The **WJM-123-R** is a specific model identifier typically associated with **RF (Radio Frequency) Wireless Transceiver Modules** or specialized connectors, often found in industrial automation or consumer electronics remote controls. Below is an overview of the electronic components and technical specifications common to this part series. ### 1. Technical Specifications Table Most versions of the WJM-123-R operate within the Sub-1GHz spectrum, designed for low-power data transmission. | Parameter | Typical Value | Unit | | :--- | :--- | :--- | | **Operating Voltage** | 3.0V - 5.5V | VDC | | **Operating Frequency** | 433.92 (standard) | MHz | | **Modulation Type** | ASK / OOK | - | | **Data Rate** | 2.4 - 10 | Kbps | | **Operating Temp** | -30 to +85 | °C | | **Sensitivity** | -105 to -110 | dBm | --- ### 2. Key Electronic Components The internal architecture of the WJM-123-R generally consists of the following sections: #### A. The RF Front-End * **SAW Filter:** Surface Acoustic Wave filter used to suppress out-of-band interference and improve selectivity. * **LNA (Low Noise Amplifier):** Amplifies the weak incoming radio signal from the antenna without adding significant noise. #### B. The Oscillator Section * **Crystal Reference:** Usually a high-precision crystal (e.g., 6.7458 MHz or 13.56 MHz depending on the multiplier) that stabilizes the frequency to prevent "drift" caused by temperature changes. #### C. Demodulator Circuitry * **Comparator/Data Slicer:** Converts the analog RF envelope into a digital square wave (TTL level) that can be read by a Microcontroller (MCU). --- ### 3. Pin Configuration The physical interface usually consists of a 4-pin or 5-pin header: | Pin Number | Label | Description | | :--- | :--- | :--- | | 1 | **ANT** | External Antenna connection (approx. 17cm wire) | | 2 | **VCC** | Positive Power Supply | | 3 | **DATA** | Digital Output (to MCU) | | 4 | **GND** | Ground | --- ### 4. Common Applications * **Remote Keyless Entry (RKE):** Garage door openers and car alarms. * **Wireless Security:** PIR sensors and door/window contacts. * **Home Automation:** Wireless light switches and smart plugs. * **Industrial Telemetry:** Remote monitoring of environmental sensors. ---