3. TECHNICAL BRIEF
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LGE Internal Use Only
Copyright © 01 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3.7.1 Transmitter path
3. TECHNICAL BRIEF
This module features a fully integrated zero IF transmitter. The baseband transmitted data
Is digitally modulated in the modem block and up-converted the 2.4GHz ISM band in the
Transmitter path. The transmitter path consists of signal filtering, I/Q up-conversion, high
-output power amplifier(PA), and RF filtering. It also incorporates modulation schemes
P/4-DQPSK for 2 Mbps and 8-DPSK for 3 Mbps to support enhanced data rate.
• Digital modulator
The digital modulator performs the data modulation and filtering required for the GFSK,
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/4DQPSK, and 8-DPSK signal. The fully digital modulator minimizes any frequency drift
Or anomalies in the modulation characteristics of the transmitted signal and is much more
Stable than direct VCO modulation schemes.
• Power Amplifier
The integrated PA for the BCM2070 is configurable for Class 2 operation, transmitting up to
+4 dBm as well as Class 1 operation and transmit power up to +12 dBm at the chip, gFSK,
>2.5V supply. Due to the linear nature of the PA, combined with some integrated filtering, no
External filters are requires for meeting Bluetooth and regulatory harmonic and spurious
requirements. For integrated mobile handset applications, where Bluetooth is integrated next
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to the celluar radio, minimal external filtering can be applied to achieve near thermal noise
levels for spurious and radiated noise emissions.
Using a highly linearized, temperature compensated design the PA can tr12 dBm for
Basic rate and +10 dBm for enhanced data rates(2 to 3 Mbps). A flexible supply voltage range
Allows the PA to operate from 1.2V to 3.0V. The minimum supply voltage at VDDTF is 1.8V
to a10dBm of transmit power.
3.7.2 Receiver path
The receiver path uses a low IF scheme to down-convert the received signal for demodulation
in the digital demodulator and bit synchronizer. The receiver path provides a high degree of
Linearity, an extended dynamic range, and high order on-chip channel filtering to ensure
reliable operation in the noisy 2.4GHz ISM bnad. The front-end topology, with built-in out
-of-bnad attenuation enables the device to be used in most applications with no off-chip
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-of-bnad attenuation, enables the device to be used in most applications with no off-chip
Filtering. For integrated handset operation where the Bluetooth function is integrated close to
the celluar transmitter, minimal external filtering is required to eliminate the desensitization of
The receiver by the cellular transmit signal.