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3. TECHNICAL BRIEF
3.5.7. UMTS Rx RF Filter(FL104 : EFCH2140DE1)
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 cross-modulation threat in combination with Rx-band jammers. The RF filter must
provide rejection of this Tx-band leakage.
-. Other frequencies of particular concern . bands known to include other wireless transmitters that
may deliver significant power levels to the receiver input.
Table 3.5.7 UMTS Rx SAW Filter Specification