ROHO CONNECTOR LIMITED

    The N-type connector, designed by Paul Neill of Bell Labs in the 1940s, has become a cornerstone of RF and microwave systems. Featuring a threaded, weatherproof coupling mechanism and reliable performance up to 11 GHz (and up to 18 GHz for precision versions), it is widely used in cellular infrastructure, radar, satellite communications, and test instrumentation.     One of the key advantages of the N-type interface is its broad compatibility with a wide range of coaxial cables. This versatility allows engineers to select the optimal cable for their specific application—whether prioritizing low loss, flexibility, or cost—while maintaining a consistent connector interface. This article provides an overview of the coaxial cable families that commonly terminate with N-type connectors.     Classification of Compatible Cables     N-type connectors are manufactured with different termination styles—solder, clamp, or crimp—to accommodate various cable diameters and constructions. Cables compatible with N-type connectors generally fall into several categories:     1. RG-Series Cables (Military Designation)     The RG (Radio Guide) series is the most widely recognized family of coaxial cables. Different N-type connector variants are designed to accommodate specific RG cable sizes: Cable Type Typical Applications Key Characteristics RG-8 / RG-8A/U Amateur radio, base stations, low-frequency communications Large diameter, low loss at HF/VHF RG-58 / RG-58A/B/C/U General-purpose RF, test leads, short interconnects Flexible, small diameter, economical RG-141 / RG-141A/U Microwave applications, precision test Low-loss, semi-flexible RG-142 / RG-142A/U Military and aerospace applications High-temperature, low-loss RG-174 Compact, low-power applications Very thin and flexible RG-213 / RG-213/U High-power amateur radio, broadcast Low-loss, robust, handles high power RG-214 / RG-214/U High-power, double-shielded applications Low-loss with extra shielding RG-223 Test equipment, high-frequency applications Low-loss, semi-flexible with solid dielectric RG-225 Specialized military applications Low-loss, high-performance RG-303 Aerospace and defense applications High-temperature, low-loss RG-393 High-performance military applications Low-loss, rugged RG-400 High-reliability test and aerospace applications Double-shielded, high-temperature     2. LMR-Series Cables (Low-Loss, High-Performance)     The LMR (Low-Loss, Multi-purpose, Reliable) series, developed by Times Microwave, offers excellent performance with lower attenuation than traditional RG cables. Common LMR cables compatible with N-type connectors include: Cable Type Typical Applications Key Characteristics LMR-195 Cellular, GPS, Wi-Fi, short jumper cables Flexible, low-loss alternative to RG-58 LMR-200 Medium-length antenna feeds, in-building distribution Low-loss, similar to RG-58 but with better perform...

    In the world of RF and microwave interconnections, the SubMiniature B (SMB) connector has earned a reputation for versatility, convenience, and cost-effectiveness. With its snap-on coupling mechanism and reliable performance up to 4 GHz (and up to 10 GHz in precision variants), the SMB connector has become a staple in telecommunications, base station equipment, automotive electronics, and consumer devices. However, the SMB does not exist in isolation. Several similar connectors—including SMA, SMC, MCX, MMCX, BNC, and FAKRA—offer overlapping capabilities but with distinct differences that engineers must understand when selecting the optimal interface for their application.     This report provides a comprehensive comparison of SMB connectors with their closest analogues, examining the similarities and differences that define their respective roles in modern RF systems.     SMB Connector Overview     Before comparing, let us establish the SMB connector's key attributes: Frequency Range: DC to 4 GHz (standard), up to 10 GHz (precision) Impedance: 50 Ω (primary), 75 Ω (available for video/CATV) Coupling: Snap-on (spring-loaded outer contact) Gender: Male (plug) and female (jack) Size: Small (outer diameter ~4.5–5.0 mm) Mating Cycles: 500 (typical) Typical Applications: Telecommunications, base stations, automotive, GPS, test equipment, consumer electronics     SMB connectors are characterized by their ease of use—the snap-on coupling allows for quick connection and disconnection without tools—and their compact size, which enables dense packaging. They are often used as an alternative to threaded connectors where connection security is less critical than speed and convenience.     SMB vs. SMA Connectors     SMA (SubMiniature version A) connectors are among the most widely recognized high-frequency interfaces. While both SMB and SMA are "subminiature" connectors, they differ fundamentally in coupling mechanism, frequency capability, and application philosophy.     Similarities: Both are 50 Ω impedance (primarily) Both are compact compared to larger connectors like N-Type Both are widely used in telecommunications and test equipment Both have similar gender definitions (male with center pin) Both are available in standard and reverse-polarity versions Both offer good durability with 500 mating cycles     Differences: Feature SMA SMB Frequency Range DC – 18 GHz (standard), 26.5 GHz (precision) DC – 4 GHz (standard), up to 10 GHz (precision) Coupling Threaded (1/4-36 UNF) Snap-on (spring-loaded) Connection Security Very high (threaded) Moderate (snap-on) Vibration Resistance Excellent Good Mating/Unmating Speed Slow (threaded) Fast (snap-on) Mating Cycles 500 (standard), up to 1,000 (precision) 500 Size Small (~5 mm OD) Small (~4.5–5.0 mm OD) Cost Low to moderate Low Typical Applications Test, micr...

    In the complex ecosystem of radio frequency (RF) and microwave systems, one component often goes unnoticed despite its critical role: the RF adapter. These small but essential devices bridge the gap between incompatible interfaces, enabling engineers to connect equipment, cables, and components that would otherwise remain isolated. As RF systems become increasingly diverse—spanning legacy infrastructure, cutting-edge millimeter-wave test setups, and everything in between—the demand for reliable, high-performance adapters has never been greater.     This report provides a comprehensive overview of the classification and key performance characteristics of RF adapters, offering essential guidance for engineers, system integrators, and procurement professionals navigating the complex landscape of RF connectivity.     An RF adapter is a passive device designed to connect two RF components that have different connector interfaces, genders, or impedances. Adapters preserve signal integrity by maintaining the characteristic impedance, minimizing reflections, and ensuring reliable electrical contact between the mating connectors. They are indispensable in test and measurement, telecommunications, aerospace, defense, and countless other applications where incompatible interfaces must be bridged.     Adapters are typically categorized by: Connector types on each end (e.g., SMA to N-Type) Gender (male to female, female to female, male to male) Impedance (50 Ω or 75 Ω) Frequency range (determined by the lower-performing connector) Configuration (straight, right-angle, bulkhead, etc.)     RF adapters can be classified according to several criteria: connector combination, gender configuration, construction style, frequency range, and materials.     The most fundamental classification is based on the connector interfaces on each end. Adapters fall into two broad categories: In-Series Adapters (Same Connector Type)     These adapters connect two connectors of the same family but with different genders or orientations. They are used to change gender, convert between plug and jack, or allow right-angle connections. Configuration Example Use Case Male to Female SMA male to SMA female Extending cable length or changing gender Female to Female N-Type female to N-Type female Connecting two male-terminated cables Male to Male BNC male to BNC male Connecting two female ports or devices Right-Angle SMA male to SMA female (90°) Space-constrained installations Bulkhead SMA female to SMA female (panel mount) Passing signals through a panel or chassis Hermetic SMA female to SMA female (sealed) Vacuum or high-pressure applications     Between-Series Adapters (Different Connector Types)     These adapters connect dissimilar connector families, enabling interface conversion. They are essential for integrating equipment from different generations, vendors, or ...