The **TDJ-R** series typically refers to high-gain, parabolic grid antennas used in wireless communication systems (such as WiFi, WLAN, and point-to-point data links). These antennas are passive electronic components designed to focus electromagnetic waves. Below is a breakdown of the electronic and structural parts of the TDJ-R series. ### 1. Primary Electronic Components | Component | Description | Function | | :--- | :--- | :--- | | **Feed Horn (Dipole)** | The active element at the focal point. | Converts electrical signals from the cable into electromagnetic waves (and vice versa). | | **Grid Reflector** | The large parabolic "dish" made of aluminum or steel rods. | Reflects and focuses signals onto the feed horn to increase gain. | | **Coaxial Connector** | Usually an N-Female or SMA type connector. | Provides the physical interface for the RF cable to connect to the radio/router. | | **Internal Matching Circuit** | Small PCB or tuned bridge inside the feed. | Ensures impedance matching (usually 50 Ohms) to minimize Standing Wave Ratio (SWR). | --- ### 2. Technical Specifications Electronic performance is defined by the following parameters: * **Frequency Range:** Typically covers 2.4 GHz, 5.8 GHz, or specific LTE bands depending on the model (e.g., TDJ-2400R). * **Gain:** Measured in dBi (e.g., 24dBi). Higher gain allows for longer-distance communication. * **Polarization:** Can be adjusted to Vertical or Horizontal by rotating the antenna mounting. * **Beamwidth:** High-gain antennas like the TDJ-R have narrow horizontal and vertical beamwidths (often < 10°), requiring precise alignment. --- ### 3. Assembly and Signal Path The electronic signal follows this path: 1. **Transmission:** The radio sends an electrical signal through a **Coaxial Cable**. 2. **Interface:** The signal enters the **Connector** and reaches the **Feed Horn**. 3. **Radiation:** The **Dipole** inside the horn radiates the signal toward the **Grid Reflector**. 4. **Focusing:** The parabolic shape reflects the waves into a narrow, high-power beam directed at the target. ### 4. Advantages of the "Grid" Design Unlike solid dish antennas, the TDJ-R grid design offers specific electronic and physical benefits: * **Wind Loading:** The gaps in the grid allow wind to pass through, preventing the antenna from shifting and losing signal alignment. * **Front-to-Back Ratio:** The spacing of the grid bars is calculated based on the wavelength ($\lambda$) to ensure maximum reflection with minimal leakage from the rear.