Richardson RFPD RadioCarbon RFPD-RC-4450-50 User manual

Available exclusively from Richardson RFPD - 800-737-6937 (U.S. & Canada) - 630-208-2700 (International)
Or visit www.richardsonrfpd.com. See important product notice on last page of this document.
Internal Richardson Document #
RFPD-RC-4450-50 QSG
Origination Date:07/2022
Rev C
Date: 11/2022
Page 0
© 2011 Richardson RFPD
RFPD-RC-4450-50 4.4-5 GHz, 2W Linear
Front-End Design Accelerator
Quick Start Guide

RFPD-RC-4450-50 Design Accelerator –Quick Start Guide
Available exclusively from Richardson RFPD - 800-737-6937 (U.S. & Canada) - 630-208-2700 (International)
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Internal Richardson Document #
RFPD-RC-4450-50 QSG
Origination Date:07/2022
Rev C
Date: 11/2022
Page 1
© 2011 Richardson RFPD

RFPD-RC-4450-50 Design Accelerator –Quick Start Guide
Available exclusively from Richardson RFPD - 800-737-6937 (U.S. & Canada) - 630-208-2700 (International)
Or visit www.richardsonrfpd.com. See important product notice on last page of this document.
Internal Richardson Document #
RFPD-RC-4450-50 QSG
Origination Date:07/2022
Rev C
Date: 11/2022
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© 2011 Richardson RFPD
1Table of Contents
2 Introduction - About This Document...........................................................................................................4
3 Additional Heatsink .....................................................................................................................................5
4 RFPD-RC-4450-50 Module –Standalone Mode ..........................................................................................7
5 RF Bench Setup –Standalone Transmit .......................................................................................................9
6 Hardware Setup –Standalone Transmit......................................................................................................9
6.1 DC Power Supply Connection....................................................................................................................10
6.2 Digital/Control - USB/TTL Cable Connection .............................................................................................10
6.3 RF Port Connections ..................................................................................................................................11
7 Software Setup –Standalone Transmit.....................................................................................................12
7.1 Launch RadioCarbon Software App...........................................................................................................12
oOpen the App for the RFPD-RC-4450-50 Frontend module by clicking on the icon ( ...............................12
7.2 Biasing the RadioCarbon PA ......................................................................................................................14
7.3 Turn RF signal ON ......................................................................................................................................17
7.4 Transmitter Turn OFF Sequence................................................................................................................17
8 Hardware Setup –Receiver Operation......................................................................................................18
8.1 Software Setup –Receiver Operation .......................................................................................................19
8.2 Turn Receiver OFF......................................................................................................................................21
List of Figures
Figure 1: RFPD-RC-4450-50 Simplified Block Diagram............................................................................................ 4
Figure 2: Additional Heatsink with Thermal Tape and 4 Screws for Additional Dissipation .................................. 5
Figure 3: Heatsink Alignment.................................................................................................................................. 6
Figure 4: Tighten Screws......................................................................................................................................... 6
Figure 5: Final Assembly ......................................................................................................................................... 7
Figure 6: RFPD-RC-4450-50 RF Frontend Module with Input/Output Interfaces. ................................................. 8
Figure 7: Suggested Configuration for RFPD-RC-4450-50 Transmit Evaluation. .................................................... 9
Figure 8: DC Voltage VIN connection.................................................................................................................... 10
Figure 9: USB to TTL/UART cable .......................................................................................................................... 11
Figure 10: Serial cable connection to J15 ............................................................................................................. 11
Figure 11: Icon....................................................................................................................................................... 12

RFPD-RC-4450-50 Design Accelerator –Quick Start Guide
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Figure 12: Main Screen ......................................................................................................................................... 13
Figure 13: COM port Highlighted.......................................................................................................................... 13
Figure 14: Auto Refresh Box Checked................................................................................................................... 14
Figure 15: Main Screen –Setting PA Bias ............................................................................................................. 15
Figure 16: PA Bias “Quick View” ........................................................................................................................... 16
Figure 17: PA Power-Down................................................................................................................................... 17
Figure 18: Idq Verification..................................................................................................................................... 18
Figure 19: Receiver Test bench Setup................................................................................................................... 19
Figure 20: Main Window - Frontend..................................................................................................................... 20
List of Tables
Table 1: PA Bias Settings for Class AB operation.................................................................................................. 15

