User's Manual

F32700N25.doc Page 4
RJ45 Ethernet 10 Base T Interface Connector
 For further details on the Ethernet Controller, refer to the
Crystal LAN Ethernet Controller Product Bulletin
(CS8900A-EthernetCtrlr.pdf) available on the Product
Documentation CD.
Microcontroller Manages the operation of the radio, the modem, and provides
transmit time-out protection in the event a fault causes the
radio to halt in the transmit mode. Further, uses feedback data
from the base and adjust the frequency to lock to the base
within 0.1 ppm.
Modem Converts serial data into an analog audio waveform for
transmission and analog audio from the receiver to serial data.
Within a single chip it provides forward error detection and
correction, bit interleaving for more robust data
communications, and third generation collision detection and
correction capabilities.
Power Supply The power supply creates the various voltages required by the
digital portion of the fixed radio.
The RF Circuits board contains the following sections:
Transmit Processing Circuitry that amplifies the analog audio signal from the
modem and uses it to modulate the voltage controlled
oscillator (VCO) and 12 MHz reference oscillator in the
injection synthesizer section. Modulating the VCO and
reference oscillator simultaneously results in a higher quality
FM signal.
Injection Synthesizer Provides programmable, ultra stable signals for the radio.
Synthesizer incorporates phase lock loop technology used for
both receiving and transmitting.
Injection In the receive mode, the synthesizer provides a local oscillator
signal of 45 MHz above the selected receive channel
frequency.
Transmitter Consists of an exciter and power amplifier module. The
transmitter covers the various frequency bands in segments.
A different power amplifier module is required for each
segment. The transmitter circuitry includes a T/R switch