Application Note

AN RFMD® APPLICATION NOTE
RFSM6575RC128A-410 Reference Design
Overview
The RFSM6575RC128A-410 reference design is a partnership between RFMD and Atmel presenting a complete 2.4GHz IEEE
802.15.4-compliant radio transceiver solution. Atmel introduces the ATmega128RFA1 as its ZigBee platform which incorporates a low power 2.4GHz radio frequency transceiver and a High Performance, Low Power AVR, 8-bit microcontroller into a single 9mmx9mmx0.9mm 64-pin QFN package. RFMD presents a world class Front End Module (FEM), the RF6575 for efficient
extended output power above 20dBm with harmonic filtering, diversity switch, and LNA.
This document briefly describes the RFSM6575RC128A reference design and how it is set up and configured for engineering
evaluation of the RF6575 FEM using Atmel's ATmega128RFA1.
Figure 1. Top and Bottom View of RFSM6575RC128A Reference Design
RF MICRO DEVICES®, RFMD®, Optimum Technology Matching®, Enabling Wireless Connectivity™, PowerStar®, POLARIS™ TOTAL RADIO™ and UltimateBlue™ are trademarks of RFMD, LLC. BLUETOOTH is a trademark owned by Bluetooth SIG, Inc., U.S.A. and licensed for use by RFMD. All other trade names, trademarks and registered trademarks are the property of their respective owners. ©2010, RF Micro Devices, Inc.
110215
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected]
1 of 10
RFSM6575RC128A-410 Reference Design
Figure 2. Layout (Top View)
110215
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected]
2 of 10
RFSM6575RC128A-410 Reference Design
Figure 3. Schematic
This schematic shows the interconnection for RFMD's 6575 PA and Atmel's ATmega128RFA1. The rest of the schematic can be
found at RFMD.com.
110215
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected]
3 of 10
RFSM6575RC128A-410 Reference Design
Evaluation and Configuration
The RFSM6575RC128A reference design is evaluated on the Sensor Terminal Board (STB). The STB is intended to serve as a
PC interface to establish a USB-based UART connection, programming interfaces, and to provide an RCB power supply using
the USB cable. Ordering information for the STB, as well as description, technical data, documentation, and drivers can be
found at http://www.dresden-elektronik.de/shop/prod75.html.
Figure 4. Sensor Terminal Board
With the RFSM6575RC128A-410 reference design powered and connected to a computer, a terminal emulator can establish
communication with the appropriate USB-based UART connection. Install the drivers that work with your operating system as
these drivers are needed to establish communication. Drivers can be obtained from http://www.dresden-elektronik.de/shop/
media/products/0714253001283937459.zip.
To installing and configure the reference design:
1.
2.
3.
4.
5.
6.
7.
8.
To control the RFSM6575RC128A that is mounted on the STB, a USB connection between the STB and a host PC is
required. Connect USB "X2" connector of the STB with a host-PC USB interface. This causes a driver installation procedure to install a basic device driver in the first run, and a serial driver on top of the basic USB STB driver in the second
run. If the STB is connected the first time, the "Found New Hardware Wizard" dialogue displays.
Disable Windows Update to search for software.
Select the path where the driver was downloaded before.
Perform both installation procedures in a similar way. After completion, the Windows Device Manager (Start>Settings>Control Panel>System>Hardware>Device Manager) displays the assigned COM port number under Ports
(COM&LPT).
Note this COM port number to configure the terminal application controlling the RCB.
(To establish a connection to the RFSM6575RC128A-410 reference design board and enable the test menu options; the
following information must be stored in the terminal emulator application. Hyperterminal was used for the purposes of
this document.) Name your file. The "connect using" field displays.
Choose the Proper COM port. For the "Bits per second" field choose 9600. For the "Data bits" field choose 8. For the "Parity" Field choose none. For the "Stop Bits" field choose "1". And lastly for the "Flow Control" field select none. The terminal
screen displays.
Press any key to establish communication with the RFSM6575RC128A reference board.
110215
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected]
4 of 10
RFSM6575RC128A-410 Reference Design
The images below display once the RFSM6575RC128A-410 board is connected properly. Images of the various menu options
that configure the reference board accordingly for transmit and receive testing are also shown. Direct additional questions to
the RFMD Wireless Connectivity Business Unit (WCBU) Application Engineering Team.
Figure 5. RFSM6575RC128A-410 Reference Design Initial Response from Terminal Emulator (Main Screen)
Transmit Test Setup
1.
2.
3.
4.
5.
6.
7.
8.
9.
Set the Channel to the channel to test. The default is Channel 20. To change the channel, enter "C" and the 2-digit channel number.
Press "Enter". The channel number on the main screen displays the current channel selected.
Set the Tx power level, the default is 3 dBm. To change the Tx power level, enter "W" and the transmit power value (in
dBm, -5 for example).
Press "Enter". The Tx power level on the main screen displays the Tx power level selected.
Toggle Antenna Diversity by entering “Y”. The default setting is disabled. Depending on which Antenna you wish to test will
determine this setting. There are four to toggle between: 1) disabled, 2) enabled: static ANT0, 3) enabled: ANT1, and 4)
enabled: dynamic. The selected setting displays on the main screen.
Toggle RFFE Control. There are two settings to toggle between: 1) enabled, and 2) disabled. This setting needs to be
enabled Now you are ready to transmit.
Enter "U" for continuous transmission on current channel.
Choose the transmission mode. There are two: "C" for CW mode, or "P" for PRBS mode. A signal on the spectrum analyzer
connected to the antenna displays. If you have a power meter connected, you should see a power level shown.
