Panasonic KX-TG6051BXM Service Manual page 29

4.9.3. 5.8 GHz PA (Power Amplifier), 5.8 GHz LNA (Low Noise Amplifier) and Antenna
Switch Circuit
IC801 includes PA (Power Amplifier) block, LNA (Low Noise Amplifier) Block and Antenna Switch Circuit.
PA block amplifies 5.8 GHz TX signal.
5.8 GHz TX signal from 5.8 GHz RF IC (IC701) is filtered by 5.8 GHz-BPF FL711, and amplified by PA (Power Amplifier) block of
IC801. After that, it is supplied to Antenna Switch block from pin 24 of IC801. V_PA is approximately 4.0 V at base unit, and 3.3 V at
handset.
LNA block amplifies receiving 5.8 GHz signal. 5.8 GHz RX signal from Antenna Switch block of IC801 is amplified by LNA block and
is supplied to IC701 through 5.8 GHz-BPF (FL721).
Antenna Switch block of IC801 switches for RF signals by ANTSEL_A and ANTSEL_B from IC701.
IC701 checks RSSI (Received Signal Strength Indicator), and selects better receiving condition antenna.
At RX mode, RX signal is lead from selected antenna to LNA block.
On the other hand, 5.8 GHz TX signal from PA block is lead to selected antenna at RX mode.
Note:
The exposed GND_PLATE on the bottom of IC801 supplies the circuit ground(s) for the entire chip. It is very important that a
good solder connection is made between this GND_PLATE and the ground plane of PCB underlying the IC801.
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KX-TG6051BXM/KX-TGA601BXM