16-05-2013, 04:19 PM
LRR- LINE REFLECT REFLECT
LRR- LINE REFLECT.doc (Size: 193.38 KB / Downloads: 14)
INTRODUCTION
LRR- LINE REFLECT REFLECT is a new self-calibration
procedure for the calibration of vector network analyzers (VNA). VNA
measure the complex transmission and reflection characteristics of
microwave devices. The analyzers have to be calibrated in order to
eliminate systematic errors from the measurement results.
The LRR calibration circuits consist of partly unknown standards,
where L symbolizes a line element and R represents a symmetrical
reflection standard. The calibration circuits are all of equal mechanical
length. The obstacle, a symmetrical-reciprocal network is placed at three
consecutive positions. The network consists of reflections, which might
show a transmission. The calibration structures can be realized very easily
as etched structures in microstrip technology.
VECTOR NETWORK ANALYZERS
It measures the complex transmission and reflection characteristics
of microwave devices. This is achieved by comparing the signal input to the
device, with the signal either transmitted through or reflected back from the
device. They incorporate very narrow bandwidth receivers tuned to the
signal source frequency and give a direct readout of the four coefficients
contained in a scattering matrix-the scattering or ‘s’ parameters, each of
which has magnitude and phase elements. The network analyzer was
controlled by an external personal computer. The raw measurement data
have been read out and processed on a computer.
MICROSTRIP LINES
Prior to 1965 nearly all microwave equipment utilized coaxial,
waveguide, or parallel strip-line circuits. In recent years microstrip lines
have been used extensively because they provide one free and accessible
surface on which solid state devices can be placed. It is an unsymmetrical
stripline, that is a parallel plate transmission line having dielectric substrate,
one face of which is metalised ground and the other(top) face has a thin
conducting strip of certain width ‘w’ and thickness ‘t’. Sometimes a
coverplate is used for shielding purposes but it is kept much farther away
than the ground plane so as not to affect the microstrip field lines. It is also
called an open strip line. Modes on microstrip are only quasi transverse
electromagnetic (TEM). Thus the theory of Tem- coupled lines applies only
approximately.
Microstrip transmission lines consisting of a conductive ribbon
attached to a dielectric sheet with conductive backing are widely used in
microwave technology. Because such lines are easily fabricated by printed-
circuit manufacturing techniques, they have a technical merit. Most
microstrip lines are made from boards of copper with a thickness of 1.4 or
2.8 mils. Line width of less than 0.1 is uncommon.
LRR- LINE REFLECT.doc (Size: 193.38 KB / Downloads: 14)
INTRODUCTION
LRR- LINE REFLECT REFLECT is a new self-calibration
procedure for the calibration of vector network analyzers (VNA). VNA
measure the complex transmission and reflection characteristics of
microwave devices. The analyzers have to be calibrated in order to
eliminate systematic errors from the measurement results.
The LRR calibration circuits consist of partly unknown standards,
where L symbolizes a line element and R represents a symmetrical
reflection standard. The calibration circuits are all of equal mechanical
length. The obstacle, a symmetrical-reciprocal network is placed at three
consecutive positions. The network consists of reflections, which might
show a transmission. The calibration structures can be realized very easily
as etched structures in microstrip technology.
VECTOR NETWORK ANALYZERS
It measures the complex transmission and reflection characteristics
of microwave devices. This is achieved by comparing the signal input to the
device, with the signal either transmitted through or reflected back from the
device. They incorporate very narrow bandwidth receivers tuned to the
signal source frequency and give a direct readout of the four coefficients
contained in a scattering matrix-the scattering or ‘s’ parameters, each of
which has magnitude and phase elements. The network analyzer was
controlled by an external personal computer. The raw measurement data
have been read out and processed on a computer.
MICROSTRIP LINES
Prior to 1965 nearly all microwave equipment utilized coaxial,
waveguide, or parallel strip-line circuits. In recent years microstrip lines
have been used extensively because they provide one free and accessible
surface on which solid state devices can be placed. It is an unsymmetrical
stripline, that is a parallel plate transmission line having dielectric substrate,
one face of which is metalised ground and the other(top) face has a thin
conducting strip of certain width ‘w’ and thickness ‘t’. Sometimes a
coverplate is used for shielding purposes but it is kept much farther away
than the ground plane so as not to affect the microstrip field lines. It is also
called an open strip line. Modes on microstrip are only quasi transverse
electromagnetic (TEM). Thus the theory of Tem- coupled lines applies only
approximately.
Microstrip transmission lines consisting of a conductive ribbon
attached to a dielectric sheet with conductive backing are widely used in
microwave technology. Because such lines are easily fabricated by printed-
circuit manufacturing techniques, they have a technical merit. Most
microstrip lines are made from boards of copper with a thickness of 1.4 or
2.8 mils. Line width of less than 0.1 is uncommon.