
The recent expansion of wireless applications to millimeter wave (mmWave) frequencies for 5G networks, satellite communications and other systems has necessitated upgrades in test instrumentation, cables and other accessories for many labs. Test equipment at the 40 GHz range is both expensive and highly sensitive, which means unexpected accidents and unexpected costs are common.
A 40 GHz network analyzer runs well into the six-figure range, and the 2.92 mm and 2.4 mm connectors needed to support high frequency operation are easy to damage and expensive to replace. Instrument manufacturers typically design high-frequency vector network analyzers (VNAs) with 2.92 mm or 2.4 mm rugged-male connectors, also known as network measurement divivision or “NMD” connectors, to reduce the risk of damage from routine use. But if you’ve worked with this equipment in a real-world lab environment, you know accidents still happen. You may also know that a repair for a damaged RF port might cost up to $5K, not counting lost productivity due to downtime.
Fortunately, there’s an easy way to protect high-frequency VNA ports that comes with some added benefits. Fitting your VNA ports with NMD adapters protects the instrument from potential damage caused by improper cable connection/disconnection. If someone misaligns the connectors or uses a cable with a broken connector, it’s a lot easier and less costly to replace the adapter than to send your VNA out for repair.
In addition to protecting your VNA ports, NMD adapters are available in 2.92 or 2.4 mm NMD-female connectors on one end, and standard 2.92 or 2.4 mm standard connectors on the other. These devices give you the flexibility to use standard test cables in your inventory instead of stocking up on specialized VNA cables, which can be quite pricey.

Mini-Circuits offers NMD adapters for 2.92 mm and 2.4 mm connectors with, NMD-to-NMD and NMD-to-standard configurations with various gender combinations to support different requirements as shown below.
Model | connector # 1 | connector # 2 | Frequency |
KF-24MNMD+ | 2.92mm- Female | 2.4mm NMD – Male | DC-40 GHz |
KFNMD-24MNMD+ | 2.92mm NMD-Female | 2.4mm NMD – Male | DC-40 GHz |
KFNMD-KMNMD+ | 2.92mm NMD-Female | 2.92mm NMD -Male | DC-40 GHz |
KFNMD-KM+ | 2.92mm NMD-Female | 2.92mm – Male | DC-40 GHz |
KM-24MNMD+ | 2.92mm-Male | 2.4mm NMD – Male | DC-40 GHz |
KMNMD-24MNMD+ | 2.92mm NMD-Male | 2.4mm NMD – Male | DC-40 GHz |
The takeaways are clear. These adapters can help any customer working with high-end test instrumentation:
- Protect VNA ports
- Avoid equipment downtime and costly repairs due to connector damage
- Gain flexibility to use standard test cables in your inventory
Browse our full selection of adapters, including NMD adapters on the Mini-Circuits website
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