R. A. Wood Associates QuickNews

High Dynamic Range Microwave Tuner Designed and in Production

We haven't posted in a while. It's because we've been crazy busy. Our newest product, the RCT0017 WB Tuner and Quad Converter, has been under development over the past 2 years, and is now available. We've designed this from the ground up to meet state of the art high input compression point, low phase noise, fast tuning speed, wide dynamic range, and wide instantaneous bandwidth requirements. A quick overview of the specifications: Frequency Coverage: 2-18 GHz First IF’s: 2.2-3.8 GHz, 3.8-5.3 GHz, available simultaneously Second IF’s: 4 outputs at 750 MHz, 375 MHz wide, providing 1.5 GHz instantaneous bandwidth across the First IF’s Input 1 dB Compression Point: >+6 dBm Noise Figure: 21 dB Input Dynamic Range: -60 to +2 dBm Gain: 10 dB average Tuning Speed: <1 uSec Frequency Step Size: 375 MHz Phase Noise: -150 dBc/Hz @ 10-20 MHz Offset Form Factor: VME 6U 2 Slot Design Control and Status: VME A24 D32 Designed to follow an Low Noise Front End with Approximately 30 dB ENR Designed to drive 1 GHz Digitizers linearly up to +12 dBm A brief data sheet can be downloaded from this link

R. A. Wood Associates awarded contract from NSWC Crane Division

R. A. Wood Associates has been awarded a contract from Naval Surface Warfare Center (NSWC), Crane Division. The contract involves designing and delivering an automated test rack consisting of: A 40U rack with rack mount PC, work table, LCD monitor, GPIB controller cards, A state of the art Vector Network Analyzer (VNA) with 10 port extension A PXI chassis with PXI cards providing thermocouple temperature measurement, serial ports, 2 X 96 digital I/O signals A custom designed RF Load Box for testing up to eight transmitter/receiver modules, capable of providing 50 Watts of RF power Custom designed software for controlling the Load Box and the VNA equipment We are fortunate to be able to work with Viewpoint Systems on this contract. This contract was won on a competitive bid, and our solution was selected out of many other submissions. We are very excited about the opportunity to work with NSWC Crane Division!

LB RF Amplifier Modules delivered

Using our Extreme BW RF amplifiers, we designed, built, and tested 7 LB RF amplifier modules for one of our customers. Our customer's original vendor failed to deliver their amplifier products and meet the requirements. So we stepped in and helped them meet their delivery schedules. These modules were made to "drop in" to our customer's modules. These modules will be used in our customer's systems, which will be installed on board Navy vessels. A full set of test data was provided for each LB RF Amplifier Module delivered. Our automated RF test software (RFSpecTest and Painless Extraction) helped to quickly capture the test results and create the test reports.

Equalizer Designs now extended up to 18 GHz

Hello Everybody

We've enhanced our portfolio of equalizer designs with new high frequency equalizers, with low losses all the way up to 18 GHz!

We also now have a smaller package design (M02 package).

We can now offer low loss, high linearity equalizers over the following frequency bands:

5 KHz to 2.0 GHz 0.5 to 8.0 GHz 1.0 to 8.0 GHz 1.0 to 2.0 GHz 2.0 to 4.0 GHz 4.0 to 8.0 GHz 4.5 to 12.5 GHz 4.0 to 18.0 GHz 8.0 to 18.0 GHz

Electronics Support Switching Unit (ESSU) designed, built, and tested by R. A. Wood Associates

R. A. Wood Associates designed, built, tested, and delivered 2 Electronics Support Switching Units (ESSU) to one of our customers. This was another set of hardware slated to to be installed on a Navy Vessel. The ESSU was designed to be installed between the front end (Antennas, RF amplification switching, filtering) and back end (RF processing) of a complex RF/Microwave system. The purpose of the ESSU was to allow a second front end (RF Subsystem 2) to be switched into the same back end, to make use of the RF signal processing in the back end. Some of the major components in the ESSU are as follows: Wideband RF/Microwave amplifiers Our Extreme BW RF amplifier was used in this design for the low frequency, wide bandwidth RF path Equalizers and attenuators to align the RF paths Some vendor purchased equalizers were used R. A. Wood Associates equalizers were also used where vendor equalizers were not available Terminated mechanical RF switches (50 ohms) Terminated mechanical RF switches (75 ohms) HDRFI external RF interface to save RF connector space DC power conditioning FPGA card to control switches and provide Built-in-test (BIT) status LED displays for BIT and switching status Custom designed audio switching board

