GatesAir Inc. CZF Manual De Usuario
APEX
™
Exciter Incorporating FLO
™
Technology
Introduction
Technical Overview
Page: 1-4
888-2604-001
03/08/07
WARNING: Disconnect primary power prior to servicing.
1.4
Technical Overview
The exciter accepts an ASI transport stream. The modulation process is fully digital, with
analog circuits used after the D/A converter to up-convert the IF signal to the desired
channel.
analog circuits used after the D/A converter to up-convert the IF signal to the desired
channel.
For operation in the US, the exciter RF output can be set to any one of eight 6 MHZ wide
UHF channels which cover a frequency span from 698 MHz to 746 MHz. The eight RF
channels are referred to as FLO RF Channel 1 through 8.
UHF channels which cover a frequency span from 698 MHz to 746 MHz. The eight RF
channels are referred to as FLO RF Channel 1 through 8.
For operation in other markets, the exciter supports bandwidths of 5, 6, 7 and 8 MHz and
supports center frequencies over a band of frequencies from 470 to 862 MHz.
supports center frequencies over a band of frequencies from 470 to 862 MHz.
The RF output may be adjusted up to 250 mW average power.
The analog chassis can accept a 10 MHz external frequency standard and a 1PPA (1 pulse
per second signal from a GPS receiver) input via a rear-panel connectors. A 10 MHz
external standard is used whenever the user requires either greater frequency precision. An
External 1PPS input along with the 10 MHz input provides greater frequency precision and
or accurate super frame timing (for use with wide area single frequency network
operation).
per second signal from a GPS receiver) input via a rear-panel connectors. A 10 MHz
external standard is used whenever the user requires either greater frequency precision. An
External 1PPS input along with the 10 MHz input provides greater frequency precision and
or accurate super frame timing (for use with wide area single frequency network
operation).
The exciter uses RTAC™ (Real Time Adaptive Correction) to monitor and manage pre
correction for the transmitter system linear and nonlinear distortions, no manual correction
circuits are employed. Low power RF samples from various stages of the transmitter are
required by the RTAC circuits.
correction for the transmitter system linear and nonlinear distortions, no manual correction
circuits are employed. Low power RF samples from various stages of the transmitter are
required by the RTAC circuits.
1.5
Specifications
Specifications for the exciter are listed in Tables 1-1, 1-2, and 1-3.
Note
Specifications subject to changed without notice.
Table 1-1 Harris APEX
Exciter General Specifications
Specification
Explanation
RF output connector
SMA, 50 ohm impedance
RF sample, from the high power filter output
SMA, 50 ohm impedance, exciter input level: -30 to 0 dBm
RF sample, from the power amplifier output
SMA, 50 ohm impedance, exciter input level: -30 to 0 dBm
RF sample, IPA, not used.
SMA, 50 ohm impedance
Frequency range
Within US
FLO RF Channel 1 through 8, 6 MHz channels, 698 to 746 MHz
In Other Markets
6, 7, or 8 MHz channels, from 470 to 862 MHz
Transport stream
input
input
Data Input 1, low priority
ASI, BNC Female, 75 ohms, 270Mbps, Standard = EN 50083-9
Data Input 2, high priority
10 MHz Reference input
BNC, 50 ohms, 10 Mhz, sinusoidal, 0 to +10 dBm, > 20 dB return
loss,
loss,
1PPS (pulse per second) input
Input is high impedance or 50 ohm, +5V TTL, triggers on rising
edge
edge