SMB Connector: Specs Decoded & RG316 Adaptation & Custom Services
July 2,2025
1.SMB Connector Introduction
SMB connectors are essential components in the RF industry. Their compact size, cost-effectiveness, and reliable electrical performance make them ideal for 5G communications, automotive electronics, and IoT applications.
The full name of the SMB connector is “SubMiniature version B.” It is a small RF coaxial connector that locks when you push it in.
Its main benefits are that it is compact, light, easy to use, and works very well electrically.
It works well for joining coaxial cables in radio and electronic instrument circuits that run at high frequencies. The SMB connector’s outer conductor has an inner diameter of 3mm.
It meets international standards including IEC169-10 and MIL-C-39012, which makes sure that the product can be used with other products and works reliably.
2.Main Specifications
The main specifications of the SMB connector include:
- Frequency range: Standard models generally support the DC to 4GHz band, and some high-end models can extend to 6GHz.
- Impedance: Common specifications include 50Ω and 75Ω, which are used to match different system requirements. 50Ω is commonly used in wireless communications and test equipment, while 75Ω is common in video/broadcasting and medical fields.
- Coupling mechanism: It adopts snap-on quick coupling (Push-on), which does not require rotating threads and is plug-and-play. This design makes plugging and unplugging operations simple and efficient, and is suitable for occasions where plugging and unplugging are frequent.
- Contact material: The inner contacts are mostly gold-plated to ensure low-loss and stable signal transmission.
- Installation form: SMB connectors support a variety of installation methods, including direct plug-in PCB welding, crimping cable connection, panel flange installation, etc. For example, SMB male head with nut (such as SMB-JY) can be used for panel installation.
Compared with similar connectors such as SMA, BNC, and TNC, SMB connectors have unique advantages in many aspects:
The most prominent features of the SMB connector are:
Its push-in coupling design allows for quick connection without tools, greatly simplifying the installation and maintenance process.
| Connector Type | Frequency Range | Impedance | Connection Method | Mechanical Life | Application Scenarios |
|---|---|---|---|---|---|
| SMB | 0 - 4 GHz | 50Ω / 75Ω | Push-on locking | ＞500 times | Communication equipment, IoT, medical instruments |
| SMA | 0 - 18 GHz | 50Ω | Threaded | ＞1000 times | Microwave equipment, base-station test ports |
| BNC | 0 - 4 GHz | 50Ω / 75Ω | Bayonet-type | 300 - 500 times | Test equipment, low-frequency signal transmission |
| TNC | 0 - 11 GHz | 50Ω | Threaded | ＞500 times | Anti-vibration environments, mobile communication equipment |
3.Common models and adapters
We offer a variety of SMB connector models and adapters to meet the needs of different device interfaces. For example:
Multi-port connectors: SMB Triple Female (SMB-KKK) — A three-way splitter containing three SMB female connectors for signal distribution.
Two-branch connectors: SMB male to dual female (SMB-KJK) — SMB male on one end and dual SMB female on the other end for signal branching; SMB female to dual male (SMB-JKJ) — reverse configuration for signal merging.
Panel mount type: SMB-JY (male with nut fixing) — Male with lock nut structure, suitable for panel or chassis fixing.
SMB to SMB: SMB-J/SMB-J (SMB male to male), SMB-K/SMB-K (SMB female to female) and other straight and extended connectors.
SMB to SMA/N: such as SMA/SMB-JJ (SMA male to SMB male), SMA/SMB-KK (SMA female to SMB female), SMA/SMB-JK (SMA male to SMB female), SMA/SMB-KJ and other models, as well as SMA/N-JJ, etc., are used for conversion between different interfaces.
SMB to BNC: including BNC male to SMB male, BNC male to SMB female (optionally with thread or 90 degree elbow), BNC large hexagon female to SMB male/female, BNC elbow male to SMB male/female and other combinations to meet the conversion needs of BNC and SMB interfaces in coaxial cable systems.