Extreme BW RF Amplifiers

We've taken a challenge and come out on top again! We've developed an Extreme BW RF Amplifier, providing ~22 dB gain, and high dynamic range (~36 dBm Third Order Output Intercept Point) over the frequency band of 5 KHz to 2 GHz. An integrated RF package of 1.9" L X 1.3" W X 0.4" H was developed for the Extreme BW RF Amplifier and also included: DC filter to suppress power supply ripple and noise An input Equalizer where you can specify the full band slope desired An output Resistive Power Divider for providing 2 equal RF outputs The input Equalizer and output Power Divider can be "zeroed out" if not needed. The input Equalizer can be used to compensate for the amplifier slope and/or passive loss slopes. We can provide a variety of RF slopes in the input Equalizer. More information is available from our Extreme BW RF Amplifier page. Let us know if you are interested in this product line! Bob Wood.

JBU RF Plate Assemblies designed and delivered for Naval Application

R. A. Wood Associates designed, built and tested and delivered 2 "JBU RF PLate" Assemblies. These RF assemblies were used to provide wideband gain, equalization, and Built-in-test (BIT) injection between two very long RF cable runs (between an Antenna Assembly and below decks receivers). The gain and equalization was needed to preserve the RF path noise figure and dynamic range performance through the long cable run. The exciting part for us is that this design will actually be deployed on a US Naval vessel. This is our first of several LRU's that were designed to be used on a US Naval vessel.

New "Equalizers on Demand" RF products available

Greetings! We've been very busy working on creating a new series of RF/microwave products: "Equalizers on Demand". "Equalizers on Demand" are wideband, low loss frequency equalizers made to provide a positive gain slope from the lower frequency to the upper frequency. These equalizers are designed to flatten out slope caused by long cables or other passive losses, or amplifier negative gain slopes. We have developed a wide series of equalizers with various slopes covering the following frequency bands:

• 5 KHz to 2.0 GHz
• 0.5 to 8.0 GHz
• 1.0 to 8.0 GHz
• 1.0 to 2.0 GHz
• 2.0 to 4.0 GHz
• 4.0 to 8.0 GHz
• 4.5 to 12.5 GHz

Equalizers are very important to help your system obtain the best dynamic range performance. You can use them to flatten out a negative gain slope to reduce gain tolerances/differences before going into high dynamic range amplifiers.

We're hoping this series of products create a new paradigm in RF performance. We can provide these very quickly to help correct slope in an RF path, "Equalizers on Demand" can trim RF path slopes almost as easily as attenuators can be used to adjust nominal gains.

These products were developed internally to fill a void in the RF industry. It's very difficult to quickly order a fixed slope equalizer to correct an excessive sloped RF path without waiting 10-12 weeks for delivery. Our losses at the high frequency are the lowest available in the industry. We've searched far and wide to find products with the characteristics of our products, but could not find vendors to supply them. So we bit the bullet (many bullets) and worked on these designs ourselves.

We've worked very hard to make these products easily producible. We can deliver these very quickly (typically 2-4 weeks). If you pre-order an equalizer in a certain frequency band, and then let us know what slope you need, we can most likely incorporate the slope and deliver a tested equalizer within 1-2 weeks.

For more information for the current products and designs available, please visit our "Equalizers on Demand" product page.

We hope we can help improve your RF/Microwave system performance with these products! Bob Wood

RF Receiver Simulator Delivered!