To Stop Transmission, press any key.
110215
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected]
5 of 10
RFSM6575RC128A-410 Reference Design
Transmission Test Data
Tx Data
Channel/MHz
POUT (dBm) at -30°C
POUT (dBm) at 25°C
POUT (dBm) at 85°C
Channel 11 (2405)
22
22
20.9
Channel 12 (2410)
22
21.9
20.8
Channel 13 (2415)
22
21.8
20.8
Channel 14 (2420)
21.9
21.7
20.7
Channel 15 (2425)
21.8
21.6
20.6
Channel 16 (2430)
21.7
21.4
20.4
Channel 17 (2435)
21.5
21.4
20.4
Channel 18 (2440)
21.5
21.4
20.4
Channel 19 (2445)
21.4
21.4
20.3
Channel 20 (2450)
21.3
21.3
20.3
Channel 21 (2455)
21.3
21.3
20.2
Channel 22 (2460)
21.2
21.2
20.2
Channel 23 (2465)
21.1
21.1
20.1
Channel 24 (2470)
21.0
21.0
20.1
Channel 25 (2475)
21.0
21.0
20.1
Channel 26 (2480)
21.0
21.0
20.1
Tx Harmonic Data
2nd Harmonic over Temperature
Channel/MHz
2fo (dBm/MHz) at -30°C
2fo (dBm/MHz) at 25°C
2fo (dBm/MHz) at 85°C
Channel 11 (2405)
-66
-55.3
-52.4
Channel 19 (2450)
-52.9
-50.3
-51.2
Channel 26 (2480)
-48.8
-45.6
-47.1
3rd Harmonic over Temperature
Channel/MHz
2fo (dBm/MHz) at -30°C
2fo (dBm/MHz) at 25°C
2fo (dBm/MHz) at 85°C
Channel 11 (2405)
-45.5
-51.8
-51.2
Channel 19 (2450)
-45.3
-52.1
-51.2
Channel 26 (2480)
-48.8
-53.5
-51.5
110215
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected]
6 of 10
RFSM6575RC128A-410 Reference Design
Packet Error Test Rate
This section contains a test setup diagram for Packet Error Rate Testing (PER) along with the display screens that display during PER testing.
*Everything inside this
Gray box is inside a
screen (Shielded) room.
USB
CABLE
USB
CABLE
Sensor Terminal Board
EXT0
Sensor Terminal Board
EXT0
EXT1
ANT
EXT1
ANT
Variable
Attenuator
RFSM6575RC128A
Set to TX mode
RFSM6575RC128A
Set to RX mode
Figure 6. Packet Error Rate (PER) Testing Setup
110215
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected]
7 of 10
RFSM6575RC128A-410 Reference Design
Two RFSM6575RC128A reference designs are required to perform PER testing: one set to Receive mode and another set to
Transmit on the same channel.
To set up PER testing:
1.
2.
3.
4.
5.
6.
7.
8.
9.
Establish a connection between the two RFSM6575RC128A reference designs by starting the terminal emulator application. Hyperterminal was used for the purposes of this document. To begin, Name your file. The "connect using" field displays.
Choose the proper COM port. For the "Bits per second" field choose 9600. For the "Data bits" field choose 8. For the "Parity" Field choose None. For the "Stop Bits" field choose "1". For the "Flow Control" field select none. The terminal screen
displays.
Press any key to establish communication with the RFSM6575RC128A reference board.
Configure the Receive RFSM6575RC128A. To begin, set the Channel: Press "C" and select a channel between 11 and 26.
Press “Y” to toggle Antenna Diversity to Enabled: Static ANT0.
Press “Z: to toggle RFFE control to Enabled.
Press “R” to set Operating mode to RX.
Press “S” to start test. "Receiving…” displays.
Press any key when test is completed.
Figure 7. Correctly Set Main Screen for Proper Receive Node
10. Configure the Transmit RFSM6575RC128A. To begin, set the Channel: press "C" and select a channel between 11 and
26.(the same one from step 4)
11. Press “N” to set the number of frames to be sent.
12. Enter the desired amount. For this example 1000 is used.
13. Press “A” to toggle the ACK request until "No ACK requested" displays.
14. Press “F” to toggle Frame Retry until False displays.
15. Press “M” to toggle CSMA Enabled until False displays.
16. Press “Y” to toggle Antenna Diversity until Enabled: Static ANT0 displays.
17. Press “Z” to toggle RFFE control until Enabled displays.
18. Press “T” to toggle Set Operating Mode until Tx displays.
19. Press “S” to Start Test. "Transmitting…” displays.
20. Wait until test is completed. Once the Test is complete the results display.
110215
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected]
8 of 10
RFSM6575RC128A-410 Reference Design
Figure 8. Receive Test Result
21. Go to the receive nodes terminal emulator and press the spacebar. The results of the Receive test display at the top of
the screen. This defines your PER value. For example 1000/1000 equates to a 0% PER, 900/1000 equates to a 10%
PER.
Figure 9. Correctly Set Main Screen for Proper Transmit Node
110215
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected]
9 of 10
RFSM6575RC128A-410 Reference Design
Rx Sensitivity Performance
Rx Sensitivity Data
1% (PER)
20% (PER)
Channel 11
-104.5
-105.5
Channel 19
-104.5
-105.5
Channel 26
-104.5
-105.5
The output power from the Transmit RFSM6575RC128A board should be measured separately. This power level is needed as
a baseline for calculating the attenuation level between the Transmit RFSM6575RC128A board and Receive
RFSM6575RC128A board.
If you have any additional questions please email [email protected]
110215
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or [email protected]
10 of 10