Glossary of Terms for STI-CO Antennas
Antenna System: An antenna system includes everything needed to install the antenna in one package, including antenna, cable, couplers, connectors and filters (if needed).
Attenuation: A loss of signal strength in a lightwave, electrical or radio signal usually related to the distance the signal must travel (e.g. fiber optic transmission must be regenerated approx. every 30 miles). Fiber optic attenuation is caused by transparency of the fiber, bending the fiber at too small of a radius, nicks in the fiber, splices, poor fiber terminals, FOT’s, etc. Electrical attenuation is caused by the resistance of the conductor, poor (corroded) connections, poor shielding, induction, RFI, etc. Radio signal attenuation may be due to atmospheric conditions, sun spots, antenna design / positioning, obstacles, etc.
Bandwidth: The difference between the lowest and highest frequency of operation as defined by a 2:1 SWR.
Beamwidth: In an antenna, the angular sector in degrees of the radiated power pattern at the half-power (3dB) point.
Cable Kit: Identifies the transmission line material used to interconnect between antenna and two-way radio equipment. Kit is comprised of a specified length of cable such as RG-58/U,
or low loss cable, and one connector.
CDMA Code Division Multiple Access - A way to increase channel capacity by using code sequences as traffic channels in a common radio channel. This technology was originally developed for military use over 30 years ago. Also -- A digital signal multiplexing technique where each signal is split into many chips of data, each of which is tagged with a particular code. During transmission, the chips are spread over a band of frequencies, then reassembled at the receiving end. This technique permits many different signals to be co-located in the same frequency band.
Cell: The basic geographical unit of a cellular communications system. Service coverage of a given area is based on an interlocking network of cells, each with a radio base station (transmitter/receiver) at its center. The size of each cell is determined by the terrain and forecasted number of users.
Circular Polarization: In an antenna, where the tip of the field vector, as viewed in the direction of propagation, rotates either clockwise (right hand) or counterclockwise (left hand).
Collapsed Height (Inches): For certain models used to demonstrate the portability of the unit, measured as the largest dimension when the unit is collapsed.
Concealed Internal Antenna System: Antenna is mounted inside the vehicle above the headliner near the rear or side window of the car,
van, or SUV. Available in CEL, or CEL/PCS.
Connector (Choose One) : Identifies choice of one standard connector that will connect the cable or feed line to the two-way radio equipment. For example: PL-259, mini-UHF, BNC, TNC, etc.
Covert Fender Mount: Exactly matches the antenna supplied by the auto manufacturer. For this reason, orders must contain information on the year, make, model, and trim line of car. Antenna may be mounted on the front or rear fender depending on the vehicle. Available in HF, VHF, UHF, CEL, VHF/UHF, and VHF/CEL.
Covert Cellular Style: Modeled after popular cell phone antennas used for hands-free operation or tracking systems.
Available in VHF, UHF, VHF/UHF and VHF/CEL frequency ranges.
- GLMT (Glass mount): Mounted on glass on side or rear window.
- TKLP (Trunk Lip Mount): Mounted on trunk lid of sedans.
- MGNT (Magnet Mount): Magnet in base to quickly mount on roof or trunk.
- ROOF (Roof Mount): Mounted in center of roof.
- Closed Coil: Mast has solid coil look.
- Open Coil: Mast has a curly-Q coil.
Cross Polarization: In an antenna, polarization orthogonal to a specified reference.
dB Decibel; a logarithmic unit of power or intensity; 3 dB is twice the power.
dBi Decibel, Isotropic; decibel referenced to the gain of a theoretical isotropic radiator.
dBm Decibel, milliwatt; decibel referenced to one milliwatt into 50 ohms (typical for RF systems).
Dipole Antenna: Any one of a class of antennas producing a pattern with a node or zero level at each end.
Directive Gain: In a given direction, 4pi times ratio of the radiation intensity in that direction to the total power radiated by the antenna.
DB (Dual Band) Two frequency bands are combined on one antenna.