RFPD-RC-4450-50 Design Accelerator –Quick Start Guide
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Origination Date:07/2022
Rev C
Date: 11/2022
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2Introduction - About This Document
This document serves as a Quick Start Guide to assist users in powering up and performing bench level
testing/evaluation of the “RadioCarbon” RFPD-RC-4450-50 RF Frontend module from Richardson RFPD in
standalone mode. For the full User Guide, please refer to the USB drive included in the RFPD-RC-4450-50 kit
or from the website URL provided in the package documentation. The RFPD-RC-4450-50 Frontend module
serves as a “Design Accelerator” platform targeting RF Frontend communications applications in the 4.4 to 5
GHz frequency band. Figure 1 shows a simplified block diagram. The design was intended for lab use only and
the user may need to attach the included heatsink if they plan on using it for non-pulsed high average power
applications over an extended time.
RFPD-RC-4450-50
Pre-Driver
30dB Coupler
LNA with Bypass
MHz
50Ω
A
Circulator
LNA
1
2
Σ
Forward
Pi
10 dB
SPDT Switch
RMS Power Detect
In 90°
0°Iso
Hybrid In90°
0° Iso
Hybrid
50Ω
A
50Ω
A
A
50Ω
50Ω
A
##
Ω## nF
20dB Coupler
Forward Detect Forward
Reverse Detect
VSWR Detect
Driver
J13
Antenna
TX IN
J19
Tunable Band
Pass Filter
Pi
15 dB J1 MCX
Aux RX OutSplitter
25W PSAT HPA
25W PSAT HPA
3dB Hybrid Coupler
3dB Hybrid Coupler
RX Out
J17
Microcontroller
Power Amplifier
Current Controller
SoM Connector
JTAG/UART
ETHERNET
USB Micro-B
SD CARD
DISPLAY PORT
USB A 2.0
VIN
45 V
DC/DC 40V
J2
Figure 1: RFPD-RC-4450-50 Simplified Block Diagram

RFPD-RC-4450-50 Design Accelerator –Quick Start Guide
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Date: 11/2022
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3Additional Heatsink
When using the RFPD-RC-4450-50 for applications where the PA is likely to exceed its maximum temperature
(for example CW signals with an average input power higher than 3dBm), an additional heatsink (with thermal
tape applied) and 4 screws (Figure 2) has been included in the kit.
Figure 2: Additional Heatsink with Thermal Tape and 4 Screws for Additional Dissipation
The additional heatsink is attached directly to the RFPD-RC-4450-50. To attach, remove the blue tape from the
thermal tape, insert the 4 screws into the holes in the heatsink, and stand on end. Align PCB assembly on end
and slide close enough to heatsink to start threading screws into PCB assembly standoffs as shown in Figure 3.

RFPD-RC-4450-50 Design Accelerator –Quick Start Guide
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Date: 11/2022
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Figure 3: Heatsink Alignment
Tighten screws equally and PCB assembly will pull towards heatsink, as shown in Figure 4. Once screws are
tightened, press PCB assembly firmly down onto heatsink for proper adhesion of thermal tape.
Figure 4: Tighten Screws

RFPD-RC-4450-50 Design Accelerator –Quick Start Guide
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The final assembly should look like Figure 5.
Figure 5: Final Assembly
4RFPD-RC-4450-50 Module –Standalone Mode
In Standalone mode, the input RF Transmitter signal to the RFPD-RC-4450-50 module is sourced from a Signal
Generator and is applied at the 50 Ohm TX_IN Port (J19) as shown in the picture in Figure 6 below which shows
the actual RFPD-RC-4450-50 module with the various input/Output connections. Please note that Port J19 is a
MCX connector and there is a MCX to SMA adaptor included in the kit. The RF Output signal is delivered to the
50 Ohm RF_OUT port (J13), padded down with a 50 Ohm coaxial attenuator and measured with a
Signal/Spectrum Analyzer and Power Meter.

RFPD-RC-4450-50 Design Accelerator –Quick Start Guide
Available exclusively from Richardson RFPD - 800-737-6937 (U.S. & Canada) - 630-208-2700 (International)
Or visit www.richardsonrfpd.com. See important product notice on last page of this document.
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Rev C
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Figure 6: RFPD-RC-4450-50 RF Frontend Module with Input/Output Interfaces.
DC Power to the module is provided via an external DC Power Supply and is applied at the DC Voltage (VIN) port
J2 ( Figure 6 above). This power supply input feeds a series of on-board switching regulators that generate the
additional voltages required for the individual circuits used (including MCU and PA Bias Controller ICs) onboard
the RFPD-RC-4450-50 module.
The RFPD-RC-4450-50 module also comes with a software GUI that allows the user to control vital tasks on the
module such as ON/ Off Power sequencing of the GaN Power Amplifier devices as well as setting optimum PA
bias voltages and other key parameters both in the TX and RX paths of the system. The GUI also allows for real
time monitoring of the PA’s Drain voltages and currents, on-board Temperature Sensor readings as well as
forward power levels in the transmitter. In future reversions we will add the ability to detect reflected power
levels from the antenna.

