The Linearity Report displays information related to the system non-linearities.
Linearity, 2nd Order (See Mathematical Definitions and Derivations)
The 2nd order Linearity Group displays the 2nd order intermodulation performance of the associated page including linked pages, if any:
OIP2
(Output 2nd order intercept
point) The theoretical output level at which the 2nd order two-tone distortion
products are equal in power to the fundamental output signals.
This number is potentially affected by filters present in the system (See Effective IPx)
IIP2
(Input 2nd order intercept
point) The theoretical input level at which the 2nd order two-tone distortion
products are equal in power to the fundamental input signals. IIP2 is
related to OIP2 by the gain of the component as
This number is potentially affected by filters present in the system (See Effective IPx)
OIM2
The absolute output level
(dBm) of the 2nd order two-tone spurious products.
ORR2
The output rejection
ratio or relative level (dBc) of the 2nd order two-tone spurious products
compared to the desired signals.
IRR2
The amount the input
level must be increased (dBc) to raise the 2nd order spurious products
to the same level as the input before the increase. The initial input
level can be any desired level; however, when the system MDS is the reference
point, the resulting increase is known as the spurious free dynamic range.
SFDR2
Spurious Free Dynamic
Range - The difference between MDS and a two-tone signal level whose 2nd
order IM products are equal to MDS. This is a specific case of IRR2 defined
above.
Linearity, 3rd Order (See Mathematical Definitions and Derivations)
The 3rd order Linearity Group displays the 3rd order intermodulation performance of the associated page including linked pages, if any:
OIP3
(Output 3rd order intercept
point) The theoretical output level at which the 3rd order two-tone distortion
products are equal in power to the fundamental output signals.
This number is potentially affected by filters present in the system (See Effective IPx)
IIP3
(Input 3rd order intercept
point) The theoretical input level at which the 3rd order two-tone distortion
products are equal in power to the fundamental input signals. IIP3 is
related to OIP3 by the gain of the component.
This number is potentially affected by filters present in the system (See Effective IPx)
OIM3
The absolute output level
(dBm) of the 3rd order two-tone spurious products.
ORR3
The output rejection
ratio or relative level (dBc) of the 3rd order two-tone spurious products
compared to the desired signals.
IRR3
The amount the input
level must be increased (dBc) to raise the 3rd order spurious products
to the same level as the input before the increase. The initial input
level can be any desired level; however, when the system MDS is the reference
point, the resulting increase is known as the spurious free dynamic range.
SFDR3
Spurious Free Dynamic
Range - The difference between MDS and a two-tone signal level whose 3rd
order IM products are equal to MDS. This is a specific case of IRR3 defined
above.
Compression
Output P1dB
the system’s
1 dB output compression point in dBm and defined as that output level
which is 1 dB lower than it should be for a corresponding input level
in linear operation (see Mathematical
Definitions and Derivations for more detail).
Input P1dB
the system’s
1 dB input compression point in dBm and defined as the input level that
produces an output 1 dB lower than it should be for linear operation.
In Compression
The number
of dB the system is actually in compression.
Actual Gain
The actual gain
of the system including compression effects.
Linear Gain
The linear gain
of the system with compression ignored. The sum of the “In
Compression” and “Actual Gain”
fields are equal to the “Linear Gain”
field.
Input Backoff (dBm) - The maximum input level that keeps the the component with the most limiting backoff specification just at it's limit. The backoff parameter for at least one component must be enabled. A warning will be issued when the any component's backoff limit is exceeded.
AGC Controlled Range
This group displays the input range that can be controlled by the loop. If the input power is outside of this range, then the defined detector level cannot be maintained. These fields are only displayed when the system has one control loop (i.e., detector).
For intermodulation calculations, SysCalc uses two off-channel tones with spacing Fdel and 2*Fdel from the desired frequency where Fdel is the value entered into this edit field and whose units are kHz. The value entered can be either positive or negative. Since system filters will attenuate the interfering tones, the Effective Intermodulation performance will depend on the interference spacing.
Additional Information
The Linearity Report displays the power level (dBm) present at the system (page) input. If the current system page is linked to a component on a parent page, the input level field shows the power level propagated to the current page from the parent page. The current system temperature is also shown on this report. The system temperature is set in the Project Properties dialog.