LG KF390, Руководство по обслуживанию

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3.5.7 UMTS Rx RF filter (FL1001 : EFCH2140TDE1)
An RF filter is located between the UMTS LNA and mixer. Insertion loss is important, but not as critical
as losses before the LNA. The most important parameters of this component include:
■
Out-of-band rejection or attenuation levels, usually specified to meet these conditions:
■
Far out-of-band signals - ranging from DC up to the first band of particular concern and from the last
band of particular concern to beyond three times the highest passband frequency.
■
Tx-band leakage - the transmitter channel power, although attenuated by the duplexer, still presents
a crossmodulation threat in combination with Rx-band jammers. The RF filter must provide rejection
of this Txband leakage
■
Other frequencies of particular concern . bands known to include other wireless transmitters that
may deliver significant power levels to the receiver input.
3. TECHNICAL BRIEF
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[Table 1.3] UMTS Rx SAW Filter Specification
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