Specifications

Rev 2.0 Apr.10 Proprietary and Confidential 97
• Make sure all other wireless devices (Bluetooth or WLAN antennas, etc.) are
turned OFF to avoid interference. For details, see Interference from other
wireless devices on page 42.
Note: System performance below the minimum isolation specification could cause
damage to the module, resulting in below-average system performance.
Peak gain and radiation patterns
Tabl e 1- 7 describes the peak and average antenna gain limits for the main path
and diversity path antennas.
Note: Sierra Wireless recommends using antenna efficiency as the primary parameter for
evaluating the antenna system.
Peak gain is not a good indication of antenna performance when integrated with a host
device; the antenna does
not provide omni-directional gain patterns. Peak gain perfor-
mance can be affected by parameters such as antenna size, location, design type, etc.
The antenna gain patterns remain fixed unless one or more of these parameters change.
Fading correlation coefficient
(MC57xx/MC8201/MC8700/MC878x/MC879x)
Measure the fading (envelope) correlation coefficient between the main and
diversity antennas over the operating Rx frequency bands described in Table 1- 3
on page 92.
The maximum allowed fading correlation coefficient over any of the bands is 0.5.
Table 1-7: Peak and average antenna gain
Antenna
Peak gain
a
a. Vertical/horizontal polarizations
Average gain
b
b. Vertical/horizontal polarizations combined, over 45 in eleva-
tion and
180 in azimuth
Main > +1 dBi > -3 dBi
Diversity > -3 dBi > -6 dBi