Wideband RF development platform records and plays back

Are you involved in the design of software-defined radios or high-speed RF systems? If so, check out this product from board maker Pentek Inc. As a vendor of VME bus board-level technology, it's unveiling the latest member of its existing RTS 2500 development platforms. These systems are for realtime wideband data acquisition, signal processing and recording.

Dubbed the RTS 2502, this latest board adds playback capability to the family, using the same data-capture front-end as the company's forerunner RTS 2501. The 2502 adds no less than four digital-to-analog converter (DAC) channels, with two up-converters for playback. The board uses Texas Instruments' DAC5686 DACs.

Out-of-the box deployment
Right out of the box, the RTS 2502 comes pre-configured as a data recording system. It also uses a graphical user interface (GUI) so that you can rapidly deploy it as programmable development platform for transceiver applications such as military radios or commercial wireless base stations.

Instead of using simulated signals and signal analysis tools during system development of radar or communication systems, you can take an RTS 2502 into the field to capture and generate realworld signals in realtime. That lets you do direct validation of both signal-processing algorithms and system hardware.

Both recording and playback functions use an industry-standard 2Gbps Fiber Channel interface to either a RAID (redundant array of independent disks), or to JBOD (just a bunch of disks). Recording time is limited only by the size of the hard drives, and it scales to your application.

Software support
As with other members of Pentek's RTS 2500 family, the 2502 is supported by the company's SystemFlow software. Because SystemFlow software supports the entire RTS 2500 family, it ensures a consistent look-and-feel across all Pentek platforms.

SystemFlow lets you customize features, interfaces, and operations using a modular design that includes code for the data acquisition system as well as user control. API (application program interface) library functions are provided with source code so you can either modify the example code or use it as a reference for your own customized software.

SystemFlow software includes API libraries for the target board as well as user-control libraries for your host PC. Windows DLL (dynamic link library) calls are written in Visual C++. A PC host front-end can communicate over Ethernet with the royalty-free eCos realtime operating system on the G4 PowerPC target board, which executes realtime application code.

The software package also includes a data viewer, written in National Instruments LabVIEW. It shows display plots of collected data in either the time domain or frequency domain. You can use the viewer to preview data before storage or to review stored data.

Inside the RTS 2502
Let's take a closer look at the RTS 2502. Each card in a typical RTS 2502 system accepts signals through two Analog Devices AD6645 14bit analog-to-digital converter (ADC) chips running as fast as 105MHz. Signals are fed through digital down-converters to Xilinx Virtex-II FPGAs for signal processing and data handling.

The unit can send raw or processed data to the disk array at speeds up to 160MBps for recording. The RTS 2502 can also send data off-board through front-panel data port, RACE++ or Gigabit Ethernet ports.

Digital up-conversion
Two playback channels in the RTS 2502 each offer digital up-conversion. Dual 500MHz 16bit DACs produce either real or IQ (in-phase and quadrature) RF signals, drawing data from the disk array at up to 160MBps (or from other I/O, as desired). The multiple Virtex-II FPGAs provide signal processing, formatting and other data manipulation for I/O channels.

Pentek supports FPGA development with its GateFlow FPGA design kit. The kit package includes design information, software files, optimized DSP functions and development utilities. Pentek also offers GateFlow intellectual property cores that include fast Fourier transforms, wideband and narrow-band digital down-converters, and a radar pulse compressor.

Physically, the RTS 2502 occupies a single 6U-sized VME card, enabling as many as 20 units to fit into a standard cardcage. The unit is highly modular, supporting 40 input channels and 80 output channels with this configuration.

Extensibility
In addition, using the firm's Model 9190 Clock/Sync Generator, you can sync up to 80 I/O modules, each with a common clock and up to five different timing signals for synchronizing, triggering and gating functions.

An RTS 2502 base system starts at about $30,000 for hardware only. It's also priced at about $41,500 with bundled SystemFlow and GateFlow software (you can use one software suite across multiple hardware platforms). Delivery is eight to 12 weeks ARO.

- Alex Mendelsohn
eeProductCenter