Effects of poor connector performance on cable assemblies

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Connectors are expected to perform to the general specifications and standards of their interface series. On the other end, configurations such as receptacles, hermetics and cabling will degrade connector performance. Connectors and cable assemblies are always limited to their weakest link.

Cable connectors frequency ranges are typically spec’d at either 80% of the cable’s cutoff frequency or the connector interface standard maximum frequency (whichever is lowest). Some connector manufactures will take mechanical liberties not realizing they have gone well below the expected performance of the cable assembly.

Below is an example of a poorly performing BNC connectors effect on a cable assembly.

Bad BNCBNC’s are rated to 4 GHz, MCX (6 GHz) and RG316 (3 GHz).

Since RG316 is the weakest link, we will rate the assembly to 2.4 GHz (80%). When tested, the electrical performance is ≈ 1.314:1 @ 480 MHz.

Time domain (characterizes impedance with respect to time) measures a very high impedance section (70Ω) of considerable length located in the cable crimp area of the BNC connector.

 

 

This cable assembly has decent performance to 500 MHz where it should work well to 2.4 GHz. The customer expected a 1.35:1 @ 1.6 GHz in which it clearly failed (1.77 @ 1.48 GHz)

 

Coaxicom RFI

Left is the same cable assembly but, the BNC is replaced with a Coaxicom BNC connector of equivalent configuration. VSWR performance works beyond the specified 2.4 GHz.

 

 

 

 

 

 

Poorly designed connectors are common among many domestic and overseas manufacturers. Choosing a company that is committed to designing connectors with the performance you expect is critical in any successful RF coaxial endeavor. Coaxicom is known for their excellent performance standards and stand behind our products with exceptional quality and customer service.

 Coaxial Components Corp. is an ISO 9001:2008 / AS9100C registered manufacturing facility that ships same day from a broad inventory of microwave and RF products. www.coaxicom.com, sales@coaxicom.com, 866-COAXICOM (866-262-9426)