User's Manual

68P80801E35-B 5/1/2002 11
EBTS System Manual - Vol 2 Base Radio Exciter
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 amplifiers boost the RF signal from the LNODCT IC. The RF
Amplifier generates an appropriate signal level to drive the PA.