Southwest Microwave RF Adapters: 2.92mm to 2.4mm and 1.85mm Selection Guide

Connecting different precision coaxial interfaces is a common challenge in microwave testing. When an RF system uses a 2.92mm (K) connector but the test instrument or cable assembly has a 2.4mm or 1.85mm (V) interface, engineers need a properly rated between-series adapter.

Southwest Microwave offers DC–40GHz precision adapters for both 2.92mm-to-2.4mm and 2.92mm-to-1.85mm connections, with female–female, female–male, male–female and male–male configurations.

This guide compares key Southwest Microwave adapter models, frequency ratings, VSWR, connector configurations and practical selection criteria for VNA measurements, microwave test equipment and RF system integration.

1. Quick Answer: Which RF Adapter Do You Need?

For a connection between a 2.92mm and 2.4mm interface, select a Southwest Microwave 101410-series adapter. For a connection between a 2.92mm and 1.85mm interface, select a 101810-series adapter.

• 2.92mm to 2.4mm: Models 101410-00SF, 101420-00SF, 101430-00SF and 101440-00SF.

• 2.92mm to 1.85mm: Models 101810-00SF, 101820-00SF, 101830-00SF and 101840-00SF.

• Maximum rated frequency: 40GHz for both between-series families.

• Key selection criteria: Interface type, connector gender, operating frequency, VSWR and mechanical compatibility.

Important: A 2.4mm interface may support 50GHz, and a 1.85mm interface may support 67GHz in other products. However, these specific Southwest Microwave between-series adapters are rated only to 40GHz. Do not assume the completed connection supports the higher frequency of one interface.

2. Southwest Microwave RF Adapter Model Comparison

The following models are listed in the manufacturer's official precision adapter catalog.

2.92mm to 2.4mm Adapters — DC to 40GHz

The 101410-00SF is a female–female inline adapter intended for high-performance connections between 2.92mm and 2.4mm interfaces. It is particularly relevant when both sides of the RF assembly require mating male connectors.

2.92mm to 1.85mm Adapters — DC to 40GHz

The 101810-00SF is a female–female adapter designed to connect 2.92mm and 1.85mm interfaces within its specified 40GHz operating range.

Gender configurations follow the manufacturer's catalog. For mixed-gender models, confirm the gender assigned to each connector interface using the individual mechanical drawing before ordering.

3. Key Specifications: 101410-00SF vs 101810-00SF

Although both products are DC–40GHz female–female adapters, their interface combinations and specified electrical performance are not identical.

Both models are designed for mode-free performance through 40GHz. Southwest Microwave specifies low insertion loss for these precision adapter products, while the exact insertion loss requirements should be confirmed from the applicable product data sheet and measurement conditions.

The 101810-00SF product specification also identifies RF leakage below -100dB.

Selection tip: Choose 101410-00SF when the required second interface is 2.4mm. Choose 101810-00SF when the second interface is 1.85mm. The specified interface must match the actual mating port; the two models are not interchangeable merely because both have a 40GHz rating.

4. How to Choose the Correct Precision RF Adapter

Step 1: Identify Both Connector Interfaces

Before selecting an adapter, identify the connector family and gender of both mating ports.

• 2.92mm (K): Common in microwave interconnections and test systems operating up to 40GHz.

• 2.4mm: Used in precision RF systems and test equipment, commonly rated up to 50GHz.

• 1.85mm (V): Used in higher-frequency microwave and millimeter-wave systems, commonly rated up to 67GHz.

Connector families can have similar external appearances, but this does not mean they should be directly mated. In particular, a 2.92mm interface should not be assumed mechanically compatible with 2.4mm or 1.85mm interfaces. Use an adapter explicitly designed for the interface transition.

For more background on SMA-related compatibility, read our SMA vs SuperSMA vs 2.92mm Connector Comparison.

Step 2: Check the Frequency of the Entire Connection

The rated operating frequency of an RF interconnection is limited by its lowest-rated component, including connectors, adapters and cables.

For example, a system may include a 67GHz-rated 1.85mm test port and a 40GHz-rated 2.92mm cable. Adding a 101810-00SF adapter does not make the full connection suitable for 67GHz operation.

For measurements above 40GHz, engineers should consider an appropriate higher-frequency cable and connector configuration, such as a dedicated 1.85mm assembly, rather than using this 40GHz between-series adapter.

