Broadband Complex Dielectric Permittivity of Porous Aluminum Silicate–Pyrolytic Carbon Composites

$48.00 plus tax (Refund Policy)

Download / Buy Article:

Abstract:

The broadband (10 kHz–18 GHz) complex dielectric permittivity of electrically lossy aluminum silicate–pyrolytic carbon composites is studied as a function of carbon content. The composites are made from a commercial machinable ceramic that is treated by oxalic acid refluxing, followed by sucrose pyrolysis within the open porosity. The resulting composites have a slightly percolating conductor configuration that exhibits non-Debye dielectric properties. Such composites are useful as microwave absorbers in vacuum electronic amplifiers, for suppressing spurious oscillations, and for bandwidth control. Four contributions to the dielectric response were observed and analyzed. These consist of a direct current conductivity contribution that is significant only at frequencies below 1 MHz, an irregular low-frequency relaxation, a strong non-Debye, high-frequency relaxation with its upper portions extending into the microwave regime, and an underlying, broadband loss consistent with a universal dielectric response. The microwave behavior is dominated by changes in the position, intensity, and Cole–Cole exponent of the high-frequency relaxation as the carbon content increases.

Document Type: Research Article

DOI: http://dx.doi.org/10.1111/j.1551-2916.2005.00435.x

Affiliations: Naval Research Laboratory, Washington, District of Columbia 20375

Publication date: August 1, 2005

Related content

Tools

Favourites

Share Content

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more