Hello Everybody

We just delivered our latest product: a multi-channel RF/Microwave Receiver Simulator. This device simulates the RF front end of an ESM (Electronic Support Measures) system. The simulator matched the noise figure, gain and dynamic range of the RF front end. The simulator contained 9 channels of RF bands covering from 10 MHz all the way up to 40 GHz.

Some pictures of the RF Receiver Simulator are shown below. The RF Receiver Simulator is a 3U rack-mounted assembly mounted in a protective roll-away cart for ease of transportability.

EW Receiver Simulator designed, built, tested, and delivered

'We just delivered an EW Receiver Simulator to one of our customers. The simulator provided the simulated RF and microwave front end performance of an EW (Early Warning) Receiver subsystem. Our simulator allows the EW Receiver/Processor to be evaluated without requiring the actual front end system. The simulator was designed to match the system front end noise figure, gain, and dynamic range. This also represents a new modular and mechanical design for us.

A block diagram of one channel of the EW Receiver Simulator is shown below:

New Integrated RF Test Rack Designed and Delivered

On September 15 2006, R. A. Wood Associates delivered the first two of 15 complete Integrated RF Test Racks. The Integrated RF Test Rack provided a complete solution for complete automated testing of 7 RF/Digital modules. All equipment was controlled through GPIB interfaces. All automated test software was written in National Instruments LabVIEW by R. A. Wood Associates. RFSpecTest was used in "script" mode to perform most of the RF measurements. The rack consisted of: 2 Signal Generators (one for RF signals, one for LO signals) 1 Spectrum Analyzer (for measuring RF signal amplitudes and frequencies) 1 Multimeter (for monitoring resistances and voltages at various points on the modules) 3 Power Supplies (for providing DC power to the modules under test) A rack mount PC with GPIB and Digital I/O cards, loaded with software for controlling test equipment and reporting test results A rack mount interruptible power supply (UPS) R. A. Wood Associates Automated RF Test Fixture Laser Bar Code Reader (for reading and automatic entry of module serial numbers) A 19" Flat Panel Display (mounted on movable monitor arm) Keyboard and Mouse in a slide-out ergonomic tray The full rack was designed to be a comfortable testing environment, as well as easy to maintain. Equipment is easy to remove if needed with minimal interference to other equipment. More information about the Integrated RF Test Rack is available from this link.

New Computer Automated RF Test Station developed and delivered

We designed and developed a Computer Automated RF Test Station for one of our customers. The Computer Automated RF Test Station is capable of testing 7 different RF and RF/digital modules, but is flexible enough to test many possible RF modules. The Test Stations were built and tested at R. A. Wood Associates. Computer automated test software was also developed to test the 7 different modules using LabVIEW. RFSpecTest was used in a "scripted" mode to perform all RF tests. More information about the Computer Automated RF Test Station is available at this link.

New RF Receiver Simulator Delivered

We delivered a wideband RF/microwave Receiver Simulator to one of our clients on March 1. The simulator was designed to simulate the front end of an RF/Microwave system. Frequency coverage went from HF to SHF Ka Band. The simulator was required to have very low noise figures and very high intercept points/compression points. The unit was delivered in 6 months after order. More information is available at this link location.

R. A. Wood Associates at MTT Symposium

R. A. Wood Associates Demonstrated Computer Automated RF Test Software Suite at NI Week Aug 13-16, 2002 in Austin, Texas:

Upgrade and Repair Services

Upgrade and Repair Services

• One of our clients had received some RF modules that were functionally working, but the performance was not meeting system performance requirements. We analyzed the modules, determined the changes needed to meet system performance requirements, and upgraded the RF modules for our customer. Some of the highlights of this effort:
  • New RF components were specified, sent out for quotes, and purchased from vendors
  • Improved 1 dB compression points
  • Reduced noise power levels
  • Improved P-P flatness
  • Automated RF test software was developed to perform final acceptance tests
  • Acceptance test reports were created and delivered to the customer for each upgraded RF module
  • Some of the modules were RF components interconnected with coaxial RF cables
  • Some of the modules were surface mount components on microstrip medium
  • The system performance was greatly enhanced by these upgraded RF modules

MetalTest Systems available

We have developed a computer automated Metal Tester for testing metals using thermo-electric measurements from an Acromag meter, a PC A/D converter board, and LabVIEW software. For more information, go to this page.

