The **LMS-4W4-R/Q** is a high-performance **Microstrip Directional Coupler** manufactured by Mini-Circuits. It is designed for applications requiring precise signal monitoring and distribution within the S-band and C-band frequency ranges. --- ### ## Technical Specifications The following table outlines the primary electronic characteristics of the LMS-4W4-R/Q: | Parameter | Value | | :--- | :--- | | **Frequency Range** | 2000 to 4000 MHz (2-4 GHz) | | **Coupling Value** | 4.4 dB ± 0.3 dB | | **Insertion Loss** | 2.5 dB (Typical) | | **Directivity** | 18 dB (Typical) | | **Mainline Return Loss** | 20 dB (Typical) | | **Max Power Input** | 1.0 Watt | | **Operating Temperature** | -40°C to 85°C | --- ### ### Key Electronic Components & Features 1. **Microstrip Design**: The unit utilizes a microstrip transmission line architecture. This allows for a very low profile and makes it ideal for Surface Mount Technology (SMT) assembly on printed circuit boards. 2. **Coupling Mechanism**: The "4W4" designation refers to the specific coupling factor (approximately 4.4 dB). In electronic terms, this means that a portion of the signal traveling through the "In" port is diverted to the "Coupled" port with very high precision. 3. **Materials & Construction**: * **Substrate**: High-frequency laminate optimized for low dielectric loss. * **Termination**: Typically requires external 50-ohm termination on the isolated port if used in a three-port configuration. * **Leads/Terminals**: Gold-plated or SnAgCu (Tin-Silver-Copper) finish for excellent solderability and reliability. 4. **Signal Integrity**: The device is designed for high **Directivity**. In electronic circuits, this ensures that the coupled signal only represents power flowing in one direction (forward), minimizing interference from reflected waves. --- ### ### Typical Application Circuit In a standard RF front-end, the LMS-4W4-R/Q is placed between a power amplifier (PA) and an antenna. ```mermaid graph LR A[Power Amp] -->|Input| B(LMS-4W4-R/Q) B -->|Output| C[Antenna] B -->|Coupled -4.4dB| D[Power Sensor/Detector] ``` 1. **Input Port**: Receives the high-power RF signal. 2. **Output Port**: Passes the majority of the signal to the load. 3. **Coupled Port**: Provides a low-power sample of the input for monitoring. ---