4.How to choose the right SMB connector?
| Key Features | Technical Parameters | Typical Application Areas | Recommended Product Models |
|---|---|---|---|
| Frequency Range | Standard SMB: 0-4GHz SSMB/Optimized: 0-12GHz SMA: 0-18GHz BNC: 0-4GHz TNC: 0-11GHz |
5G communication equipment IoT modules Consumer electronics Medical instruments Test equipment Low-frequency signal transmission Anti-vibration environments Mobile communication equipment |
SMB-KKK SMB-JY SMB-J/SMB-K SMA/SMB Series BNC-SMB 75Ω Models Threaded BNC-SMB BNC-SMB Angled M/IP67 BNC-SMB Angled F/IP68 |
| Impedance Matching | 50Ω (standard communication) 75Ω (video transmission) |
Communication devices: 50Ω | SMB-KKK (50Ω) SMB-JY (50Ω) BNC-SMB 75Ω Models |
| Mechanical Requirements | Insertion cycles: >500 times Nut-secured design: 1.5-2x vibration resistance |
Labs/indoor: Standard push-on Vehicles/industry: Vibration-resistant High-frequency testers: Precision threaded |
SMB-JY (M nut-secured) SMB-KJK (M-F/F) SMA/SMB Series |
| Environmental Protection | Standard: No protection Waterproof: IP67/IP68 rated |
Indoor equipment Outdoor/humid environments High-dust industrial areas |
BNC-SMB Angled M/IP67 BNC-SMB Angled F/IP68 SMB-JY (Vibration) |
| Signal Complexity | Single-channel Multi-channel: Tri-port internal design Cross-interface: M/F conversion |
Point-to-point transmission High-density connections System integration |
SMB-KKK (Tri-port) SMB-KJK (M-F/F) SMA/SMB Hybrid Series |
| Termination Method | Soldering/Crimping/Snap-on | PCB connections: Solder/Crimp Quick installation: Snap-on Vibration: Nut-secured |
SMB-J/SMB-J (Solder) SMB-JY(Nut-secured) Threaded BNC-SMB |
4.1 Select SMB connector based on application requirements
The selection of SMB connectors should be based on four core dimensions: frequency requirements, impedance matching, mechanical environment, and environmental protection.Each dimension has its specific technical parameters and application scenarios. Only by properly matching these parameters with the requirements can the best performance of the connector in the system be ensured.
- Frequency requirements are the primary consideration for selecting SMB connectors.
- Impedance matching directly affects the quality of signal transmission.
- The mechanical environment determines the durability of the connector.
- Environmental protection requirements determine the waterproof and dustproof performance of the connector.
4.2 Choose SMB connector for special application scenarios
- For scenarios that require multi-channel signal transmission, the SMB-KKK three-pin female connector is an ideal choice.
- The compatibility and conversion efficiency of the connectors need to be considered in the conversion scenario. SMB-KJK and SMB-JKJ are special adapters for male to dual female or female to dual male conversion, suitable for signal distribution or merging in communication equipment.
- For scenarios that require both waterproofing and vibration resistance, the BNC series adapter products are an ideal choice.
5.RG316 RF cable and SMB adaptation solution
| Core Solution | Key Performance Advantages | Optimal Application Scenarios | Matching Product Models | Precautions |
|---|---|---|---|---|
| RG316 + SMB Tri-port Internal | Single source → triple output Low loss (<2.2dB @3GHz, VSWR ≤1.25) |
Lab signal distribution Base station sector branching |
SMB-KKK (1M→3F) | Ensure sufficient input power Maintain consistent output impedance |
| RG316 + Nut-Secured SMB-JY Male | Vibration-resistant panel mount Industrial protection (IP67 optional) +200℃ rating |
Industrial control panels Vehicle radar interfaces |
SMB-JY (Nut-secured male) | Use torque wrench for installation Avoid over-tightening deformation |
| RG316 + BNC Male to SMB Male | Legacy equipment compatibility High-frequency upgrade (4GHz+) Threaded anti-loosening |
Legacy instrument upgrades Hybrid test systems |
Threaded BNC (M)-to-SMB (M) adapter | Use 50Ω BNC connectors Avoid mixing with 75Ω systems |
| RG316 + SMA/SMB-JK Adapter | SMA female for high-frequency SMB male miniaturization 6GHz system bandwidth |
5G small-cell antennas Network analyzer links |