Filter Design Study

Filter Design Study

• We helped a customer analyze a filter specification and provide a filter design that would be producible and come as close to the filter specification as possible. The end result was that the filter requirements were not fully realizable. This enabled the customer to revise their design approach so that a more realizable filter could be utilized, thereby preventing them from going forward with a system design that was not feasible

Computer Automated Test System for LDMOS Wireless RF Power Amplifiers

Computer Automated Test System for LDMOS Wireless RF Power Amplifiers

• We provided an automated RF Test System to provide computer automated testing of LDMOS RF Power Amplifiers. The amplifiers are used in base stations for AMPS, PCS, UMTS systems. Software was developed using National Instruments LabVIEW
• RF Measurements provided at several Output Power Levels
  • Gain
  • Gain Compression (servoed to X dB gain compression)
  • Output Power (servoed to a specified power)
  • Intermodulation Products (IMD)
  • Adjacent Channel Power (ACP)
  • Return Loss
• DC Measurements included:
  • IDQ Servo (Adjust Vgg to achieve desired Idd current)
  • Idd measurement at RF Output Power
  • Ronq
  • Ronh
  • Gmq
  • Gmh
• Other Measurements
  • Efficiency
  • Power Added Efficiency (PAE)
• For an overview presentation of the LDMOS Automated Test System:
  • 3.8 MB pdf file, good for printing
  • 1 MB pdf file, good for screen viewing

Satellite Communication Phased Array Solid State Transmitter Design

Satellite Communication Phased Array Solid State Transmitter Design

• Spreadsheet modeling of RF signal paths and RF path parameters
• Developed specifications for RF components
• Performed requirements analysis and specification flow down
• Developed a "B2 Level" specification for the microwave assembly

Cable TV System Model to Predict Linear and Nonlinear Performance from Headend to the Home

Cable TV System Model to Predict Linear and Nonlinear Performance from Headend to the Home

• We developed a CATV system model to predict performance from the CATV Headend to the Home
• Performance predictions included:
  • Carrier to Noise (C/N)
  • Composite Triple Beat (CTB)
  • Composite Second Order High (CSOhigh)
  • Composite Second Order Low (CSOlow)
  • Amplitude Levels vs Frequency
  • Slope
  • Channel Plans Analyzed:
    • 79 Channel
    • 95 Channel
    • 112 Channel
    • 125 Channel
  • Other Parameters...
  • An example spreadsheet printout (Adobe Acrobat pdf format) is shown here, showing 6 cable spans and amplifiers
• Individual Components and their associated parameters were created and added to a component database. The database tracked over 900 RF component parameter fields for various components used in the cable TV industry. The initial database contained over 800 components, with capability of adding thousands more components. Data could be imported into the database from files created by other programs (S2P files, for example).

MetalTest Software

MetalTest Software

A software program was developed using LabVIEW, a graphical programming language from National Instruments. The program runs on a PC and is connected to an Acromag Metal Tester using a PC Data Acquisition board. The program compares the readings gathered from the Metal Tester to readings in a database for various alloys. The program then gave a readout of what metal alloy most closely coincided with the metal being tested. The program also provided probability levels (T-Test) to show confidences against the various other possible alloys in the database. The MetalTest System is currently being used to recycle aircraft engine machining scrap and is helping the company earn hundreds of thousands of dollars in metal reclamation sales.

Click here for more information!

