Simoco SRM9020 - Figure 3-2 VHF;UHF Transmitter Block Diagram

DRAFT D
TNM-M-E-0001 Page 16
Figure 3-2 VHF/UHF Transmitter Block Diagram
An active filter comprising Q14, 17,18 and 19 provides isolation to minimise power supply noise
at the PA. This is achieved by maintaining a voltage differential of approximately 1V across Q14
and indirectly filtering its gate voltage. Q14 is switched on only during transmit via R523 to
minimise receiver power requirements.
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