J
K
Q
U
X
Z
1G
First Generation cellular - analog cellular, including AMPS
2G
Second Generation cellular - digital cellular including TDMA, CDMA and SGM systems.
3G
Next generation wireless network technology. The term 3G refers to third generation wireless networks. These networks offer the promise of eventually being able to deliver voice, data and multimedia content at rates as high as 2 Mbps
802.11
A family of specifications related to wireless networking. See 802.11a, 802.11b, and 802.11g.
802.11a
One of three wireless networking specifications under the Wi-Fi rubric. 802.11a uses the 5 GHz band and runs at 54 Mbps. 802.11a is little used outside specific business situations.
802.11b
The most common of the three wireless networking specifications included in the Wi-Fi certification mark. 802.11b uses the 2.4 GHz band and runs at 11 Mbps.
802.11g
The newest of the three Wi-Fi specifications. 802.11g is backward compatible with 802.11b, thanks in part to its use of the 2.4 GHz band, and it runs at the 54 Mbps speed of 802.11a. Most new equipment uses 802.11g.
Accelerated Test
A test designed to shorten the test time by increasing the frequency or duration of environmental stress expected to occur during normal application.
Adaptive (Smart) Antenna
An antenna system having circuit elements associated with its radiating elements such that one or more of the antenna properties are controlled by the received signal.
AMPS
Advanced Mobile Phone Service. Currently the cellular telephone standard in the US.
Antenna
A metallic device used in the transmission and reception of electromagnetic waves. An antenna is a passive or an active device which permits transmission.
Antenna Power Gain
The ratio of the antenna’s maximum radiation intensity in a stated direction to the maximum radiation intensity of a reference antenna (dipole, isotropic antenna) with identical power applied to both.
ASCII
American Standard Code for Information Interchange.
Attenuation
The loss in power of electromagnetic signals between transmission and reception points.
Azimuth
Horizontal direction expressed as the angular distance between the direction of a fixed point (as the observer's heading) and the direction of the object.
Bandwidth
A range of consecutive frequencies comprised of a band (i.e. the US cellular bandwidth is 72 MHz wide between the frequencies of 824 MHz - 890 MHz) over which an antenna shall perform without the need of any adjustment.
Base Station
In a cellular communication system, a base station could be considered a central mode of transmission and reception for the network. Currently, this station includes an omnidirectional antenna or several sectoral antennas.
Beamwidth
The angle of signal coverage provided by an antenna. Beamwidth typically decreases as antenna gain increases.
Braid
The interwoven outer conductive layer of coaxial cable made up of several bare conductors coming together to form a solid or nearly solid layer or shield. Braid is rated by percentage of coverage and by pixels per inch. Pixels per inch indicate the number of crossings of the braid in one inch of cable.
Braid Coverage
See Shield Effectiveness
Bridge
A device which connects two or more physical networks and forwards data between them.
Broadband
Refers to networks capable of delivering high bandwidth.
Cable Loss
A numeric value describing the amount or signal loss from one point on a length of cable to another. This is measured in decibels (dB).
Capacitor
A capacitor is a storage device for electrical energy. A capacitor has two metal plates separated by an insulator.
CDMA
Code Division Multiple Access. A numerical standard for data transmission.
Center Conductor
A solid or stranded electrical conductor generally composed of copper and located at the center of the coaxial cable.
Center Fed
Transmission line connection at the electrical center of an antenna radiator.
Channel
A particular set of one transmit frequency and one receive frequency in the RF band.
Coaxial Cable
Cable consisting of a single copper conductor in the center surrounded by a plastic layer for insulation and a braided metal outer shield. Coax is used to transfer radio frequency energy from the transmitter to the antenna.
Collinear Array
A system of two or more antenna radiators arranged in a line and connected end-to-end to generate a directed field pattern (serial linear topology).
Conductor
A metal body such as tubing, rod or wire which permits current to travel continuously along its length.
Coupler
Referring to on-glass antennas, a coupler is the two-piece interface between the coaxial cable on the inside of the glass and the radiator on the outside of the vehicle. It is designed to efficiently couple RF energy through the glass. The formulation of the glass and glass thickness normally have a substantial effect on coupler performance.
Current Loop
A point of current maxima (antinode) on an antenna.
Current Node
A point of current minima on an antenna.
