National Instruments’ PXIe-5665 14-GHz VSA

National Instruments’ PXIe-5665 14-GHz VSA

To find out how National Instruments developed its 2011 Product of the Year — the PXIe-5665 14-GHz three-stage RF vector signal analyzer — we held an e-mail interview with Raajit Lall, NI’s Product Marketing Manager for RF and Wireless Test, who is responsible for the product. Here’s how he described the product’s origin.

Electronic Products: When was it decided to try to design the product?

Lall: At National Instrument we build upon a lot of technologies, starting from the 25+ years of expertise in LabVIEW to 15+ years of experience in PXI. We announced our 6.6 GHz suite of RF products (NI 5663e and NI 5673e) in 2008 that were well received. After the success of the 6.6 GHz products, we wanted to prove that we could also build microwave instruments with world class performance in the PXI platform. That being said, our typical development time ranges from 1.5 to 3 years on RF products.

Electronic Products: Who came up with the idea for it?

Lall: The vision of our company is often driven by our CEO, Dr. James Truchard. While there aren’t any particular individuals who came up with the idea, product marketing, sales, and R&D worked very closely to come up with the ideas and design of this product.

Electronic Products: What was the development timeline, from first concept to introduction?

Lall: Since many technologies such as PXI, FPGAs, and software get reused, it is difficult to say when the concept was first started. However, the idea for a high-performance RF product was conceived 2.5 years before the product was released in 2011.

Electronic Products: What were the critical milestones in the design?

Lall: Fitting high-performance RF components in the small form factor of PXI is always challenging and was definitely a key milestone. Some of the others were:

Phase noise requirements: The NI PXIe-5653 synthesizer module (part of the 5665) is a key component. Designing oscillators with the low jitter requirements of the 5665 in such a small space is always a challenge. Given that the 5665 is a three-stage superhet architecture, all three local oscillators on the 5653 contribute to the overall phase noise specification of the 5665. Figuring out the design, testing, and manufacturing of the 5653 was key to this project.Calibration: The NI design team came up with innovative group-delay calibration techniques applied to the entire 50-MHz bandwidth of the instrument. This provides world class EVM numbers for wide-band RF standards such as LTE and WLAN.

Electronic Products: Were there any surprises in the course of design? Challenges? How were they dealt with?

Lall: In addition to the challenges discussed above, heat dissipation in the small form factor of a PXI chassis was particularly challenging. The design team came up with innovative shielding and heat dissipation techniques to account for the heat generated by the product. The calibration over varieties of temperatures also helps keep the instrument accurate over a wide temperature range.

Electronic Products: What was the market reaction to the introduction?

Lall: The 5665 was extremely well received by the market. It has the R&D grade quality required for characterization and validation labs yet has 10X the speed of boxed instruments, making it ideal for production opportunities as well. We have many customers, such as ST Ericsson, who are realizing the cost, speed, and accuracy benefits of the 5665.

Electronic Products: What happens next?

Lall: Given the success of the 5665, NI will continue on high-performance analyzers. The other key benefit of the PXI platform is the use of open FPGAs. We demonstrated the use of open FPGAs with the NI 5665 + NI FlexRIO where customers can get up to 80X improvements in speed by moving FFTs into the FPGA instead of on a OS based instrument. NI will continue providing IP and instruments with an open programmable FPGA giving customers the flexibility to completely customer their high-performance instruments.

Richard Comerford