CN-0187 Datasheet, PDF (6/7 Pages) Analog Devices – Crest Factor, Peak, and RMS RF Power Measurement Circuit Optimized for High Speed, Low Power, and Single 3.3 V Supply

CN-0187
Equipment Needed
• PC with a USB port and Windows® XP or Windows Vista®
(32-bit), or Windows® 7 (32-bit)
• EVAL-CN0187-SDPZ circuit evaluation board
• EVAL-SDP-CB1Z SDP evaluation board
• CN0187 evaluation software
• Power supply: +6 V, or +6 V “wall wart”
• RF signal source
• Coaxial RF cable with SMA connectors
Getting Started
Load the evaluation software by placing the CN0187 Evaluation
Software disc in the CD drive of the PC. Using "My Computer,"
locate the drive that contains the evaluation software disc and
open the Readme file. Follow the instructions contained in the
Readme file for installing and using the evaluation software.
Functional Block Diagram
See Figure 1 of this circuit note for the circuit block diagram,
and the “EVAL-CN0187-SDPZ-SCH” pdf file for the circuit
schematics. This file is contained in the CN0187 Design
Support Package.
Setup
Connect the 120-pin connector on the EVAL-CN0187-SDPZ
circuit board to the connector marked “CON A” on the
EVAL-SDP-CB1Z evaluation (SDP) board. Nylon hardware
should be used to firmly secure the two boards, using the holes
provided at the ends of the 120-pin connectors. Using an
appropriate RF cable, connect the RF signal source to the
EVAL-CN0187-SDPZ board via the SMA RF input connector.
With power to the supply off, connect a +6 V power supply to
the pins marked “+6 V” and “GND” on the board. If available, a
+6 V "wall wart" can be connected to the barrel jack connector
on the board and used in place of the +6 V power supply.
Connect the USB cable supplied with the SDP board to the USB
port on the PC. Note: Do not connect the USB cable to the mini
USB connector on the SDP board at this time.
Test
Apply power to the +6 V supply (or “wall wart”) connected to
EVAL-CN0187-SDPZ circuit board. Launch the evaluation
software and connect the USB cable from the PC to the USB
mini-connector on the SDP board. The software will be able to
communicate to the SDP board if the Analog Devices System
Development Platform driver is listed in the Device Manager.
Once USB communications are established, the SDP board can
now be used to send, receive, and capture serial data from the
EVAL-CN0187-SDPZ board.
Circuit Note
The data in this circuit note were generated using a Rohde &
Schwarz SMT-03 RF signal source and an Agilent E3631A
power supply. The signal source was set to the frequencies
indicated in the graphs, and the input power was stepped and
data recorded in 1 dB increments.
Information and details regarding how to use the evaluation
software for data capture can be found in the CN0187
Evaluation Software Readme file.
Information regarding the SDP board can be found in the
SDP User Guide.
LEARN MORE
CN0187 Design Support Package:
http://www.analog.com/CN0187-DesignSupport
SDP User Guide
Ardizzoni, John. A Practical Guide to High-Speed Printed-Circuit-
Board Layout, Analog Dialogue 39-09, September 2005.
CN-0150 Circuit Note, Software-Calibrated, 1 MHz to 8 GHz,
70 dB RF Power Measurement System Using the AD8318
Logarithmic Detector, Analog Devices.
MT-031 Tutorial, Grounding Data Converters and Solving the
Mystery of “AGND” and “DGND”, Analog Devices.
MT-073 Tutorial, High Speed Variable Gain Amplifiers (VGAs),
Analog Devices.
MT-077 Tutorial, Log Amp Basics, Analog Devices.
MT-078 Tutorial, High Speed Log Amps, Analog Devices.
MT-081 Tutorial, RMS-to-DC Converters, Analog Devices.
MT-101 Tutorial, Decoupling Techniques, Analog Devices.
Whitlow, Dana. Design and Operation of Automatic Gain
Control Loops for Receivers in Modern Communications
Systems. Chapter 8. Analog Devices Wireless Seminar. 2006.
Data Sheets and Evaluation Boards
CN-0187 Circuit Evaluation Board (EVAL-CN0187-SDPZ)
System Demonstration Platform (EVAL-SDP-CB1Z)
ADL5502 Data Sheet
ADL5502 Evaluation Board
AD7266 Data Sheet
AD7266 Evaluation Board
ADA4891 Data Sheet
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