Murata Electronics North America Z2430A Manual Do Utilizador

Appendix I  

 

Operating Scenario for ZMN2430A and ZMN2430HPA 

 
The ZMN2430A/HPA is used in a portable network application using Direct Sequence Spread Spectrum 
(DSSS) technology.   The ZMN2430A/HPA is a 

ZigBee device utilizing IEEE 802.15.4 physical layer 

with propriety software to create network infrastructure that is decentralized and inexpensive, as each 
node need transmit only as far as the next node. Nodes act as repeaters to transmit data from nearby nodes 
to peers that are too far away to reach, resulting in a network that can span a large distance, especially 
over rough or difficult terrain. These products may be used as a portable, fixed or mobile device. 
 

Maximum Transmit Duty Cycle  

 

Each ZMN2430A/HPA can transmit a maximum of 4.2 ms per 50 ms.  This is set by design and cannot 
be adjusted by the user. This equals 0.084 ms 
 
Therefore, our source-averaged transmit duty cycle becomes 0.084 
 

Calculated Average Power 

 
The Power Threshold for ‘General Population’ portable designation without SAR testing is: (based 
on Oct 2005 TCB workshop PPT slide) 
 
(60 / F

GHz

) mW for distances < 2.5 cm      

 
For the 2.4 GHz frequency band, this results in a limit of 25 mW.   
 
Note that we use the more restrictive “General Population” limit in this case even though the individuals 
using this product will certainly be aware of its function and would qualify under the ‘occupational’ 
category.  
 
Given the maximum transmit duty cycle specified above, the average transmitted power of a 
ZMN2430HPA and a ZMN2430A remote can be calculated as:  
 
Maximum Pout = 135 mW (21.31 dBm nominal) 
Maximum Antenna Gain = 0 dBi (for portable use) 
Maximum Transmit Duty cycle (per above) = 0.084 
Pave (Source-based average) = 0.135 * 0.084 = 11.3 mW 
 
Maximum Pout = 1 mW (-1.3 dBm nominal) 
Maximum Antenna Gain = 0 dBi (for portable use) integrated antenna   
Maximum Transmit Duty cycle (per above) = 0.084 
Pave (Source-based average) = 0.001 * 0.084 = 0.084 mW 
 
Conclusion: 
 
The ZMN2430A and ZMN2430HPA meets the FCC MPE limits for a ‘Portable’ device operating in the 
‘General Population’.