User's Manual

APPLICANT: MOTOROLA EQUIPMENT TYPE: ABZ89FC4827
User / Operational Manual
Functional Description / Operation of Modules (Draft)
EXHIBIT D1-6
Exciter Overview
The Transmitter Circuitry comprises two modules, the Exciter Module and the Power Amplifier (PA) Module.
These modules combine to generate, modulate, and amplify the RF signal which is transmitted via the site transmit
antenna.
The Exciter Module interfaces directly to the Station Control Module (SCM), generates a modulated RF signal at
the desired transmit frequency and sends this signal to the PA for amplification. The circuitry operates as follows.
The transmit synthesizer and Voltage-Controlled Oscillator (VCO) circuitry on the Exciter Module accept frequency
programming data from the SCM via the Serial Peripheral Interface (SPI) bus, and generate an RF carrier at the
specified frequency. The VCO is directly modulated by transmit audio / data from the SCM. The resulting
modulated RF signal (at a level of approximately +12 dBm) is then fed to the PA.
The Exciter board contains the following circuitry:
• Frequency Synthesizer Circuitry – consists of a phase-locked loop and Voltage-Controlled Oscillator
(VCO), generates a modulated RF signal at the transmitter carrier frequency
• RF Isolation Switch – allows the SCM to turn on/off the Exciter RF output signal to the power amplifier
module
• Analog to Digital Converter (ADC) Converter Circuitry – converts the analog Exciter status signals to the
digital format for transfer, upon request, to the SCM
• Local Power Supply Regulation/Filtering – accepts +8V, +10V and +14.2V inputs and provides +5V, +10V,
and +12V operating voltages
Input and Output Connections - The following shows the Exciter module input and output external connections.
Specifications of Exciter Module
Parameter Specification
Frequency Ranges 403–470 MHz (UHF R1) or 450–524 MHz (UHF R2)
Electronic Bandwidth Full Bandwidth (UHF R1 and R2)
Output Power 10–14 dBm
Current Draw (Maximum) 0.04A from 14.2 VDC supply
0.15A from 10 VDC supply
0.02A from 8 VDC supply
Harmonics -20 dBc