User's Manual

10 68P80801E35-A 9/1/2001
Base Radio Exciter EBTS System Manual - Vol 2
Low Noise 800 MHz Exciter
90.3 MHz Voltage Controlled Oscillator (VCO)
The synthesizer within the LNODCT IC sets the 90.3 MHz signal. The 90.3 MHz
VCO provides a LO signal to the LNODCT IC. The LNODCT uses this signal in
up-converting and down-converting the feedback signal.
Regulator Circuitry
The voltage regulators generate three regulated voltages: +3 Vdc, +5 Vdc and
+11.7 Vdc. The regulators obtain input voltages from the +3.3 Vdc and +14.2 Vdc
backplane voltages. The regulated voltages power various ICs and RF devices in
the Exciter.
Linear RF Amplifier Stages
The linear RF ampliers boost the RF signal from the LNODCT IC. The RF
Amplier generates an appropriate signal level to drive the PA.