5.1.5 Receiver Blocking and Selectivity Characteristics

This section describes the blocking behavior of the ATA8210/15. The numbers listed are the 3 dB blocking characteristics. The measurements below are carried out with a useful signal at a frequency of fRF and a level of 3 dB above the BER = 10-3 sensitivity levels. For more details, refer to the ATA8210/ATA8215 UHF ASK/FSK Receiver Data Sheet (9344E), section 4, parameter numbers 4.90-5.20. The values indicated describe how much a continuous wave disturber can be larger than these useful signal levels until the BER drops back to 10-3. For example, the sensitivity level is -106.5 dBm, and, at a distance of 1 MHz, the blocking is 64 dBC (see the following figure). For more details, refer to the ATA8210/ATA8215 UHF ASK/FSK Receiver Data Sheet (9344E), section 4, parameter numbers 5.10 and 7.10. The useful signal applied in the measurement is -106.5 dBm + 3 dB = -103.5 dBm and the measured absolute blocker level for BER 10-3 is -103.5 dBm + 64 dBC = -39.5 dBm.

The following figures illustrate the blocking behavior for 433.92 MHz with 165 kHz bandwidth using FSK modulation with a data rate of DR = 20 kBit/s and a frequency deviation of fDEV = ±20 KHZ. See Measured Blocking at ±10 MHz Frequency Offset (fRF = 433.92 MHz, BW = 165 kHz, FSK, DR = 20 kBit/s, fDEV = ±20 kHz) and Measured Blocking in the Frequency Range from 100 MHz to 900 MHz (fRF = 433.92 MHz, BW = 165 kHz, FSK, DR = 20 kBit/s, fDEV = ±20 kHz) in the Receiver Blocking and Selectivity Characteristics from Related Links.

Note: All measurements are with high resolution to capture all spurious receiving frequencies.
Figure 5-9. Measured Blocking at ±1 MHz Frequency Offset (fRF = 433.92 MHz, BW = 165 kHz, FSK, DR = 20 kBit/s, fDEV = ±20 kHz)
Figure 5-10. Measured Blocking at ±10 MHz Frequency Offset (fRF = 433.92 MHz, BW = 165 kHz, FSK, DR = 20 kBit/s, fDEV = ±20 kHz)
Figure 5-11. Measured Blocking in the Frequency Range from 100 MHz to 900 MHz (fRF = 433.92 MHz, BW = 165 kHz, FSK, DR = 20 kBit/s, fDEV = ±20 kHz)

For more details on the differences in the blocking characteristics for other RF or bandwidths, refer to the ATA8210/ATA8215 UHF ASK/FSK Receiver Data Sheet (9344E), section 4, parameter numbers 6.90-7.80. To describe the differences more clearly, the blocking for 25 kHz IF bandwidth and 360 kHz IF bandwidth, see the following figure.

Figure 5-12. Measured Blocking at ±1 MHz Frequency Offset (fRF = 433.92 MHz, BW = 25 kHz, FSK, DR = 2.4 kBit/s, fDEV = ±2.4 kHz)

To describe the differences more clearly, the blocking for 25 kHz IF bandwidth and 360 kHz IF bandwidth, see the following figure.

Figure 5-13. Measured Blocking at ±1 MHz Frequency Offset (fRF = 433.92 MHz, BW = 366 kHz, FSK, DR = 20 kBit/s, fDEV = ±20 kHz)