Step 3: Select the Correct Gender Configuration

Southwest Microwave provides four common gender configurations for each adapter family:

• Female–Female: Suitable when the two mating cable or equipment interfaces are male.

• Female–Male: Suitable for a connection requiring one female and one male adapter interface.

• Male–Female: Provides the opposite orientation to the corresponding female–male configuration.

• Male–Male: Suitable when both mating interfaces are female.

For mixed-gender between-series adapters, verify which connector family is male and which is female before placing an order. This is particularly important when connecting expensive network analyzer or signal generator test ports.

Step 4: Evaluate VSWR and Measurement Accuracy

At microwave frequencies, impedance mismatch can cause reflected power, measurement uncertainty and ripple in the measured frequency response.

VSWR is an important indicator of impedance matching. Lower VSWR generally means reduced reflections at the adapter interface.

For the 101410-00SF, Southwest Microwave specifies maximum VSWR of 1.10:1 from DC to 27GHz and 1.15:1 from 27 to 40GHz.

For the 101810-00SF, the specified limits are 1.10:1 from DC to 18GHz and 1.15:1 from 18 to 40GHz.

When selecting adapters for calibrated measurements, also consider connector repeatability, insertion loss, calibration reference planes, mechanical wear and the combined performance of the test setup.

Step 5: Consider Connector Protection and Service Life

Precision RF adapters may also serve as replaceable connector savers between expensive test equipment and frequently changed cables.

For repeated connections, use the manufacturer's recommended mating torque, inspect center contacts before use and avoid side-loading the connector. Connector cleanliness and mechanical condition can significantly affect high-frequency measurement repeatability.

5. Typical Applications

Southwest Microwave precision RF adapters can be considered for the following applications, subject to frequency, power and mechanical requirements:

• Vector Network Analyzers (VNA): Connecting test ports to cables or devices using different precision coaxial interfaces.

• RF and Microwave Laboratories: Creating temporary interface transitions during component evaluation.

• Automatic Test Equipment (ATE): Supporting repeatable connector arrangements in production test fixtures.

• Radar and SATCOM Testing: Interconnecting microwave components within the rated frequency range.

• RF Component Characterization: Testing amplifiers, attenuators, filters and directional couplers with dissimilar connector interfaces.

If the application involves PCB-mounted RF connectors rather than inline cable or instrument adapters, refer to our Southwest Microwave 2.92mm End Launch Connector Selection Guide.

6. Related Southwest Microwave Adapter Families

For systems requiring a different interface or operating frequency, the manufacturer also offers additional precision adapter families.

These alternatives are not necessarily drop-in replacements for one another. Select according to the connector interfaces and complete RF performance requirements.

Explore the Southwest Microwave product range at DataStorageIC for additional precision connectors and microwave interconnect solutions.

7. Stock, Datasheets and RFQ

Engineers and purchasing teams can contact DataStorageIC for sourcing assistance with Southwest Microwave precision adapters, including the 101410-00SF and 101810-00SF families.

To help us identify the correct part and prepare a quotation, please provide:

• Full manufacturer part number

• Required quantity

• Connector type and gender at each interface

• Operating frequency range

• Target delivery date and destination

• Any required documentation or special test conditions

Need a Southwest Microwave RF adapter? Contact DataStorageIC to request current availability, lead time, pricing and product documentation. Availability and delivery are subject to confirmation.

8. Frequently Asked Questions

Can I connect a 2.92mm connector directly to a 2.4mm connector?

Do not assume direct mechanical compatibility. Use a specified 2.92mm-to-2.4mm adapter such as the Southwest Microwave 101410-series, selecting the appropriate connector gender and checking the manufacturer's interface requirements.

Can a 2.92mm-to-1.85mm adapter operate at 67GHz?

Not if it is one of the Southwest Microwave 101810-series adapters discussed here. These between-series products are specified through 40GHz. For 67GHz testing, use an appropriately rated interconnection throughout the measurement path.

What is the difference between 101410-00SF and 101420-00SF?

Both belong to the 2.92mm-to-2.4mm adapter family rated to 40GHz. The 101410-00SF has a female–female configuration, while 101420-00SF has a female–male configuration. Confirm connector orientation from the mechanical drawing before ordering.

Where can I obtain Southwest Microwave adapter datasheets and pricing?

Official technical specifications are available through the Southwest Microwave precision adapters catalog. For pricing, availability and sourcing support, contact DataStorageIC with the required part number and quantity.