RFPD-RC-4450-50 Design Accelerator –Quick Start Guide
Available exclusively from Richardson RFPD - 800-737-6937 (U.S. & Canada) - 630-208-2700 (International)
Or visit www.richardsonrfpd.com. See important product notice on last page of this document.
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5RF Bench Setup –Standalone Transmit
The recommended Hardware Bench setup required to properly test the RFPD-RC-4450-50 in Stand-alone
Transmit mode is shown in Figure 7.
Figure 7: Suggested Configuration for RFPD-RC-4450-50 Transmit Evaluation.
For optimum RF performance it is recommended that high quality, low loss 50 Ohm cables, adaptors and connections are
used. All RF interfaces on the RFPD-RC-4450-50 module are 50 Ohms. The RF output Attenuator needs to have at least
30dB attenuation and be able to handle 50W CW power.
6Hardware Setup –Standalone Transmit
This section of the QSG outlines the sequence of steps required for proper Hardware connections on the RFPD-
RC-4450-50 for Transmit operation.

RFPD-RC-4450-50 Design Accelerator –Quick Start Guide
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Rev C
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6.1 DC Power Supply Connection
Connect the “DC Power Jumpers (provided in the KIT) at the 2-PIN Input Voltage Terminal block (J2) as shown
in Figure 8.
Figure 8: DC Voltage VIN connection
The nominal Input DC Voltage to the RC module is 45V
* IMPORTANT: Make sure the VIN power supply meets the Minimum/Maximum Voltage and Minimum Current
capacity requirements listed below:
MIN/MAX DC Power Supply requirements:
DC Input Voltage (VIN) Range: 42V (MIN) to 47V (MAX)
Recommended (nominal) VIN: 45V DC
Set up current limit on your bench power supply to 3.5A
* IMPORTANT: Keep DC Power Supply Turned OFF at this point
6.2 Digital/Control - USB/TTL Cable Connection
Software control is provided via a RadioCarbon software APP running on a PC so a serial USB to UART/TTL cable
needs to be connected between the PC and the module as illustrated in Figure 10.
oConnect the USB to TTL/UART Serial Cable provided (Figure 9) between USB port on the PC to the 6-pin
header (J15) on the RFPD-RC-4450-50 module (Figure 10).
DC VIN
(45V)

RFPD-RC-4450-50 Design Accelerator –Quick Start Guide
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Figure 9: USB to TTL/UART cable
Figure 10: Serial cable connection to J15
6.3 RF Port Connections
oMake all 50 Ohm RF Output connections between the RFPD-RC-4450-50 module at ANT Port (J13) and the test
equipment shown in Figure 7. Make sure to insert a 30 dB (or higher) Attenuator Pad capable of handling 50W
CW, from the ANT port to the test equipment.
oMake all 50 Ohm connections between the RFPD-RC-4450-50 module and the “Input” test equipment
as shown in Figure 7. Please note that TX_IN (J19) is a MCX connector and there is a MCX to SMA adaptor
included in the kit
* IMPORTANT: Keep the RF input source (signal generator) turned OFF at this point.
USB/UART

RFPD-RC-4450-50 Design Accelerator –Quick Start Guide
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7Software Setup –Standalone Transmit
The RFPD-RC-4450-50 Software GUI that comes with the KIT handles the sequencing of the Gate and Drain
voltages on the GaN power devices in the Power Amplifier. It also provides the user the ability to establish and
monitor the Quiescent Idq currents of the driver device (CGHV1F006S) and both final stage devices
(CGHV1F025S) for optimum PA performance.
NOTE: This RFPD-RC-4450-50 Software App is designed to run on Windows based PC’s running a 64-Bit OS
7.1 Launch RadioCarbon Software App
oCopy the RadioCarbon Software App ZIP file from the USB thumb drive provided with the RFPD-RC-4450-
50 KIT to a folder and Extract files
oTurn ON the 45V power supply input to the module at VIN (J2).
oOpen the App for the RFPD-RC-4450-50 Frontend module by clicking on the icon (Figure 11) in the
RadioCarbon folder created.
Figure 11: Icon

RFPD-RC-4450-50 Design Accelerator –Quick Start Guide
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oOnce the App is launched, the following Main Window (Figure 12) appears.
Figure 12: Main Screen
oVerify that the appropriate COM port shows up and that the Attached Box is Checked as highlighted
below (Figure 13):
Figure 13: COM port Highlighted

