ST ST25RU3993, Руководство пользователя

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UM2268 Reader Settings
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the CCC setting resulting to the absolute lowest reflected power possible. Check that the
other implemented algorithms consider the reflected power suppression be deemed more
important than convergence speed.
– Exact search : This algorithm tries to find an optimized CCC setting (= minimal
reflected power). The algorithm segments the 3-dimensional search-space
(spanned by Cin, Clen and Cout) into a number of equal-sized smaller sub-search
spaces. Then each segment is tuned using FAST (OneHillClimb) in order to find a
CCC setting that results to lower reflected power levels. All the resulting reflected
power levels of each tuned segment are compared against each other. The CCC
setting for which with the overall lowest reflected power can be achieved is
ultimately applied to the tunable capacitors of the CCC.
Note: Although this algorithm has a much higher chance in finding the lowest reflected power
setting, its convergence speed is significantly longer. Especially if both antennas are
activated and the number of transmit frequencies is high (for instance FCC).
– Grouped fast search : This algorithm is based on FAST (OneHillClimb) but
exploits the fact that neighboring frequency channels typically receive similar CCC
settings when tuned. Once being run, the best CCC setting found is copied to
neighboring frequency channels (1 up/1 down for EUROPE, 5 up/5 down for
others frequency profiles).
– Grouped exact search : This algorithm tries to find an optimal CCC setting similar
to the EXACT (MultiHillClimb) algorithm resulting to a minimal reflected power.
Again, the algorithm segments the 3-dimensional search-space (spanned by Cin,
Clen and Cout) into a number of smaller equal-sized sub-search spaces. The
central point of each sub-search space is first tested for the reflected power level.
The FAST algorithm is then only applied those three sub-search spaces that
initially yielded the lowest reflected power. The CCC setting (point in tuner-setting-
space) which has the lowest reflected power is then finally applied to the CCC.
This algorithm has a much higher probability to find the CCC setting with the
lowest reflected power than the FAST algorithm and at the same time is faster
than the exact search algorithm.
– Trench search : This algorithm is a combination of the SLOW and FAST tuning
algorithms. This algorithm first applies the exact search tuning on first frequency
channel. The resulting CCC settings is then used as the starting point for a fast
tuning algorithm which is applied for the next higher frequency channel. The
remaining frequency channels are then also sequentially tuned with the fast tuning
algorithm while the tuning result of the previous frequency channel serves as the
starting point for the current frequency channel to be tuned. This algorithm exploits
the fact that neighboring frequency channels typically have similar CCC settings.
•
Tune : Run tuning process over all channel frequencies of current loaded frequency
channel list.
4.3.2 Automatic PreTuning before Scan panel
•
PreTuning before Scan : Enables the pre-tuning of the carrier cancellation circuit
(CCC). A pre-tuning of the CCC is performed prior any inventory scan. The pre-tuning
is carried out using the parameters listed below:
•
Tuning algorithm : Selects the tuning algorithm which is used for the pre-tuning.
Please refer to Tuning algorithm description in section 4.3.1 Tuning file panel for more
details regarding the various tuning algorithms.