of a monopole antenna mounted on an aircraft using physical optics (PO) in comparison to measurements. In the PO simulations, we use the digital model of a turboprop aircraft to calculate the radiation pattern of the monopole antenna. In order to verify the effect of the aircraft on the antenna radiation...
To investigate the broadband wave propagation channel for communication applications in harbor environments, the German Aerospace Center conducted channel sounder measurements where the transmit antenna was mounted on a ship and the receive antenna was located on land. Using this setup, measurements were performed for C-band at 5.2GHz with a broadband signal of 100MHz bandwidth. Path loss and shadow...
To investigate the broadband over waterwave propagation channel, the German Aerospace Center conducted a channel sounder measurements where the transmit antenna was mounted on a ship and the receive antenna was located on land. Using this setup, measurements were performed at C-band at 5.2GHz with a broadband signal of 100MHz bandwidth. Scattering of the signal due to the roughness of the sea surface...
The aim of the presented activities is to improve the quality and reliability of aircraft bound wide-band satellite transmissions for current and up-coming communication- and air-traffic management applications. To this end, simulation tools are in process of being developed which are based upon an improved model for the transmission channel. Among other influences, the effects of the airborne platform...
A K-band circularly polarized waveguide phased array antenna was designed, fabricated and measured. The measured results show perfect characteristic and verified by the experiment.
To investigate the broadband over sea wave propagation channel for communication and navigation applications, the German Aerospace Center conducted a broadband channel sounder measurements where the transmit antenna was mounted on a ship and the receive antenna was located on the land. Using this setup, measurements were performed for C-band at 5.2GHz with a broadband signal of 100MHz bandwidth. Results...
In this paper, a block of active phased antenna subarray module for the high resolution synthetic aperture radar (SAR) applications was designed, fabricated and measured. The measured results of the module show perfect characteristics and verified by the experiment.
A single-layer right-handed circularly polarized (RHCP) substrate integrated waveguide (SIW) diamond ring-slot antenna at X-band is proposed in this paper. With a shorted diamond ring-slot in the top wall of SIW and a shorting via between the top patch and the bottom ground plane, the RHCP wave and wideband impedance bandwidth are obtained at the same time. The measured impedance bandwidth and axial...
The microstrip antenna is widely used in our life now for its low profile, simple structure, low cost and omnidirectional radiation patterns. But the drawbacks of this kind antenna also sometimes confine their applications, especially the narrow bandwidth. In this paper, a microstrip antenna with the defected ground structure (DGS) is proposed. The bandwidth of an original antenna without DGS is significantly...
We design and evaluate a new type of wireless mesh nodes called Dyntenna nodes that are equipped with steerable omnidirectional antenna. Designed for 3D wireless mesh networks, these nodes adaptively adjust the antenna orientation to increase throughput by improving the Received Signal Strength Indicator (RSSI) reading between nodes. We demonstrate the importance of being able to programmatically...
A flush-disc antenna with a low profile is proposed in this paper. It can get nearly omni-directional radiation patterns and operate over a wide frequency range. The direction of maximum radiation is at 45°. By adding slots and conducting pins on the radiating aperture, the antenna can achieve a wide bandwidth with a low profile structure. The antenna covers a bandwidth from 2.5 to 4.0 GHz. The VSWR...
A general path loss model for in-room radio channels is proposed. The model is based on experimental observations of the behavior of the delay-power spectrum in closed rooms. In such a room, the early part of the spectrum observed at different positions typically consists of a dominant component (peak) that vanishes as the transmitter-receiver distance increases; the late part decays versus distance...
Time Based (TB) localization in terrestrial mobile radio as an augmentation for global navigation satellite systems has recently gained plenty of interests. As an essential tool to develop suitable algorithms for positioning applications in mobile radios, channel models for wireless transmissions have growing significance. Currently there is a lack of investigations on comparing the propagation characteristics...
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