RFPD-RC-4450-50 Design Accelerator –Quick Start Guide
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Note: If COM port is not visible, check the serial USB/TTL cable, USB driver, and hardware connection on
RFPD-RC-4450-50 at the 6-pin header J15.
oCheck the “Auto refresh” box (Figure 14) on the GUI. This provides for real-time updates to the GUI every
second.
Fig X Auto Refresh Box Checked
Figure 14: Auto Refresh Box Checked
7.2 Biasing the RadioCarbon PA
To assist the user in biasing the PA, the GUI provides 3 scroll wheels (Figure 15) which set the Gate to Source
voltage (VGS) for the Driver stage and for the Final stage devices. The resolution of the VGS Bias voltages using
the scroll wheels is as small as 1mV.

RFPD-RC-4450-50 Design Accelerator –Quick Start Guide
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Figure 15: Main Screen –Setting PA Bias
oFor class AB operation, set the VGS voltage for the Driver and the Final Stage A and B devices to
match the IDQ quiescent currents shown in Table 1.
Table 1: PA Bias Settings for Class AB operation
Device VGS IDQ
Driver Amp VGS(DRV) = -2.698 V IDS(1) = 60mA
RFPD-RC-4450-50 PA Bias Settings
Final Stage A
Final Stage B
VGS(A) = -2.932V
VGS(B) = -2.878V
IDS(A) = 150mA
IDS(B) = 150mA

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Once the VGS values are all set, the resulting IDQ current values can be observed on the main window both in
the schematic section (next to the scroll wheel) as highlighted in Figure 16 but also near the top of the GUI in
the area labeled “PA Bias Quick View”. Here the 3 VGS voltages and IDS currents are all captured together for
easy viewing.
Figure 16: PA Bias “Quick View”
Note that there may be slight differences from one RadioCarbon board to another in the exact VGS values that
corresponds to the desired IDQ values. This variation is primarily due to the device-to-device differences in
forward transconductance and threshold values, VGS(th), that will likely exist between the GaN devices used in
the PA.
PA Bias
“Quick

RFPD-RC-4450-50 Design Accelerator –Quick Start Guide
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7.3 Turn RF signal ON
Now that the PA is set to the proper quiescent bias conditions, the RF signal can be Turned ON.
oTurn ON the RF input signal applied at port J19. It’s recommended to start with a lower Input Power
level (PIN) than required and ramp PIN up until the final desired RF Output Power level (Pout) is reached
as measured at SMA port J13.
Note: The typical Gain of the RFPD-RC-4450-50 TX chain is 42 dB, so for an AVG Pout of 2W, an RF input
signal level of only -9dBm at J19 is needed.
7.4 Transmitter Turn OFF Sequence
Follow the steps outlined below to properly Turn OFF the RFPD-RC-4450-50 Transmitter and GUI:
oTURN OFF the RF input signal at the Signal Generator.
oTurn Off the PA by clicking the Red “PA Control” box on the Main GUI screen Figure 17. This action
performs the power-down sequencing of the Gate/Drain voltages.
Figure 17: PA Power-Down
Once the PA is OFF the PA Control Box is Green as seen in Figure 18.
oVerify that the Idq quiescent currents are at 0mA at the Driver and Final stage IDS fields on the GUI as
highlighted in Figure 18.

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Figure 18: Idq Verification
oTo save the VGS Bias voltage , Hit the “Store Settings”button
oExit the GUI by clicking the “close wondow” X
oTurn OFF the 45V DC Power supply input.
8Hardware Setup –Receiver Operation
To evaluate the Receiver portion of the RFPD-RC-4450-50 module, the Test Bench setup in Figure 19 is
recommended.

RFPD-RC-4450-50 Design Accelerator –Quick Start Guide
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Figure 19: Receiver Test bench Setup
As illustrated above, the specific RX test performed will determine what test equipment is required. For
example, for Noise Figure (NF) testing, it’s recommended to use a Noise Figure Analyzer with the configuration
shown in Figure 19.For S-parameter testing (S11, S21, S22, S12), a Network analyzer is required and for Third
Order Intermodulation testing (e.g., IIP3), a two-tone measurement setup using 2 signal generators at the input
and a spectrum analyzer at the output will be needed.
8.1 Software Setup –Receiver Operation
RX Testing of the RFPD-RC-4450-50 will require the user to configure the module via the SW GUI.
oMake sure all 50 Ohm cable connections between the RFPD-RC-4450-50 module and the test
equipment as shown in the RX Test Bench setup diagram in Figure 19 are secure.
oKeep RF Receiver signal source OFF at this point