The **ALR-611-R** is a high-performance, circular-polarized antenna designed primarily for Radio Frequency Identification (RFID) applications. It is engineered to operate within the global frequency bands used by passive UHF RFID systems. --- ## 1. Core Technical Specifications The electronic performance of the ALR-611-R is defined by its ability to convert electromagnetic waves into electrical signals (and vice versa) with high efficiency and minimal interference. | Feature | Specification | | :--- | :--- | | **Frequency Range** | 860 MHz – 960 MHz (Global) | | **Gain** | 6.0 dBiC (Circular) | | **Polarization** | Right-Hand Circular (RHCP) | | **Beamwidth** | 70° (Horizontal) / 70° (Vertical) | | **VSWR** | ≤ 1.3:1 | | **Input Impedance** | 50 Ohms | | **Max Power Input** | 10 Watts | | **Connector Type** | SMA Female (Side-mount) | --- ## 2. Key Electronic Components & Features ### A. Circular Polarization (RHCP) The antenna utilizes **Right-Hand Circular Polarization**. Electronically, this is significant because it allows the antenna to read RFID tags regardless of their physical orientation. Unlike linear antennas, the circular wave "spirals," ensuring that the tag's antenna is energized as long as it is within the field. ### B. Impedance Matching Network Inside the radome, the antenna contains a matching circuit that ensures the input impedance is exactly **50 Ohms**. This is critical for: * **VSWR Optimization:** Minimizing the Voltage Standing Wave Ratio (VSWR) to prevent power reflections back into the RFID reader. * **Energy Transfer:** Ensuring the maximum amount of RF energy is radiated rather than dissipated as heat. ### C. Wideband Tuning The ALR-611-R is a "Global" antenna. Its electronic design is tuned to cover both the **FCC (902–928 MHz)** and **ETSI (865–868 MHz)** bands. This is achieved through a specific patch geometry that maintains a stable gain across a wide frequency spectrum. ### D. Environmental Shielding Though not an electronic "part" in the traditional sense, the **IP67-rated radome** protects the internal electronic elements (the radiating patch and the microstrip feed) from moisture and dust, which would otherwise alter the dielectric constant and detune the antenna. --- ## 3. Physical Interface The electronic connection is made via a **SMA Female connector**. This requires a high-quality coaxial cable (like LMR-195 or LMR-240) to maintain signal integrity between the Alien Technology reader (or any compatible UHF reader) and the antenna.