Decibels (dB)
See basic antenna concepts.
dBd
Quantification of the gain for an antenna in comparison with the gain of a dipole.
dBi
The dB power relative to an isotropic source.
dBm
A measure of power based upon the decibel scale, but referenced to the milliWatt: i.e. 1dBm = .001 Watt. dBm is often used to describe absolute power level where the point of reference is 1 milliWatt. In high power applications the dBW is often used with a reference of 1 Watt.
dBW
The ratio of the power to one Watt expressed in decibels.
dc ground
An antenna which is a dead short to a DC current, and has a shunt fed design. To RF it is not seen as a short.
Dipole
An antenna--usually a half wavelength long--split at the exact center for connection to a feed line. Also called a “doublet”.
Directional Antenna
An antenna having the property of radiating or receiving electromagnetic waves more effectively in some directions than others.
Directivity
The theoretical characteristic of an antenna to concentrate power in only one direction, whether transmitting or receiving.
Driven Element
A radiator element of an antenna system to which the transmission line is connected.
Efficiency
The ratio of useful output to input power, determined in antenna systems by losses in the system including losses in nearby objects.
Electrically Small Antenna
Some antennas (such as various low profile antennas, some base loaded whips and often rubber duckie portable antennas) are physically considerably smaller than either a 1/2 or 1/4 wavelength antenna. The challenge with electrically small antennas is to maintain radiating efficiency. A greater challenge is to design an antenna with adequate bandwidth. Careful design using high quality materials often overcome these obstacles.
Embedded Antennas
Antennas directly integrated into a system such as an access point, a terminal or a handset. In most cases, this antenna is matched to the system and can not be used in other applications without modification.
E-Plane and H-Plane
Antenna measurements in general and radiation patterns in particular must be performed with polarization in mind. Since polarization is defined as having the same orientation as an antenna’s electric field vector, it is common practice to refer to measurements aligned with either the electric vector ( E-plane) or magnetic vector (H-plane).
ERP
Effective Radiated Power.
Fiber Optic Cable
A cable, consisting of a center glass core surrounded by layers of plastic that transmits data using light rather than electricity. It has the ability to carry more information over much longer distance.
Field Strength
An absolute measure in one direction of the electromagnetic wave field generated by an antenna at some distance away from the antenna.
Field Tunable
Antennas identified as Field Tunable are shipped with a cut chart the installer uses to select a desired operating frequency by tuning the antenna to resonance. Cut charts should be used as guidelines and are adequately accurate for many applications. However, Radiall/Larsen recommends using appropriate RF measurement devices whenever possible for more accurate tuning.
Frequency
The number of cycles per second of a wave (i.e. sound wave).
Front-To-Back Ratio
The ratio of radiated power off the front to the back of a directive antenna. A dipole would have a ratio of 1, for example.
Full Duplex
Refers to a communication system or equipment capable of transmission and reception simultaneously.
Gain
Gain is the practical value of the directivity of an antenna. It takes into account the efficiency of the complete structure.
Gigahertz (GHz)
One billion cycles per second.
GPRS
General Packet Radio Service. GPRS is a portion of the GSM standard.
GPS
Global Positional Satellite or Global Positioning System.
Ground Plane
A man made system of conductors placed below an antenna to serve as an earth ground.
Handoff
The process of maintaining a radio link between a cellular radio telephone and the cellular system. The handoff occurs when the radio telephone moves out of range of one cell site and comes into range of another, relying on Received Signal Strength Indication (RSSI) to determine when handoff is necessary.
Hertz (Hz)
A unit of frequency equal to one cycle per second.
H-plane
See E-Plane.
Impedance
The Ohmic value of an antenna feed point, matching section or transmission line at a radio frequency. An impedance may contain a reactance as well as a resistance component.
Lightning Protector
A device designed to divert large surges of current such as a lightning strike from reaching the RF equipment. There are many types of lightning protectors including Quarter Wave Stub and Gas Discharge Tubes.
Load
The electrical entity to which power is delivered. The antenna system is a load for a transmitter.
Megahertz (MHz)
1 million cycles per second.
Mobile Antenna
Refers to any antenna mounted on a vehicle. Includes a radiating element and a mechanism to fix the antenna to the vehicle.
Monopole
Literally, one pole, such as a vertical radiator operated against the earth or a ground plane. A handheld rubber duck type of antenna will most likely be a monopole.
Mount
A mount is the device onto which a mobile antenna attaches. It is the mechanical and electrical interface between an antenna and the vehicle.
NMO
Perhaps the most prolific of all mobile antenna mounts is the NMO. It enables one mount, inserted in a drilled hole in the vehicle body, to be used over the lifetime of the vehicle with many screw-on antennas.
Noise
Any unwanted and unmodulated energy that is always present to some extent within any signal.