Electromagnetic Interference (EMI): Any electromagnetic disturbance that interrupts, obstructs, or otherwise degrades or limits the effective performance of electronics/electrical equipment. It can be induced intentionally, as in some forms of electronic warfare, or unintentionally, as a result of spurious emissions and responses, intermodulation products, and the like. EMI is also an engineering term used to designate interference in a piece of electronic equipment caused by another piece of electronic or other equipment. EMI sometimes refers to interference caused by nuclear explosion. Synonym: radio frequency interference.
Feed line: Cable that is a integral part of the antenna and cannot be removed and may not be substituted with another cable type.
Finish: Indicates the color and process applied to the antenna, for example, black chrome, bright chrome, black anodized, black painted, etc.
Frequency: The reciprocal of a signal's period is its frequency (units of Hertz -- or cycles per second -- actually 1/second, dimensionally).
Frequency Band (STI-CO Specific)
HF (High Frequency): 30 to 50 MHz.
VHF (Very High Frequency): 150 to 174 MHz.
UHF (Ultra High Frequency): 406 to 512 MHz.
CEL (Cellular Band): 806 to 896 MHz. 700 (Public Safety Band): 760-860 MHz.
PCS (Personal Communications Service): 1850 to 1990 MHz.
GPS (Global Positioning Satellite): 1575 MHz.
MIC (Microwave): 1100 to 2500 MHz
VID (Video): 2000 to 3000 MHz.
* Higher and lower frequencies are available on special request
Frequency Range (MHz): The range of frequencies in which antennas will operate regardless of bandwidth.
Gain, dB: A ratio of output divided by input, expressed in decibels. In antennas, the ratio of the radiation intensity, in a given direction, to the radiation intensity that would be obtained if the power accepted by the antenna were radiated equally in all directions (isotropically).
Gain, dBd : Antenna gain, expressed in decibels referenced to a half wave dipole.
Gain, dBi : Antenna gain, expressed in decibels referenced to a theoretical isotropic radiator.
Gain, dBic : Antenna gain, expressed in decibels referenced to a theoretical isotropic radiator that is circularly polarized.
Gain (dbd): The amount of gain antenna presents as compared to a dipole antenna.
GPRS General Packet Radio Service: A planned improvement for GSM networks that implements packet switching for data communications. Instead of sending data on dedicated circuits, a packet-switching network divides the information into packets and transmits them on any of the network's available channels.
Horizontal Polarization: In an antenna, a linearly polarized electric field vector whose direction is horizontal relative to ground or some arbitrary coordinate system.
Interoperable Antenna System: Up to four transmission systems are combined into one antenna AVN (106-130 MHz), VHF (150-174 MHz), UHF (380-512MHz), and CEL (760-896 MHz).
Isolation (db): The amount of attenuation between two ports of a coupler.
Isotropic Radiator: A hypothetical, lossless antenna having equal radiation intensity in all directions; used as a zero-dB gain reference in pattern measurements or directivity calculations.
Land-Mobile Service: A mobile service between base stations and land-mobile stations, or between land-mobile stations.
Land Mobile Station: A mobile station in the land-mobile service capable of surface movement within the geographical limits of a country or continent.
Low Profile Antennas: These antennas extend no more than 6 inches above the body of the vehicle for use in rugged environments where longer antennas would be broken. Commonly used on buses, trains, and trucks. Available in rugged cast aluminum in VHF and UHF; also, incased in an ABS plastic radome in UHF, CEL, and CEL/GPS.
Maximum Height (Inches): The total height of the mast and mounting assembly as measured from the antenna base to the tip, including any protective ends.
Mast Appearance: A description of how the mast looks to distinguish different standard styles, i.e. closed coil, open coil, telescoping, fixed, spiral.
Mast or Radiating Material: Identifies antenna whip material to help identify how the unit will perform electrically or in various environmental conditions, i.e.: stainless steel, cast aluminum, tubular aluminum, fiberglass, rubber-coated Nitinol, etc.
