Library Block
Library blocks are parameterized blocks based on a numerical simulation. In general, a library block implements a well-known and often used structure that cannot be handled by analytical methods. A library block can only be associated with a CST MICROWAVE STUDIO® project file.
The files describing a library block are installed in a special library path of your installation. There is one file that stores information about the contents of the entire library.
Library elements support interpolation of S-parameter and impedances. The settings for interpolation can be accessed through the Block Properties - Solver dialog box. If interpolation is used for the first time, it may be necessary for CST MICROWAVE STUDIO® to calculate a view that samples points. The number of necessary sampling points depends on the number of changed parameters. If only one parameter is changed, three sampling points are calculated and the result is interpolated between them. In general 2N+1 Sampling points are needed, where N is the number of changed parameters. Because of the result cache, the calculation of sampling points is performed only once for values that lie between them. Small changes of the parameter are then calculated very quickly.
If a parameterized CST MICROWAVE STUDIO® structure is used more than once in your design, it is recommended that you use it as a library block.
Library blocks are stored inside a global repository. They can be used like an analytical block. In contrast to a CST MICROWAVE STUDIO block, the associated project can no longer be modified.
The library
can be shared among users. To gain access to a library, specify its path
within the Library Paths
dialog box that is opened by choosing 
File:
Options Library
Paths. However, you will not only access the library
elements stored there, but also macros, templates, etc. that are available
from that repository.
Results calculated
for different parameter combinations are stored for every library element
in the global repository (cache). As explained for the CST
MICROWAVE STUDIO block, several caches may
be used simultaneously. Therefore, specify their paths within the Cache
Paths dialog box that is opened by choosing Home:
Edit Result
Cache Set Cache
Path.
As far as the cache management is concerned, there is a significant difference between a library element and a CST MICROWAVE STUDIO block’s associated project: Once a library element is defined, the solver and mesh type for this element are fixed. As a result, all cache entries refer to these settings.
To insert a library block into the current design, find its symbol in the ’Miscellaneous’ section of the block selection tree, drag to the schematic view and drop it there. After it is dropped, the Select Library Element dialog box will appear. There, the desired library element can be selected.
Note: Library blocks are always frequency bounded which may change if some parameters are modified (as for an analytical block as well).
To summarize, a library block can be used like an analytical block. Each element provides a global cache that can be accessed by all blocks of this type.
See also