Power Amplifier; Front Panel - Gigawave D-Cam Clip-On Operator's Manual

5.4 Power Amplifier

The function of the power amplifier is to amplify the signal from the COFDM modulator to a
suitable level for transmission via the N -type connector into the antenna. The amplifier is
required to be highly linear to accommodate the multiple carrier signal formats employed
for digital system operation, with very low distortion (low intermodulation between carriers).
The nominal output power is +20dBm (100mW) across the 2.2 – 2.7GHz band. Nominal
overall gain is 29dB, thus the nominal RF input level is –9dBm. The amplifier operates
from a single +8 Volt supply. Nominal operational supply current is 700mA.
The status of the PA is provided by LEDs to monitor RF output level (green) and DC
present (red) and also monitored by the main controller and displayed as the status
monitoring menu. See 3.3.
To ensure good RF practices when power is applied to the D-Cam Clip -On Camera back,
always make sure that there is a suitable load or antenna connected to the RF output.

5.5 Front Panel

The Front Panel consists of a microcontroller, 16-character by 2-line LCD display, operator
switches and interface circuits.
The Front Panel is the main system controller for the unit. All configuration of the unit
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hardware is from this board. An I C two-wire interface is used to communicate with all
other intelligent devices within the unit. This carries the command data and reads back
status data from all boards within the unit. At power-up this board initialises all the other
boards and during normal operation monitors all the major functions and reports any
problems as part of the unit status.
All configuration parameters, video settings, audio settings, MPEG encoder parameters,
frequencies etc; are held on this board. The MPEG parameter set required (one of sixteen)
is selected via the Front Panel by the operator. These parameter sets are held in the non-
volatile memory of the front panel unit and can only be upgraded by the factory.
D-Cam Clip-On Operators Manual Issue 1 Page 24 of 24
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