ANT-DB1-RMS-xxx Data Sheet by Product Description 10.0 mm 8.0 mm 14.0 mm Designed for permanent mounting through a metal (0.39 ) (0.31 ) (0.55 ) surface such as an automobile roof or trunk, the compact RMS Series offers excellent performance in a durable and unobtrusive housing. The antenna may be operated at either or both of two frequency 42.0 mm (1.65 ) bands. It is supplied with 14.1 feet (4.3 m) of RG-58 cable and can be terminated in a standard 77.8 mm SMA, Part 15 compliant RP-SMA or a TNC (3.06 ) connector. 23.6 mm (0.93 ) 29.0 mm (1.14 ) Features Dual-band (824960MHz and 1.711.99GHz) Compact & unobtrusive Through-hole mount Standard 13.3413.97 mm Low VSWR (0.5250.550 ) Excellent performance 7.0 mm (0.28 ) Omni-directional pattern Suggested Mounting Holes Fully weatherized Anti-Rotation 11.3 mm 11.4811.56 mm Rugged & damage-resistant (0.44 ) (0.4520.455 ) SMA, RP-SMA or TNC connector 13.1 mm (0.52 ) Electrical Specifications Recom. Freq. Range: Band 1: 824960MHz Band 2: 1.711.99GHz Wavelength: -wave VSWR: Band 1: 1.5 typ. at center Band 2: 2.0 typ. at center Peak Gain: Band 1: 0.6dBi Band 2: 5.3dBi Impedance: 50-ohms Oper. Temp. Range: 40C to +80C Connector: SMA, RP-SMA or TNC Cable: 14.1 (4.3 m) RG-58 coax Ordering Information ANT-DB1-RMS-SMA (with SMA connector) ANT-DB1-RMS-RPS (with RP-SMA connector) ANT-DB1-RMS-TNC (with TNC connector) 1 Revised 12/11/13VSWR Graph VSWR Reflected Power 1.221 1.894 3:1 25% 2:1 11% 1:1 0% CENTER 868.000MHz SPAN 200.000MHz CENTER 1 800.000MHz What is VSWR The Voltage Standing Wave Ratio (VSWR) is a measurement of how well an antenna is matched to a source impedance, typically 50-ohms. It is calculated by measuring the voltage wave that is headed toward the load versus the voltage wave that is reflected back from the load. A perfect match will have a VSWR of 1:1. The higher the first number, the worse the match, and the more inefficient the system. Since a perfect match cannot ever be obtained, some benchmark for performance needs to be set. In the case of antenna VSWR, this is usually 2:1. At this point, 88.9% of the energy sent to the antenna by the transmitter is radiated into free space and 11.1% is either reflected back into the source or lost as heat on the structure of the antenna. In the other direction, 88.9% of the energy recovered by the antenna is transferred into the receiver. As a side note, since the :1 is always implied, many data sheets will remove it and just display the first number. How to Read a VSWR Graph VSWR is usually displayed graphically versus frequency. The lowest point on the graph is the antennas operational center frequency. In most cases, this will be different than the designed center frequency due to fabrication tolerances. The VSWR at that point denotes how close to 50-ohms the antenna gets. Linx specifies the recommended bandwidth as the range where the typical antenna VSWR is less than 2:1. Data Sheet ANT-DB1-RMS-xxx 2 by