User's Manual

RF Power Amplifiers
Andrew Corporation – Power Amplifier Group
Propriety – Use pursuant to Company Instruction
Page 2 of 2
Introduction
This document presents a description of the Andrew Digital Multi-carrier Amplifier Unit
(DMAU). The DMAU is a 60 Watt (RF), high efficiency base-station amplifier. It accepts as
input a digital representation of multiple CDMA carriers and produces a multi-carrier RF signal at
its output. The amplifier transmits RF power over a 20MHz instantaneous bandwidth within the
US PCS frequency band of 1930MHz to 1990MHz. Up to 15 CDMA2000 carriers or 4 WCDMA
carriers can be transmitted by the DMAU within the instantaneous bandwidth.
Since the DMAU has been designed for cellular base-station use, it satisfies all relevant
transmission requirements, such as spectral mask limits and emission limits called for by the
3GPP2 and 3GPP standards. At rated power and multiple carrier operation, the in band transmit
port emissions are below –13dBm/1MHz for all carrier combinations and counts.
DMAU Specifications
Table 1 below highlights some of the key design specifications that the DMAU satisfies.
Table 1: Key DMAU Specifications
1) Input Signal: Multi-Carrier CDMA2000 or WCDMA (Channel Occupied Bandwidth:
CDMA2000-1.25MHz, WCDMA-4.21MHz) presented as digital data.
2) Input Signal Format: Multi-Carrier Digital Baseband (Separate I and Q signals over 600Msps
LVDS)
3) Overall DC-to-RF efficiency: 14% at 26VDC input and 60WRF output
4) Output Power: 60 Watts total average power.
5) Nominal Input Voltage: +26VDC (+36VDC max for no failure, transmission stops at 32VDC)
6) System Communication Port: 100-base-T Ethernet
7) Operating Temperature Range: -40°C to +55°C
8) Weight: 9Kg; Dimension: 41.51mm(W) x 461mm(D) x 458.83mm(H)
9) Environmental: Sealed for Outdoor Air Cooling
DMAU Interface
There are a total of six external interfaces to the DMAU. A description of each interface is
provided below.
1) Digital Input Port
– Accepts Digital data stream representing multiple carriers of CDMA2000
or WCDMA.
2) RF Output Port
– Main RF output. 60W average power is delivered across 1 to 15
CDMA2000 carriers or 1 to 4 UMTS carriers.
3) Front Panel Debug Port
– RS232 port used for craft access.
4) DC Input Port
– +26VDC input port with approximately 16ADC current draw at rated power.
5) Transmit On/Off Switch
– A mechanical reset switch used to turn off transmit power(not DC),
or to force DMAU into software reset. Located on the front panel.