Damaskos, Inc. has a large
array of cavities which are used as an alternative to guided line
and freespace methods
of measuring complex dielectric constant (epsilon) and complex permeability
(mu). The general classification of these cavities is; Harmonic
Stripline, Circular, and Thin Sheet Tester. Standard sizes span
different portions of the spectrum from about a few hundred MHz
to about 10 GHz. Typically, the operating bandwidth of a DI cavity
ranges from two octaves to a decade and more. The function of many
of these cavities is to measure low loss epsilon as a combination
of the real part of this parameter and loss tangent-often written
Dk, Df. Some cavities measure both magnetic and dielectric properties.
DI cavities are supported by DI's "Cavity" software package
which performs instrument control of common Agilent and Anritsu
vector or scalar analyzers and data processing on IBM® compatible
or Macintosh® PCs.
Two types of DI resonators
are available; Courtney and Open Resonators. The Courtney resonators
are capable of measuring low loss dielectric materials such as polymers
and ceramics with epsilon values of about 2 to 200. Courtney resonator
measurements are made primarily in the TE01 mode at a single frequency
dictated by epsilon and
the size of the cylindrical sample from as low as about 1 GHz and
up to about 30 GHz. DI Courtney cavities are supported by a suitable
version of "Cavity" software.
The three standard DI
mm-Wave open resonators are used to measure dielectric materials
starting from about 8 GHz up to about 100 GHz, depending upon model.
They measure the in-plane component of epsilon and tandelta of solid
and thin materials in a non-contacting, easy to prepare, manner.
DI's open resonators complement DI's thin sheet testers and DI's
circular cavities which are available in models that operate beginning
at a few hundred MHz and into the microwave band. A suitable version
of "Cavity" software is used with DI's open resonators.