The **E.FL-R-SMT** is a specific type of ultra-small surface-mount coaxial connector manufactured by **Hirose Electric**. It is part of the E.FL series, designed for high-frequency signal transmission in compact electronic devices. --- ### 1. Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Connector Type** | Receptacle (Female) | | **Mounting Type** | Surface Mount Technology (SMT) | | **Characteristic Impedance** | 50 Ohms | | **Frequency Range** | DC to 3 GHz | | **V.S.W.R.** | 1.3 Max (at 3 GHz) | | **Mated Height** | 3.0 mm or 3.2 mm (depending on the plug) | --- ### 2. Physical Characteristics * **Ultra-Miniature Design:** It occupies a very small footprint on the PCB, making it ideal for dense circuitry. * **Materials:** * **Center Contact:** Phosphor bronze with gold plating (to ensure high conductivity and oxidation resistance). * **Insulator:** Liquid Crystal Polymer (LCP) or similar heat-resistant resin to withstand SMT reflow soldering. * **Shell:** Brass or Phosphor bronze with silver or gold plating. * **Packaging:** Usually supplied in **Embossed Carrier Tape** (Tape & Reel) for automated pick-and-place assembly. --- ### 3. Applications The E.FL-R-SMT is primarily used for internal RF connections where space is at a premium. Common applications include: 1. **Mobile Communications:** Smartphones, cellular modules, and GPS receivers. 2. **Wireless LAN:** Wi-Fi routers and Bluetooth modules. 3. **IoT Devices:** Small sensor nodes requiring external antenna connections. 4. **Test Points:** Used as a diagnostic port for RF signal testing during manufacturing. --- ### 4. Comparison: E.FL vs. U.FL While both are Hirose standards, they differ in size and performance: * **U.FL:** Smaller mated height (as low as 1.9mm). Very common in laptops and M.2 modules. * **E.FL:** Slightly larger but offers a robust connection and was one of the earlier standards for sub-miniature coaxial interfaces. ---