LG KU950 Service Manual page 67

3. TECHNICAL BRIEF
3.11.2. GSM Rejection Filter (FL200)
GSM rejection filter is placed between antenna and tuner. The filter is a type of BPF(Band Pass
Filter) and has pass-band from 470MHz to 702MHz. This filter is used protect DVB-H signal
from GSM interference which is near by DVB-H band. So, the performance of the filter is
decided by attenuation for GSM band.
3.11.3. DVB-H Tuner (U200)
The Microtune® MT2260(U200) is a direct-conversion, low-power single-chip broadband tuner
that has been optimized for UHF and L-Band DVB-H applications. The MT2260 includes all
active circuitry required to implement the complete RF to Baseband tuner function. It is capable
of receiving frequencies in the 470 MHz to 890 MHz range as well as the 1670MHz to 1675
MHz range and of converting a selected channel to balanced baseband I and Q outputs. The
device is completely integrated, with active on-chip components that include:
Variable-gain low-noise amplifier with band selection filters utilizing ClearTune
•
Quadrature mixers that convert the RF signal to balanced baseband I and Q outputs.
•
Programmable variable-gain baseband filters with on-chip calibration.
•
Integrated RF power detector.
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Single-pin external power-down.
•
Integrated frequency synthesis system, including on-chip phase-locked loops(PLLs), VCOs
•
and varactors, to create quadrature local oscillator frequencies from an external crystal with
very low LO antenna leakage.
Two-wire serial control interface that programs the device as well as reads back its status.
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Figure. MT2260 Block Diagram
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TM technology.