EW System Analysis and Support

EW System Analysis and Support

• We helped a customer with system design, analysis and support for a naval surface ship EW system over a 3 1/2 year period. Some of the key points of this effort:
  • Developed specifications for EW subsystems, WRA's, SRA's, and RF components
  • Developed analysis programs to predict system performance and specify from subsystems down to components
  • Helped investigate new technologies for various subsystems, such as RF delay lines, RF channelizers, etc.
  • Attended vendor design reviews and meetings to support the customer

IF Receiver/Digitizer

Engineering Consulting Examples: IF Receiver/Digitizer

Software was developed to retrieve the binary data from a IF Receiver/Digitizer board. The board design utilized a 10 MHz A/D converter to sample the IF signal. A Logic Analyzer attached to the board captured the digital data from the IF Receiver/Digitizer board. The computer used an IEEE-488 interface to connect to the Logic Analyzer and retrieve the values. After the binary data was retrieved, converted, and stored in an array, the data could be graphed and analyzed. The arrays were converted to a series of voltage values of the incoming signal. The voltages were plotted and then recorded. The data was then used in signal frequency and noise analysis. The Fast Fourier Tranform was used to determine the spectral content of the sampled signals. The FFT of the digital signal could then be compared to the Power Spectrum Analyzer data of the analog signal. The software was developed using National Instruments LabVIEW graphical programming language. The measured data could be stored to a data file to record that particular test.

• Click here to see display panel showing A/D Noise Floor Measurement
• Click here to see display panel showing A/D Measurement of 4 MHz Signal
• Click here to see display panel showing A/D Measurement of 17 MHz Signal

Cryogenic Cooled RF Amplifier Development for PCS Application

Cryogenic Cooled RF Amplifier Development for PCS Application

• We helped a company involved in Cryogenic packaging to design, verify and test a cryogenic cooled LNA package. We used LabVIEW software to develop a complete computer automated test station, providing the following measurements controlled by LabVIEW via GPIB interfaces:
  • Full 2-Port S-Parameters
  • Noise Figure vs. Frequency
  • 1 dB Output Compression Point vs Frequency
  • Two Tone Third Order Output Intercept Point vs Frequency
• The test setup was designed so that a lot of detailed testing could be completed in a very short time (while the device was in a vacuum and being cooled with liquid Nitrogen. The test equipment being controlled included:
  • HP Network Analyzer
  • HP Noise Figure Meter
  • HP Power Meter
  • HP Signal Generator
  • HP Spectrum Analyzer
• All measured data was stored electronically in electronic format for importing into spreadsheet programs for further analysis and plotting of results.....

High Speed Synthesizer for Medical Monitoring Equipment

High Speed Synthesizer for Medical Monitoring Equipment

The figure above is a simplified block diagram of a high speed synthesizer developed by R. A. Wood Associates for a medical application. Some of the preliminary specifications are shown below:

• Output RF Power:
  • The output RF power in to 50 ohm load shall be 3 Watts minimum
• Output VSWR
  • 1.7:1, 50 Ohm reference impedance.
• Frequency Source Requirements
  • The RF source shall provide 2 selectable frequencies (Frequency 1 and Frequency 2). The frequencies are selected based on the logic level applied to the Freq Change Strobe. When the Freq Change Strobe is logic 0, the output frequency shall be at Frequency 1. When the Freq Change Strobe is Logic 1, the output frequency shall be at Frequency 2.
• Frequency Range
  • The output frequency range shall be 80 to 120 MHz.
• Frequency Resolution
  • The frequency resolution of the source shall be less than 1 KHz
• Spurious (In-band)
  • The maximum level of spurious signals within the frequency range of 60 MHz to 160 MHz shall be -30 dBc relative to the RF output signal level.
• Harmonics and out of Band Spurious
  • The maximum level of harmonics and spurious signals outside the frequency range of 60 MHz to 160 MHz shall be -20 dBc.
• Digital Interface:
  • Serial Interface, 2 wire, Clock and Serial Data
• Power Level Control
  • Analog Input for Power Control: 0 to 10 Volts, approximately linear, to adjust RF power from 1 to 3 Watt
• Frequency Switching Time:
  • Less than 5 uSec (actual performance is less than 10 nSec)

RF Wireless Link for 915 MHz ISM Band

RF Wireless Link for 915 MHz ISM Band

• We provided a quick turnaround prototype design for a customer. The project involved designing a wireless link for sending and receiving digital data. The transmitter used FSK modulation at 915 MHz to send the digital information. The transmit power levels were restricted to less than 1 mW. The receiver provided front end filtering, low noise amplification, and demodulation of the FSK signals to digital information. Most of the components used were RF integrated circuits from RF Micro-Devices. The link was field tested also.

