Designer's Notebook Research Articles

Correction

Christophe Granet has provided a corrected version of Table 2 from the Antenna Designer's Notebook for April (Christophe Granet and Graeme L. James, "Design of Corrugated Horns: A Primer," IEEE Antennas and Propagation Magazine, vol 47, no 2, April 2005, pp. 76-84).

More on warrowband impedance-matching limitations [Antenna Designer's Notebook

Discusses the equation presented by Lopez (2004).

Impedance matching improvement for a class of wideband antennas [Antenna Designer's Notebook

A simple and efficient technique for improving the impedance matching of a class of wideband antennas is presented. These antennas have impedance characteristics that exhibit dual (or multiple) resonance. The results obtained are in good agreement with the experimental test.

Antenna's Designer Notebook

Antenna's Designer Notebook

Beam squint in parabolic reflector antennas with circularly polarized feeds [Antenna Designer's Notebook

The beam squint phenomenon is an important design issue for modern reflector antennas, because it can affect the antenna pointing performance. For long-distance communications, like satellite or deep-space communications, this effect must be care- fully taken into account in order to avoid any degradation. In some design considerations, one may use the squint phenomenon to one's advantage in separating two RHC- and LHC-polarized beams. Squint was previously observed in offset parabolic reflectors with an on-focus circularly polarized feed [l], such as that shown in Figure 1. It must be emphasized that this squint only occurs for antennas with circularly polarized feed, but not for those for which the feed is linearly polarized.

Implementing rationale crew system design through the Designer's Electronic Notebook

The Boeing crew system design system is described. It consists of many separate components intended to provide direction and assistance to the crew system design effort. There are analytical software tools, databases to support design studies and decision-making, test and evaluation tools, and a documented design process. In order to obtain the maximum benefit from such a system, the designer is given guidance in the application of these resources. The Designer's Electronic Notebook (DEN) has been developed to supply this assistance by guiding the designer through the design process, providing step-by-step design procedures, and directing the designer to the appropriate databases, tools, references, and resources. A description is given of the DEN and how it can aid the designer. Implementation factors, examples of its displays, and the benefits of using the DEN are presented. >

Antenna designer's notebook

Antenna designer's notebook

Space Attenuation Chart [Antenna designer's notebook

This graph provides a new convenient display of attenuation between antennas as a function of freouency and antenna separation in meters, feet, or miles (Friis transmission equation). Distances covered are 10 feet to more than 1000 miles in the frequency range of 10MHz to above 100GHz.

Antenna designer's notebook

Antenna designer's notebook

Antenna designer's notebook

The Scalar Feed was first conceived in 1962. This article reviews the development process, as well as the fundamental properties and limitations of the device, which eventually became known as the corrugated conical horn.

Antenna designer's notebook

Antenna designer's notebook

Antenna designer's notebook

Antenna designer's notebook

Antenna designer's notebook

Last year in our June 1987 issue, Gerry Seck presented a curve (and its derivation) giving the reduction in gaifno r circular aperture with a quadratic phase distribution. This was for a uniformly illuminated aperture. Since then, two of our members have commented on this contribution, and have added further insight into the subject.

Antenna designer's notebook

Small linear arrays of dipoles, with and without reflecting screen, are sometimes used for hf broadcasting, or at higher frequencies for ECM and other applications. When the scan is in the plane in which the element pattern has directivity, or when a backscreen is used, the element pattern will affect the angle of the maximum radiation, especially for very small arrays. This item presenrtess ults for collinear Eplane arrays of half-wave dipoles, with and without a backscreen.

Antenna designer's notebook

Antenna designer's notebook

Antenna designer's notebook

The polarization requirements of EW and other systems often dictate that the antenna be capable of multiple polarizations, for example vertical, horizontal, and both senses of circular, i.e. V, H, RHCP, and LHCP. In some instances a fixed linear polarization such as +45° tilted linear can be used, but its response to the other polarizations involves polarization mismatch losses as shown in Table 1. Note that most combinations have a 3dB loss, and that +45° is "blind" to a co-polarized source. In cases where the 3dB loss is not tolerable, the antenna must generate the desired polarizations in a simple and cost effective manner.

Antenna designer's notebook

Antenna designer's notebook

Antenna designer's notebook

Antenna designer's notebook

Antenna designer's notebook

Antenna designer's notebook

Antenna designer's notebook

Antenna designer's notebook