SMA/SMB-JK | Verify SMA-end device impedance Regularly inspect insertion wear |
| RG316 + SMB Female to Dual Male | High space efficiency Ultra-thin diameter (custom 2.0mm) 100k bend-cycle verified |
Endoscopic imaging Portable medical devices |
SMB-JK (F→dual M) | Use ultra-flexible RG316 variant Maintain ≥15mm bending radius |
| RG316 + Large Hex BNC to Angled SMB Male | Compact space routing EMI-shielded metal housing 40% space savings with angled design |
Cabinet backplane jumpers Compact comm devices |
Large hex BNC(F) →Angled SMB(M) | Avoid repeated bending at same point Recommend armored cable for crush resistance |
| RG316 Pre-assembled Jumper | Factory calibrated: - VSWR ≤1.2 - Loss compensation Plug-and-play: 100% continuity tested |
High-reliability scenarios Mass production deployment |
Customizable all models | Length/connector/impedance options Includes test reports |
6.Detailed parameters of RG316 RF cable
6.1 RG316 RF cable technical parameter table
| Parameter Classification | Parameter Item | Parameter Value |
|---|---|---|
| Basic Information | Model | RG316 |
| Description | High Frequency coaxial cable with FEP (Brown) jacket | |
| Structural Parameters | Inner Conductor | Silver-Plated Copper / Silver-Plated Copper Clad Steel (7×0.175mm) |
| Insulation Layer | Polytetrafluoroethylene (PTFE) Diameter: 1.53mm |
|
| Outer Conductor | Silver-Plated Copper Wire Braiding | |
| Jacket | Fluorinated Ethylene Propylene (Brown), diameter: 2.50mm | |
| Electrical Characteristics | Impedance, nominal | 50 Ω |
| Capacitance, nominal | 106pF/m | |
| Signal Delay, nominal | 4.7ns/m | |
| Insulation Resistance, nominal | 1500MΩ·km | |
| Mechanical Properties | Temperature Rating | 150℃ |
| Minimum Bending Radius | 15mm | |
| Maximum Tensile Strength | 3.4kg | |
| Cable Weight | 17g/m | |
| Attenuation & Power Characteristics | Velocity of Propagation, nominal | 70% |
| Voltage Withstand (AC) | 2000V rms/min | |
| Insulation Resistance , nominal | 1500MΩ-km |
6.2 Table of attenuation and power variation with frequency
| Frequency (MHz) | Attenuation (dB/m) | Power (Watts CW) |
|---|---|---|
| 100 | 0.29 | 420 |
| 400 | 0.58 | 210 |
| 900 | 0.88 | 140 |
| 1000 | 0.93 | 135 |
| 1800 | 1.27 | 100 |
| 2400 | 1.46 | 78 |
| 3000 | 0.65 | 72 |
| 5000 | 2.15 | 61 |
| 6000 | 2.34 | 52 |
SMB Connector Customization Service | Professional RF Connector Solutions
As a professional SMB connector manufacturer, we provide flexible and reliable SMB connector customization services to fully meet the connection needs in high-frequency fields such as communications, testing, and industrial automation.
We support the following customization:
- Various impedance specifications(such as 50Ω or 75Ω) SMB connectors.
- Customized connection structure: straight head, elbow, threaded locking structure (such as SMB-JY), etc.
- Durable high plug-in life design, suitable for frequent disassembly and assembly applications.
- Special SMB adapter: SMB/SMA, SMB/BNC and other multi-interface combinations.
- Customized RF cable assembly: cable length, shielding level, connector type can be customized.
- Ultra-small PCB mounting structure, suitable for compact equipment.
- Multi-port splitter/distributor developmentto meet system integration requirements.
We have a complete R&D, mold making, production and quality control system, and can provide you with highly reliable customized RF connector solutions, with efficient response from sample proofing to batch delivery, and we are a trustworthy SMB connector manufacturer.
Bonfon Office Building, Longgang District, Shenzhen City, Guangdong Province, China
A China-based OEM/ODM RF communications supplier
- Customized RF Adapter Cable
- Custom RF Connectors
- Custom RF Adapter
- Custom Millimeter Wave Test Adapter
- Custom RF Antennas
- Custom RF Coaxial Cables
- Custom RF Coaxial Power Splitter
- Custom RF Coaxial Load
- Custom Electronic Module
- Custom Connectors
- Custom Push Button Switch
- Custom Capacitors
- More New Products
Table of Contents
Owning your OEM/ODM/Private Label for Electronic Devices andComponents is now easier than ever.