ANT-DB1-VDP-xxx Data Sheet by Product Description 4.52 mm 22.0 mm (0.18 ) The VDP Series is a compact, center-fed antenna (0.87 ) that achieves efficient operation at any or all three frequency bands. Its durable, unobtrusive housing attaches permanently with integral adhesive to flat, non-conductive surfaces such as windows, drywall, ceiling tiles, plastic, etc. The antenna is supplied with 9.8 feet (3m) of RG-174 cable that enters from the bottom to facilitate vertical orientation. It can be terminated in a TNC, standard SMA, or FCC Part 115.0 mm 15 compliant RP-SMA connector. (4.53 ) Features Tri-band (824960MHz, 1.711.99GHz and 2.402.48GHz) Center-fed from the bottom Surface-mount Low VSWR Excellent performance Omni-directional pattern Fully weatherized, durable & unobtrusive TNC, SMA or RP-SMA connector Electrical Specifications Recom. Freq. Range: Band 1: 824960MHz 7.9 mm Band 2: 1.711.99GHz 14.0 mm (0.31 ) Band 3: 2.402.48GHz (0.55 ) SMA, TNC Wavelength: -wave RP-SMA connector connector VSWR: Band 1: 1.5 typ. at center Band 2: 1.9 typ. at center Band 3: 1.9 typ. at center Peak Gain: Band 1: 1.8dBi Band 2: 1.7dBi Band 3: 1.3dBi Impedance: 50-ohms Connector: TNC, SMA or RP-SMA Cable: 9.8 (3 m) RG-174 coax Oper. Temp. Range: 40C to +80C Ordering Information ANT-DB1-VDP-TNC (with TNC connector) ANT-DB1-VDP-SMA (with SMA connector) ANT-DB1-VDP-RPS (with RP-SMA connector) 1 Revised 1/23/14VSWR Graph VSWR Reflected Power 1.530 2.028 2.024 3:1 25% 2:1 11% 1:1 0% CENTER 910.000MHz CENTER 1 825.000MHz SPAN 200.000MHz CENTER 2 450.000MHz 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. 159 Ort Lane, Merlin, OR, US 97532 Phone: +1 541 471 6256 Data Sheet ANT-DB1-VDP-xxx 2 Fax: +1 541 471 6251 by www.linxtechnologies.com