Software Controlled Laser Power Meter Interface

Software Controlled Laser Power Meter Interface

• Software was developed to provide a computer-controlled interface to a Universal Radiometer. The Universal Radiometer is a piece of test equipment used to measure laser power. The device was controlled by a PC serial port. The software was developed using National Instruments LabVIEW graphical programming language.
• All instrument controls are sent from the screen display through the PC serial port to the test equipment.
• Data from the test equipment is sent via the PC serial port to the computer and analyzed and displayed on the screen display.
• Measured data can be stored to an external file in Microsoft Excel or other spreadsheet compatible format.
• Measurement statistics are calculated and displayed in real time

RF System Design for F-22 Electronic Warfare (EW) System

RF System Design for F-22 Electronic Warfare (EW) System

• RF System Performance Predictions and Specification Development
• Develop RF system analysis models to specify and predict RF system performance

Noise Figure Computer Automated Test

Noise Figure Computer Automated Test

• The Need:
  • A customer was using an existing computer automated test software to provide noise figure measurements for RF amplifiers. The program was written in HP BASIC, and the software was run on an older HP computer. The software was antiquated and not user-friendly, the computer was aging and unreliable (used 5 1/4 inch floppies, etc). The test setup was limited to about 750 MHz in frequency coverage.
  • The amplifiers were used for CATV distribution amplifiers, and the test setup was used by Incoming Inspection and Test to verify specification compliance.
  • The Customer wanted to upgrade the software to HT BASIC, replace the computer with a newer PC compatible computer, provide a better, more user-friendly interface, allow different devices to be tested to different specifications, and increase the measurement capability to provide accurate measurements up to 1000 MHz.
• The Solution:
  • R. A. Wood Associates transferred the existing software over to HT BASIC, which was then developed on a PC compatible computer. The software was completely re-written to provide a menu-based test setup, where the user could select parameters for calibration, test, and set up specification limits. Once the test parameters were set up, the test person could just insert the devices into a "quick connect" fixture and push the "TEST" button for quick verification.
  • A user-friendly test interface was designed and implemented.
  • The test procedure was revised using improved test and calibration techniques to provide accurate noise figure and gain measurements for frequencies up to 1500 MHz.
• Other Points to Make:
  • The software was developed at R. A. Wood Associates, and installed and verified at the customer's location.
  • User-defined test and calibration frequencies allowed the operator to greatly reduce test time
    • which helped save money for the customer.
  • The software was designed to be user-friendly:
    • A menu based structure was designed.
    • New test parameters could be easily be added.
    • Press "RETURN" for default parameters saved re-typing current parameters.
    • The software was structured for minimal maintenance and easy upgrades.
  • A complete user documentation package was provided to the customer for training purposes.
  • The test setup used HPIB interfacing and HP 8970A Noise Figure Meter.
  • The setup was designed to test devices in a 75-Ohm environment.
  • For the entire effort, we kept the customer's needs in mind as a primary objective.

HP BASIC Software to Provide Test Interface to Micro-controller

HP BASIC Software to Provide Test Interface to Micro-controller

HT BASIC Program for controlling an on-board micro-controller through a PC serial port interface. This was to be used in an automated test environment.

Subcontract Specification Development

Subcontract Specification Development

A commercial manufacturer needed to develop a subcontract specification for an integrated RF assembly which they wanted to send out for quotations, and subcontract the design and development services. R. A. Wood Associates analyzed the requirements for the device based on its "system" application, and developed a 25 page specification for the device. All this occurred to meet a rush deadline in about 3 weeks time. More info to be provided...

Wireless Components Research

Wireless Components Research

Provide research and quotes for wireless components including low noise RF amplifiers, ceramic filters, base station duplexers in the cellular frequency bands.