Chris Shelly, Samtec’s RF/SI Modeling Engineer, walks us through a live 12G-SDI transmission line demonstration at NAB 2019. This demo showcases the signal processing capabilities of the Phabrix® QX UHDTV 12G-SDI generator/analyzer and the transmission of those signals through several other Samtec 75 ohm PCB connectors and cable assemblies.
The Phabrix QX is generating a 12G-SDI signal, through two Samtec right-angle BNC connectors, and back into the Phabrix QX for analysis. We get a good look at the resulting eye pattern for this signal, the test pattern being generated, and the test pattern being received.
12G-SDI Transmission Lines
To emphasize the performance of the Samtec HDBNC, DIN7A, and BNC7T series of products, Chris then routes the 12G SDI signal through a daisy chain of 12 connector pairs, including ten right angle connector pairs, two pairs from each of these series. As expected there is some drop in the peak voltage for the eye pattern as well as some increased jitter, but it’s still wide-open, and the received test pattern is shown to be unaffected.
Chris developed this demonstration to show the quality of the Samtec 12G-SDI RF connectors, but not thinking it was real-world application. Who would route signals through 12 connectors? We’ve since learned from customers that this type of set-up is not-so-rare and therefore this isn’t a merely hypothetical demonstration.
The demonstration highlights the custom launch design that successfully allows even the more challenging right-angle connector configurations to perform at this high level. With PCB terminated RF connectors, the design of the launch (the transition from the connector to the trace on the board) is critical to the ultimate performance of the RF connection. Samtec offers custom launch design services to assure the best possible performance of our RF PCB connectors when terminated to our customers’ specific PCB stack and construction.
Auto-Placeable RA BNC Connector
While maintaining 12G-SDI performance, Samtec experts modified the weight of the low-profile, right-angle BNC connector to keep it balanced during automated placement without fixturing. The top surface area was also increased for a machine vacuum seal, making the use of industry standard pick-and-place machines possible.
By the way, one of the connector sets in this demo is the BNC7T-BM1D, Samtec’s new low profile, right-angle 75 Ω BNC connector. This 12G-SDI product, exclusive to Samtec, is engineered for pick-and-place assembly.
To learn more about 12G-SDI connectors and Samtec’s optimized launch capabilities, please contact the RF Technical Group. These services are available to optimize the performance of any of our BNC, HDBNC, DIN or other 75 Ω series of PCB terminated connectors for your particular PCB stack up, regardless of materials and thickness.
BTW, it’s fun making a video with Chris Shelly.