acpm-7813 Avago Technologies, acpm-7813 Datasheet - Page 16

• Manufacturer Part Number: acpm-7813
• Description: Cdma/amps Power Amplifier Module
• Manufacturer: Avago Technologies

The meaning of 16 dB
The accurate ACPR measurement using Spectrum
Analyzer needs to consider the normalization factor
that is dependent on the Resolution Bandwidth, RBW,
settings. The above figure (measurement shown at
836 MHz for general example) shows a comparison of
the different ACPR measurement results as a function
of various RBW values. As the RBW is reduced, less
power is captured during the measurement and
consequently the channel power is recorded as a
smaller value. For example, if the main channel power
is measured as 28 dBm in a 1.23 MHz bandwidth, its
power spectral density is 28 dBm/1.23 MHz, which can
be normalized to 11.87 dBm/30 kHz. The equation used
to calculate the normalization factor of power spectral
density is:
Normalization Factor =
10log[Normalization BW/Current BW
(Spectrum Analyzer RBW)]
= 10log[1.23X10
= 16.13 dB
Since the ACPR in an IS95 system is specified in a
1.23 MHz bandwidth, a channel power that is measured
using a different RBW, can be normalized to reflect the
channel power as if it was measured in a 1.23 MHz
bandwidth. The difference in channel power measured
in 30 kHz bandwidth and the channel power measured
in a 1.23 MHz bandwidth is 16 dB.
16
ACPR Test Results using Spectrum Analyzer
Figure 21. Example ACPR measurement using Spectrum Analyzer.
Center 836 MHz
REF 42.8 dBm
AT 30 dB
6
/30X10
3
]
VBW 100 kHz
RBW = 30 kHz
RBW = 1.0 MHz
RBW = 300 kHz
Mkr 836 MHz
35.42 dBm
Span 5.000 MHz
SWP 2.00 sec
ACPM-7813 Demoboard Operation Instructions
1) Module Description
The ACPM-7813 is a fully matched Power Amplifier.
The sample devices are provided on a demonstration
PC Board with SMA connectors for RF inputs and
outputs, and a DC connector for all bias and control I/
O’s. Please refer to Figures 22 through 25 and the Pin
configuration table for I/O descriptions and
connections.
Vdd2
Figure 22. ACPM-7813 Evaluation Board Schematic and Layout.
2.2 µF
RF Out
4700 pF
GND
GND
RFout
GND
Vdd2
GND
Vbias
Vcntl
Vdd1
GND
RFin
470 pF
4700 pF
470 pF
2.2 µF
Vcntl
RFin
Vdd1
Vbias