The LTC5532 can be used for RF power detection and
control. Figure 2 is an example of a transmitter power
controller, using the LTC5532 with a capacitive tap to the
power amplifier. A 0.5pF capacitor (C1) followed by a
200W resistor (R1) form a coupling circuit with about
20dB loss at 900MHz referenced to the LTC5532 RF input
pin. In the actual product implementation, component
values for the capacitive tap may be different depending on
parts placement, PCB parasitics and parameters of the
antenna.