## Overview of REB-AA-R The **REB-AA-R** is an active GPS (Global Positioning System) antenna module. It is designed for high-sensitivity reception of satellite signals and is commonly used in navigation systems, vehicle tracking, and timing applications. ### Technical Specifications The following table outlines the primary electrical and physical characteristics of the REB-AA-R module: | Parameter | Specification | | :--- | :--- | | **Frequency Range** | 1575.42 MHz ± 1.02 MHz (L1 Band) | | **Polarization** | Right Hand Circular Polarization (RHCP) | | **LNA Gain** | Typically 28 dB | | **Noise Figure** | 1.5 dB (Typical) | | **Operating Voltage** | 3.0V to 5.0V DC | | **Current Consumption** | 10mA to 15mA | | **Output Impedance** | 50 Ohms | | **Connector Type** | Usually SMA or MCX (depending on specific sub-version) | --- ### Core Electronic Components The REB-AA-R functions as an integrated system consisting of several key electronic sections: #### 1. Ceramic Patch Antenna At the top of the module is a ceramic dielectric patch. This is the transducer that converts electromagnetic waves from the GPS satellites into electrical signals. It is tuned specifically to the **1575.42 MHz** frequency. #### 2. Low Noise Amplifier (LNA) Because GPS signals traveling from space are extremely weak (often below the noise floor), the module includes a high-performance LNA. * **Function:** It boosts the weak satellite signal while adding minimal internal noise. * **Filtering:** It often incorporates a **SAW (Surface Acoustic Wave) Filter** to reject out-of-band interference from cellular or Wi-Fi signals. #### 3. Power Management Circuitry The module includes internal decoupling capacitors and sometimes a small voltage regulator to ensure that the LNA receives a "clean" DC supply, which is critical for maintaining a low noise figure. #### 4. Interface and Shielding * **Coaxial Cable/Connector:** Transmits the amplified RF signal to the GPS receiver. * **Metal Shielding:** Most versions are encased in a metal shield to protect the sensitive LNA from Electro-Magnetic Interference (EMI) generated by nearby electronics. --- ### Key Features and Usage * **Active vs. Passive:** Unlike passive antennas, the "Active" nature of the REB-AA-R means it requires power (DC bias) provided through the coaxial center conductor from the GPS receiver. * **Mounting:** It is typically magnetic or adhesive-mounted, allowing it to be placed on a vehicle roof or near a window for a clear view of the sky.