Reflective array antenna

About: Reflective array antenna is a research topic. Over the lifetime, 4366 publications have been published within this topic receiving 57884 citations.

The electrically small magnetically loaded multiturn loop antenna

Abstract: An analytical model of a class of electrically small multiturn loop antennas has been formulated and compared with experimental measurements over a frequency range of 3 to 86 MHz. Both air core and magnetically loaded eases were examined. Transmitted signal enhancement as high as 10 dB was predicted and observed by magnetic loading. Several interesting properties of the transmitting antenna were investigated experimentally and by analysis based upon the model. It is concluded that transmitted signals can be enhanced in the 2-30 MHz range, at reasonable power levels, as much as 10 dB with state-of-art ferrite materials. Secondly, the analytical model described in this paper should prove an effective design aid for a volumetrically constrained antenna of the class.

Extending the R-2R lens to 360°

Abstract: The R.2R lens is a remarkable microwave device that provides perfect focusing, giving multiple simultaneous antenna beams from a circular or cylindrical array. However, the perfect focusing of the R-2R brings with it a serious limitation on angular coverage as a result of the angular doubling that enters when the array elements in the antenna are connected to the launcher elements on the lens periphery. We have now found a way to modify the R-2R concept so that a full circle of array elements can be mapped onto a full circle of beam ports. The new mapping makes use of hybrid junctions and either four or six physical lenses. The interconnections result in 360\deg of simultaneous antenna beams, each of which can be used both for transmission and for reception.

Improved genetic algorithm for the configuration optimization of the sub arrays in phased array radar

Abstract: As the dramatic development of the electronic technology, many of the traditional radar system has been threaten in the modern war. Therefore, we need new technology to overcome all these kinds of problems. The phase array radar is a good solution to all these problems. The phase array radar is constructed of many antenna elements and each antenna element has its own phase shifter. However, the phase array always have a huge amount of money spent on the hardware. This is because each antenna has its own receive path. In order to reduce the hardware cost, we propose a novel algorithm to divide the phase array into the sub arrays. In addition, in order to make the operation be easier, the antenna elements of the sub array should be relatively centered. The simulation results shows our proposed algorithm works well.

Measured vehicular antenna performance

Abstract: Power gain radiation patterns of mobile antennas mounted in six different locations on a test vehicle were measured with and without typical lights and sirens mounted on the roof. The measurements were performed at frequencies representing the frequency bands of 25 to 50, 150 to 174, 400 to 512, and 806 to 866 MHz. In addition, special antennas consisting of three disguised antennas operating at discrete frequencies of 40.27, 162.475, and 416.975 MHz and one slot antenna operating at 413 MHz were also measured. Plots of power gain radiation patterns are given for the mobile antennas mounted in six different locations on the test vehicle and for the special antennas. Results showing the effects of poor grounding characteristics are also included. Recommended locations for mounting the mobile antennas are given for specific frequency bands.

A wide-band hybrid antenna for use in reverberation chambers

Abstract: This paper describes the design and performance of a wide-band hybrid antenna suitable for use in reverberation chambers. The antenna is characterised over the frequency range 100 MHz to 25 GHz showing that it performs well above 200 MHz although its ultimate highest operating frequency has not been established.