This product description details the RP-SMA Female to I-PEX (U.FL/MHF) Coaxial Pigtail Cable, a highly specialized adapter cable vital for bridging the gap between internal embedded wireless components and external antennas. Utilizing high-performance RG178 coaxial cable, this assembly provides a secure, low-loss, and flexible connection, making it an indispensable component for device prototyping, manufacturing, and enhancing the wireless range of consumer and industrial electronics.
Key Technical Attributes and Performance
This pigtail cable is engineered to facilitate a seamless transition between two vastly different connector standards, ensuring signal integrity across a wide range of frequencies, including Wi-Fi, Bluetooth, and cellular bands.
Connector Interface Bridging
The cable features two distinct connector types on opposing ends, allowing for maximum integration flexibility:
RP-SMA Female (Reverse Polarity SMA Female): This is the external, durable side of the connection. The RP-SMA standard is widely used on wireless devices (e.g., routers, access points, modems) that utilize detachable antennas. The RP-SMA Female end is typically designed to mount flush to the device's enclosure via a bulkhead style, providing a secure, threaded, and reusable interface for connecting the external antenna. This ensures a robust, high-integrity connection suitable for high-frequency transmissions up to 6GHz and beyond.
I-PEX (U.FL/MHF, IPX): This is the internal, miniature side of the connection. The I-PEX connector is the industry standard for embedded radio modules (like Wi-Fi cards, cellular modems, or IoT radio boards) due to its ultra-small footprint. It features a reliable, snap-on mating mechanism, providing a secure yet easily detachable connection directly onto the PCB, which is critical for simplifying manufacturing and device testing.
RG178 Coaxial Cable Performance
The pigtail utilizes RG178 coaxial cable, a key specification chosen for specific mechanical and electrical properties:
High Flexibility: RG178 features a highly flexible fluoropolymer (FEP) jacket and is relatively thin . This flexibility is crucial for routing the cable within tight enclosures, through narrow channels, and around internal components without creating stress points or damaging the cable shielding.
Temperature Resilience: RG178 is rated for high-temperature environments, making it suitable for use inside electronic devices where heat buildup is common.
Electrical Characteristics: While thinner than high-loss cables (like LMR-195), RG178 provides excellent electrical performance for short-run pigtail applications, minimizing attenuation across common ISM bands (2.4 GHz, 5 GHz) and cellular frequencies (LTE/5G Sub-6 GHz).
Simplified Installation and Manufacturing
The pigtail cable is an essential tool for manufacturers, streamlining the assembly process:
Plug-and-Play Assembly: By pre-attaching the cable, manufacturers avoid complex, time-consuming manual soldering of the internal RF connection, leading to reduced labor costs and improved quality control.
Testing Facilitation: The I-PEX connector allows for quick, easy connection and disconnection during the manufacturing testing phase, where external test equipment must temporarily interface with the internal radio module.
Usage Scenarios: Connecting Internal Radios to External Antennas
The RP-SMA Female to I-PEX pigtail is specifically designed for scenarios where the radio module is embedded on a PCB and requires a durable, external antenna connector to enhance wireless performance.
Wireless Routers and Access Points (APs)
This is a primary application. The pigtail connects the internal Wi-Fi radio module (often a mini-PCIe or M.2 card with I-PEX connectors) to the external shell of the router. The RP-SMA Female connector is mounted on the router's rear panel, allowing the user to attach high-gain, detachable external antennas, dramatically improving signal coverage and range.
Cellular Modems and Gateways (4G/5G)
Industrial and commercial cellular modems (used for Fixed Wireless Access, M2M, and IoT gateways) frequently rely on these pigtails. The cable connects the embedded cellular modem (which typically uses an I-PEX connection for its RF ports) to the rugged, chassis-mounted RP-SMA Female ports. This enables the use of high-gain, outdoor-rated antennas (like MIMO panel antennas), which are necessary for achieving optimal 4G/5G speeds and stability over long distances.
Embedded IoT and Telemetry Devices
The pigtail is vital for compact IoT devices that are required to operate reliably over long ranges, such as:
Remote Sensing Units: Connecting a small, I-PEX equipped LoRa or Zigbee radio module inside a rugged enclosure to an external RP-SMA antenna for improved link reliability.
Drones and UAV Telemetry: Used internally to connect the flight control radio or video transmitter (often using I-PEX) to an external antenna mounted on the frame, ensuring stable control and video signals.
Test Benches and Prototyping
The pigtail is an indispensable tool in development laboratories. It allows engineers to quickly connect a bare PCB with an I-PEX connector to standard test equipment (spectrum analyzers, network analyzers) or to various external antennas via the universal RP-SMA interface, speeding up product development and RF characterization.
The RP-SMA Female to I-PEX pigtail cable provides a highly reliable, mechanically robust, and electrically stable bridge, ensuring that the performance of the internal radio module is successfully transferred to the external world via a professional antenna connection.