Omnidirectional
An antenna providing a 360-degree transmission pattern. This type of antenna is used when coverage in all directions is required.
Page
A message broadcast to a group of cellular telephone units which uniquely identifies a particular cellular telephone based on the information contained in the message. This cellular unit will normally acknowledge the message and enter a ringing state.
Paging Channel
A forward control channel used to page cellular telephones and send orders.
Parabolic Antenna
An antenna consisting of a parabolic reflector and a radiating or receiving element at or near its focus. Parabolic antennas are very directive and includes a preliminary source and a parabolic reflector to focus the energy.
PCB
Printed Circuit Board.
PCS
Personal Communication Service is a frequency band (1850 - 1990 MHz) assigned by the Federal Communication Commission.
Planar Array
An antenna in which all of the elements, both active and parasitic, are in one plane.
Point-to-Point:
A communications channel running from one point to another.
Point-to-Multipoint:
A communications channel running from one point to several other points.
Polarization
The sense of the wave radiated by an antenna. This can be horizontal, vertical, elliptical or circular (left or right hand circularity) depending on the design and application.
POS
Point of Sale
Printed Antenna
All antennas made by means of a printed circuit process.
Radiation Pattern
The graphical representation of the relative field strength radiated from an antenna in a given plane, plotted against the angular distance from a given reference.
Radiator
A discrete conductor radiating RF energy in an antenna system.
Radome
A typically rigid dielectric cover over the radiating portion of an antenna, and nearly always separated from the radiator by an air gap. A radome (the merger of radar and dome) has the purpose of protecting the radiator from natural weather phenomena and contamination by dirt. It usually includes aerodynamic shaping to minimize wind loading.
Receiver (Rx)
An electronic device which enables a particular signal to be separated from all and converts the signal format into a format for video, voice or data.
Relative Antenna Power Gain
The ratio of the average radiation intensity of the test antenna to the average radiation of a reference antenna with all other conditions remaining equal.
RFDC/RFID
Radio Frequency Data Communications/Radio Frequency IDentification.
RSSi
Received Signal Strength Indicator. Provides a signal for logic circuit processing that is a function of received RF signal strength. RSSI is used both by the switch and the mobile or portable.
SAT
Supervisory Audio Tone. One of three tones in 6 KHz region transmitted by the cell site and transponded (returned) by a cellular telephone.
Sectoral Antenna
A directive antenna with a radiation pattern aperture (3 dB beamwidth) larger than 45°. Sectoral antennas are generally used for point-to-multipoint systems or combined with several antennas to create a base station.
Shield Effectiveness
A measurement of how well the shielding material (braid, solid tape, etc.) protects the external environment from radiation produced by the center conductor.
Standard Impedance
The nominal impedance associated with the transmission line and test equipment.
Standing Wave Radio (SWR)
See VSWR.
TDMA
Time Division Multiple Access is a communication protocol allowing multiple users on the same transmission channel.
Transmission Line
The connecting link allowing the radio frequency energy generated by the radio to be delivered to the antenna. (Coaxial cable, microstrip or coplanar lines in our industry.)
Transmitter
An electronic device consisting of oscillator, modulator and other circuits which produce a radio electromagnetic wave signal for radiation into the atmosphere by an antenna.
Voltage Standing Wave Ratio (VSWR)
VSWR of the antenna is the ratio of the maximum to minimum values of voltage in the standing wave pattern appearing along a lossless 50 Ohms transmission line with an antenna as the load.
WAN
Wide Area Network. A network connecting computers within every large areas, such as states, countries, and the world.
Wave Length
See Basic Antenna Concepts.
Whip
The vertical portion of the antenna assembly acting as the radiator of the radio frequency energy.
Wireless
A new all-encompassing "buzzword" which describes what used to be called "radio", but which typically also implies some of the newer cellular or digital radio technologies as well.
WISP
Wireless Internet Service Provider
WLAN
Wireless Local Area Network. A short range computer to computer wireless data communications network.
WPAN
Wireless Personal Area Network - Bluetooth Technology
WWAN
Wireless Wide Area Network. WWAN uses various devices—telephone lines, satellite dishes, and radio waves—to service an area broader than can be covered by a WLAN, although typically with lower bandwidth.
Yagi
A directional, gain antenna utilizing one or more parasitic elements. Named after one of the Japanese inventors (Yagi and Uda).
|
|
|
 Electronic Catalog >>
Brochures >>
One Minute Survey >
Custom Design Request >>
RoHS link >>
Click below to download Adobe Acrobat Reader!
Corporate >>
Antenna Division >>
|
