S1M8660A Datasheet, PDF (16/32 Pages) Samsung semiconductor – RX IF / BBA WITH GPS

S1M8660A (Preliminary)
RX IF/BBA WITH GPS
Rx Low-Pass Filters
The CDMA baseband signal frequency can range between 1kHz to 630kHz. Normally, the range between 1kHz
to 615kHz is called the In-band, between 630kHz to 750kHz Band-edge, and anything outside of these ranges out
band. Very precise characteristics are required in the in-band range. The ripple, I/Q gain-phase error are critical
factors that lead to noise in the in-band. FM Baseband signal ranges between 100Hz to 15kHz. Normally, the
frequency range between 100Hz to 12kHz is called the in-band, between 12kHz to 18kHz the band-edge, and
anything outside of these ranges the out-band. As for the CDMA, the ripple, I/Q gain-phase error are critical
factors that lead to noise in the in-band.
The LPF characteristic required by these three systems are shown in Figures.
+1.5dB
+0.5dB
-1.5dB ⁰
-4.0dB
-46.0dB
-48.0dB
1kHz
600kHz 750kHz 1.2MHz
630kHz 900kHz
Frequency
Figure 8. CDMA Rx Low-Pass Filter Masks
+0.5dB
-0.5dB
-3.0dB
-60.0dB
100Hz
12.2kHz
60kHz
18kHz
Frequency
Figure 9. FM Rx Low-Pass Filter Masks
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