The **FSP-20-R/Q** is a high-performance, single-axis **Fiber Optic Gyroscope (FOG)** designed by Beijing StarNeto Technology. It is an inertial sensor used to measure angular velocity with high precision, typically for stabilization and navigation systems. Below is an explanation of its electronic components and technical architecture. --- ### 1. Key Electronic Specifications The "R/Q" variants typically denote specific interface or performance configurations (often RS-422 digital output). | Parameter | Specification (Typical) | | :--- | :--- | | **Input Range** | ±400°/s to ±1000°/s | | **Bias Stability** | ≤ 0.2°/h to 0.5°/h (1σ) | | **Scale Factor Linearity** | ≤ 100 ppm | | **Interface** | RS-422 (Digital) | | **Input Voltage** | +5V DC | | **Power Consumption** | ≤ 3W | --- ### 2. Core Internal Electronic Parts The FSP-20 series operates on the principle of the **Sagnac Effect**. To achieve this, several critical electronic and optical components are integrated: #### A. The Optical Path (The Sensor) * **SLD (Superluminescent Diode):** The light source. It provides high-intensity, broadband light to minimize noise. * **Fiber Coil:** A precision-wound polarization-maintaining (PM) fiber that acts as the sensing element. * **Y-Waveguide (Integrated Optical Modulator):** A Lithium Niobate ($LiNbO_3$) component that splits the light and performs phase modulation. * **Photodetector (PIN-FET):** Converts the returning interference light signal back into an electrical current. #### B. The Electronic Circuitry (Signal Processing) * **FPGA/DSP Board:** The "brain" of the unit. It performs high-speed digital signal processing, including closed-loop feedback control and demodulation. * **A/D and D/A Converters:** * **A/D:** Converts the analog signal from the photodetector into digital data. * **D/A:** Drives the Y-waveguide for phase compensation. * **Temperature Sensor:** Since FOGs are sensitive to thermal gradients, an internal thermistor provides data to the processor for real-time bias compensation. * **Voltage Regulators:** High-stability power management components to ensure low noise in the SLD and detection circuits. --- ### 3. Functional Diagram of Electronics The electronics follow a **Closed-Loop** architecture: 1. **Light Generation:** SLD emits light. 2. **Sensing:** Light travels through the fiber coil; rotation causes a phase shift. 3. **Detection:** The Photodetector captures the shift as an electrical signal. 4. **Feedback Loop:** The **FPGA** calculates the rotation and sends a "counter-phase" signal via the **D/A** to the Y-waveguide to null the phase shift. 5. **Output:** The amount of feedback required is converted into a digital angular rate and sent via **RS-422**. --- ### 4. Applications Due to its compact size and digital output, the FSP-20-R/Q is commonly found in: * **UAV Payload Stabilization:** Keeping cameras steady. * **Antenna Tracking:** Satellite-on-the-move (SOTM) systems. * **Tactical Weapon Guidance:** Short-range missile or torpedo navigation. * **North-Seeking:** High-precision orientation for mining or surveying.