Mobile Service: A radio communication service between mobile and fixed stations, or between mobile stations. Depending on whether one or more of the earth stations are on land, sea, or air, the service would be called land mobile, maritime mobile, or aeronautical mobile.
Monopole Antenna: One constructed above a ground plane producing a radiation pattern approximating that of a dipole in the half-space above the ground plane.
NB (Narrow Band): Indicates that the antenna does not cover the entire frequency band therefore a center operating frequency is required to factory tune antenna.
Mounting Hardware (Supplied): A description of the hardware kit that is included with the antenna, i.e.: VHB adhesive, stainless steel screw, OEM hardware, NMO hardware, etc.
Mounting Style: A description of how the antenna is to be affixed to a mounting surface. For example, peel and stick, glass mount, magnet mount, trunk lip mount, NMO mount, stake mount, lanyard mount, etc.
Nulls: In an antenna, near zero-level signals of sharp angular width seen in a radiation patterns. The opposite of lobes.
Omni-directionality: That property of an antenna exhibiting a non-directional pattern in a given plane.
Parasitic Element: A radiating element, not connected to the feed lines of an antenna, which affects the radiation pattern and/or impedance of an antenna
Pattern: A description of how the antenna energy is focused, either omni-directional or directional.
PCS Personal Communications Service: A generic term for a mass-market mobile personal communications service, independent of the technology used to provide it. Also, a type of digital wireless network in North America that operates in the 1,900 MHz frequency band. Example: Sprint PCS, which uses CDMA technology.
Phased Array: An antenna comprised of multiple identical radiating elements in a regular arrangement and fed to obtain a prescribed radiation pattern.
Polarization: In an antenna, the direction in which the electric field vector is aligned during the passage of at least one full cycle.
Power Rating (Watts): The maximum safe continuous amount of power that can be applied to antenna without damage.
Principal Planes: In an antenna, the azimuth and elevation plane radiation pattern cuts usually taken through the peak of the beam.
Public Safety Antennas: New innovative antennas for non-covert police cars, fire and emergency vehicles, tow trucks, etc. --- any vehicle using a light bar. Antennas are easily mounted on top of plastic or metal light bars, eliminating need to drill extra holes in vehicle. Specifically designed not to interfere with other light bar components such as strobe or LED lights on most popular light bars. Antennas are available in VHF, UHF, and CEL.
QB (Quad Band): Four frequency bands are combined on one antenna.
Radiation Pattern: A graphical representation in either polar or rectangular coordinates of the spatial energy distributions of an antenna.
Radio Frequency (RF): Generally, a frequency from approximately 50 kHz to 3 GHz. RF is usually referred to whenever a signal is radiated through the air.
Reflector Element: In an antenna, a parasitic element located in a direction other than forward of the driven element intended to increase the directivity of the antenna in the forward direction.
Return Loss: Expressed in decibels, Return Loss is a measure of VSWR.
SB (Superband®): Indicates that the antenna covers the entire frequency band.
Side Lobe: In an antenna, a radiation lobe in any direction other than that of the major lobe.
Spread Spectrum (SS): A communication technique that spreads a signal bandwidth over a wide range of frequencies for transmission and then de-spreads it to the original data bandwidth at the receiver.
Surveillance Van Antenna System: Up to four antennas are encased inside a 10-foot PVC pipe commonly used by contractors. Used on roof racks of vans or trucks. Available in multiple combinations of VHF, UHF, CEL and MIC.
Tactical Antennas: Antennas specifically designed to be used in field operations away from established facilities, or to improve range and operation of portable radios. Antennas are compact and lightweight and, along with cable and various mounting options, come with a case for easy portability. Compact Portable Antenna available in VHF and UHF. Field Portable Antenna available in single or double kits with VHF, UHF and CEL.
TB (Tri Band): Three frequency bands are combined on one antenna.
Vertical Polarization: In an antenna, a linearly polarized electric field vector whose direction is vertical relative to ground or some arbitrary coordinate system.
VSWR: Voltage Standing Wave Ratio.
