Pentek, Inc., with its proven track record as a pioneer in software radio innovation, introduced its Model 7152, a Quad 200 MHz, 16-bit A/D Digitizer with a 32-Channel Digital Down Converter (DDC). Configured in a PMC format, it employs a high-performance, factory-installed core for users who want to purchase a product with the critical signal processing functions already installed and functioning. It is well suited to fulfill the requirements of real-time software radio, beamforming, signal intelligence and radar systems.
“The 7152 is a welcome addition to Pentek’s FPGA (Field Programmable Gate Array) installed-core, software radio family of products,” says Rodger Hosking, vice president of Pentek. “What’s new in the 7152 is the addition of DDC gain and phase adjustments, signal summation and power meters with threshold detectors,” says Hosking. “And the range of decimation has been extended, now programmable from 16 to 8192. In addition, the factory installed IP cores save the user the task of FPGA programming. Another important feature of the 7152, retained from previous designs, is the front-panel synchronization bus that simplifies integration of larger, multi-channel systems.”
Model 7152 Installed IP Core
Pentek has been hugely successful in implementing the high-performance, pre-installed DDC IP (intellectual property) cores for Xilinx FPGAs.
By listening carefully to its customers, Pentek has equipped the Model 7152 with numerous functions essential to many communications and radar applications. Proprietary signal processing techniques provide features such as 200 MHz sampling rate DDCs, channel summation and power meters with threshold detectors.
Comparable solutions using ASICs or conventional FPGA structures would be much more expensive to implement. Multiple DDC chips and boards would be required to reproduce what is accomplished in one FPGA on a single module. Other existing DDC IP cores in the market not only use resources much less efficiently, but they also deliver limited performance.
The unique FPGA architecture combined with the high channel count and wider ranges of decimation and bandwidth makes Pentek’s Model 7152 PMC module a very high-performance, streamlined and economical solution.
Power Measurements Made Easy
The 7152 features 32 power meters that continuously measure the individual average power output of each of the 32 DDC channels. The time constant of the averaging interval for each meter is programmable up to 16K samples.
In addition, 32 threshold detectors automatically send an interrupt to the processor if the average power level of any DDC falls below or exceeds a programmable threshold. The built-in power meters and threshold detectors offload these tasks from a downstream processor, and present average power measurements for each channel in easy-to-read registers.
Power calculation and thresholding are essential functions for signal monitoring, spectral scanning, automatic gain control (AGC) loops, and beamforming and diversity receivers.
Built-In Beamforming Functions
A second set of new features makes the module ideal for beamforming applications. Each DDC channel offers programmable gain and phase adjustments, which can be applied individually or synchronously to all 32 channels. A summation block adds the complex outputs of selected DDC channels. By adjusting the phase offset and weighting of the individual channels, followed by summation, the antenna is in effect ‘steered’, rotating the azimuth angle to enhance receptivity in a particular direction.
The 7152 PMC module is also available in a variety of additional form factors: the 7652 is a PCI board, while the 7252 and 7352 are 6U and 3U Compact PCI boards, respectively.
The 7152 is supported with ReadyFlow® Board Support Packages running under Linux®, Windows® and VxWorks®. The associated model numbers are 4994A for Linux, 4995A for Windows and 4996A for VxWorks. These are complete software packages that include examples and driver interfaces for the operating system.