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.

UAV-based pattern measurement of the SKALA

Abstract: A novel antenna pattern measurement technique has been recently developed exploiting the capabilities of a micro Unmanned Aerial Vehicle (UAV) as a far-field test-source. This technique is suitable for characterizing VHF antennas such as those for low-frequency radio astronomy. This paper presents some of the measurements recently performed on the Square Kilometer Array Log-periodic Antenna (SKALA), which has been selected as the receiving element for the Low Frequency Aperture Array (LFAA).

Wide bandwidth flat panel antenna array

Abstract: A cavity-backed wideband slimline flat panel antenna array for providing a steerable beam includes an array of slot antennas, each of which fed by its own individual dipole radiator, with the wide bandwidth being due to the matching impedances of the slot antenna and dipole radiator across the entire frequency band. In one embodiment, an upstanding printed circuit balun feed is connected to each dipole. The dipole elements are located to either side of a slot, and are arrayed on the underneath side of a dielectric layer under the substrate into which the slots are formed, with the dipole elements directly fed by individual upstanding printed circuit baluns which are arrayed beneath the individual slots antennas. The use of the dipole elements, in addition to providing a wider operational bandwidth, also permits feeding each of the slots without having to use striplines which would have to cross each other and therefore not work. A wide bandwidth steerable flat panel array utilizing the dipole fed slot antennas may be mounted on the deck house or other flat structural component of a vessel so as to perform a “smart skin” function in which the antenna not only functions as a radiating element, but also as a structural part of the vessel itself. In commercial applications, the flat panel array may be incorporated into the wall of a building such that point-to-point communications between buildings may be accomplished through an antenna which is also a structural part of the building. Note that the beams from the antenna are aimable by appropriately phasing the array to point at a receiving antenna on an adjacent building.

Ground-coupled antenna array for step-frequency GPR

Abstract: This paper describes a new broadband ground coupled antenna array for step-frequency GPR operating continuously over the frequency range from 200 MHz - 3 GHz. The broad frequency range makes the array suitable both for high resolution shallow imaging and deeper investigations where efficient coupling of energy into the ground is crucial. A method for estimating penetration depth based on signal variance is described. The paper contains data examples from the new antenna array and also contains comparison with similar data from an air-coupled bowtie array. Finally, the paper discusses the benefits and disadvantages using air-coupled versus ground-coupled antennas for various applications.

Metamaterial inspired patch antenna miniaturization technique

Abstract: Over the past decade, the need for small, compact and low cost antennas has increased tremendously for applications such as wireless communications and radar. Microstrip patch antennas, though popular for these applications, are difficult to miniaturize, since their resonant frequency is determined by the dominant (TMZ 110 ) mode of the patch cavity (the region immediately beneath the patch). Nevertheless, numerous miniaturization techniques using shorting posts, active loading or high permittivity dielectrics [1] have been conceived to lower the resonant frequency of patch antennas without increasing their size. Unfortunately, as the demand for ever smaller patch antennas increases, these techniques fail to produce the required size reductions.

A 4 watt Ka-band quasi-optical amplifier

Abstract: This paper reports on demonstrated results for a 4 W, 16 dB gain Ka-band Quasi-Optical (QO) amplifier. This amplifier consists of a 13 element two-sided active array with a hard-horn feed. Excess heat is removed via a metal carrier integrated into the array. Each unit-cell consists of patch antennas, cascaded MMIC amplifiers and a unique through-thick-plate coupler. Performance and construction details are discussed. Preliminary results from a 45 element design are also included.