3.7.7.1 Antenna Damping

A damping function is included in the front end of the ATA8210/15 that can avoid a saturation of the LNAs at high RF signal levels. For more details about the attenuation value of the antenna damping, refer to the ATA8210/ATA8215 UHF ASK/FSK Receiver Data Sheet (9344E), section 4.0, parameter no. 8.80.

The damping block is physically implemented in the SPDT RF switch and affects both receive paths simultaneously. Nevertheless, the function can be enabled and disabled separately for each path.

The antenna damping function must be disabled for both paths if the SPDT switch is unused and the receive antenna is directly connected to the RFIN_LB or RFIN_HB input pins.

If the damping function is enabled, the RF signal level is checked during the RX start-up and every restart of the corresponding path. Upon detection of a saturation condition in the LNA, the damping block is switched ON. If the saturation condition disappeared after a subsequent path restart, the damping block is switched OFF again.

If the damping function is disabled, the RF signal level is not checked during the restart of the corresponding path.

If a Receive mode is started with only one active path, the antenna damping function has to be enabled or disabled for both paths. A mixed configuration is not allowed. If a Receive mode is started with both path A and path B active, any combination of antenna damping disable/enable settings is allowed.

By default, the antenna damping function is enabled for both paths. It can be disabled independently for path A and path B of each service in the eepServices.rxSysSet.AntennaDampingPathx_ENA variables.