ROHO CONNECTOR LIMITED

    The IPEX connector family—also widely known as MHF—is the default board-level RF interface for compact wireless devices, from Wi-Fi routers and wearables to 5G modules and millimeter-wave radios. But the connector alone does not determine performance. The micro-coaxial cable it terminates is equally decisive: the wrong cable diameter can compromise shielding, strain the solder joint, or introduce losses that erase the link budget gains the connector was meant to deliver.     Industry selection guidance consistently frames the problem in two dimensions. The first is the crimp barrel or termination cavity of the plug: if the cable is too thick, the rear of the connector cannot close and the shield is not fully captured; if it is too thin, the crimp lacks pull strength and long-term reliability suffers. The second is the electrical trade-off: finer cable (such as 0.81 mm outer diameter) offers superior flexibility for miniature enclosures but carries higher attenuation, while thicker cable (such as 1.37 mm) delivers lower loss at the cost of stiffness and greater mechanical stress on small PCB pads.     This report reviews the coaxial cable families most commonly paired with each IPEX/MHF generation, providing a practical reference for engineers navigating the increasingly narrow gap between connector geometry and cable reality.     First and Second Generation: The Broad-Compatibility Baseline     The first-generation MHF1 and its lower-profile MHF2 sibling are the most forgiving members of the family in terms of cable choice. MHF1 is widely paired with 1.13 mm, 1.32 mm, and 1.37 mm outer-diameter cables, with common cable designations including RG178, RG113, and RG137. These are mature, broadly available micro-coaxial constructions that balance flexibility and loss for applications below roughly 6 GHz.     MHF2 narrows the practical cable window to 1.13 mm and 1.32 mm, reflecting its reduced mated height and tighter mechanical envelope. In both generations, the cable diameters are large enough to be handled in volume assembly without extreme process control, which is why MHF1 remains the mechanically interchangeable counterpart to the long-standing U.FL interface and continues to appear in routers, industrial terminals, and legacy network cards.     Third Generation: The Transition to Finer Cable     The MHF3 generation represents the point at which the IPEX family begins to demand a different class of cable. Its reduced terminal geometry is optimized for 0.81 mm outer-diameter micro-coaxial cable, often described generically as “superfine” or RG081-type cable. Some sources also cite 0.64 mm cable as compatible with MHF3-class interfaces.     The shift to 0.81 mm is not cosmetic. It enables the lower mated height and smaller footprint that MHF3 was designed to achieve, but it also raises the bar for termination quality. The center c...

    The SMA (SubMiniature version A) connector remains one of the most widely used RF interfaces in the world. With its threaded coupling, 50-ohm impedance, and excellent performance from DC to 18 GHz (and up to 26.5 GHz in precision versions), the SMA connector is a staple in telecommunications, test and measurement, aerospace, and defense. A common question for engineers and technicians is: what coaxial cables are typically terminated with SMA connectors?     The answer depends on the application—whether it is a flexible test lead, a low-loss antenna feeder, or a semi-rigid assembly for a microwave module. This article reviews the most common coaxial cable families used with SMA connectors, without reference to any specific manufacturer.     Impedance: 50 Ω Standard, 75 Ω Available     SMA connectors are predominantly designed for 50-ohm systems, the standard for RF, microwave, and wireless communications. A limited number of 75-ohm SMA variants exist for video and broadcast applications, but they are far less common. All cables discussed here are 50-ohm types unless otherwise noted.     Common Coaxial Cable Types for SMA Connectors     SMA connectors are available with crimp, solder, and clamp attachment styles to accommodate a wide range of cable diameters. The following cable families are most frequently paired with SMA connectors.     1. Flexible Cables (RG-Series and Equivalent)     Flexible cables are the most common choice for general-purpose SMA assemblies, including test leads, jumper cables, and short interconnects. They offer good flexibility at the cost of higher loss compared to semi-rigid or low-loss foam cables.     Cable Type Typical Applications Key Characteristics RG-58/U General RF, test leads, amateur radio Moderate loss, flexible, economical RG-174/U Compact, low-power, portable devices Very thin, highly flexible, higher loss RG-178/U Ultra-compact, handheld radios, GPS Very small diameter, flexible RG-188/U High-temperature, flexible applications Similar to RG-178 but with PTFE dielectric RG-316/U Low-loss flexible, test and measurement Smaller than RG-58, low loss, flexible RG-400/U High-reliability test, aerospace Double-shielded, low loss, high temperature     2. Low-Loss Flexible Cables (Foam-Dielectric)     Low-loss flexible cables use a foam dielectric and a braided outer conductor to achieve lower attenuation than standard RG cables while remaining flexible. They are commonly used for antenna feeders, jumper assemblies, and test leads where loss matters.     Cable Type Typical Applications Key Characteristics LMR-100 Ultra-compact, short jumpers Very thin, low loss for its size LMR-195 General-purpose RF, GPS, Wi-Fi Flexible, low loss, similar to RG-58 but better LMR-200 Medium-length runs, in-building Low loss, flexible, good for 2.4 GHz LMR-240 Antenna feeders, wireless infrastr...

    As 5G networks densify and small cell deployments accelerate, the NEX10 connector interface has emerged as a compact, high-performance solution for space-constrained RF systems. Standardized under IEC 61169-71 for 50-ohm RF coaxial connectors with a 5.0 mm inner diameter outer conductor, the NEX10 interface offers a 50% smaller footprint than the widely used 4.3-10 connector, enabling dramatically higher port density on radios, antennas, and filter outputs.     A key practical question for engineers and installers is: what coaxial cables are typically terminated with NEX10 connectors? The answer depends on the application—whether it is a short jumper inside a remote radio head or a low-loss feeder connection at an antenna port.     A Connector Designed for Compact, Low-PIM Applications     The NEX10 interface was developed to address the evolving needs of small cell and distributed antenna systems (DAS). Its key attributes include: Frequency range: DC to 20 GHz Impedance: 50 Ω PIM performance: Better than –166 dBc (typical) Power handling: Approximately 100 W at 2 GHz (at 85°C) Flange height: 12.7 mm minimum Environmental protection: IP68 when mated Coupling options: Screw, hand-screw, and push-pull (quick lock)     These characteristics make NEX10 ideal for applications requiring PIM stability in a compact size, including small cells, MIMO antennas, and in-building DAS.     Commonly Used Coaxial Cables with NEX10 Connectors     The NEX10 interface is optimized for a specific range of cable sizes, primarily focusing on small-diameter flexible and corrugated cables. The following cable families are most commonly paired with NEX10 connectors.     1. 1/4-Inch Superflexible Corrugated Cables     The most widely used cable type with NEX10 connectors is 1/4-inch superflexible corrugated cable. This cable offers an excellent balance of low loss, flexibility, and power handling, making it ideal for jumper connections between remote radio heads (RRHs) and antennas, as well as short feeder runs.     Typical 1/4-inch superflexible cables compatible with NEX10 connectors include:     Cable Designation Characteristics Typical Applications SPP-250-LLPL PTFE dielectric, 76% velocity of propagation, corrugated Low-PIM jumpers, plenum installations SPF-250 Corrugated, low-PIM construction General-purpose jumpers SPO-250 Corrugated, low-PIM Outdoor-rated assemblies 1/4" Superflexible 50 Ω corrugated, flexible Tight-space installations, bulkhead connections     These cables are available in standard and low-PIM versions, with PIM performance typically better than –160 dBc. Cable assemblies using these cables operate to approximately 5.8–6 GHz and achieve VSWR of 1.4:1 to 1.5:1.     2. 3/8-Inch Corrugated Cables     For applications requiring slightly lower loss and higher power handli...