RF & Wireless

2G - Second Generation Wireless Technology

2G stands for the second generation of mobile wireless communication technology, which uses digital technologies for mobile communication. 2G technologies can be divided into TDMA-based (GSM) and CDMA-based standards depending on the type of multiplexing used. It allows slow data communications but its primary focus is voice.

3G - Third Generation Wireless Technology

3G stands for the third generation of wireless communication technologies, which support broadband voice, data and multi-media communications over wireless networks. Main 3G standards include CDMA2000, WCDMA, UMTS, etc.

4G - Fourth Generation of Wireless Communications

4G is the name for the next generation of technology for high-speed wireless communications that is currently in research and development stage. 4G will be designed for new data services and interactive TV through mobile network.



AC - Alternating Current

Alternating Current

ADC - Analog-to-Digital Converter

Analog-to-Digital Converter (ADC, A/D or A to D) is an electronic device that converts continuous signals to discrete digital numbers. The reverse operation is performed by a digital-to-analog converter (DAC). An ideal ADC uniquely represents all analog inputs within a specified total input range by a limited number of digital output codes.

AIMS - Advanced Iterative Matrix Solvers

Advanced Iterative Matrix Solvers


An electronic device used to increase an electrical signal and output an enlarged reproduction of that signal without substantially altering the original signal. The device draws power from a source other than the input signal. The input and output signals may be voltage, current or both (power).

AMPS - Advanced Mobile Phone System

Advanced Mobile Phone System (AMPS) Service is the analogue mobile phone system standard, introduced in the Americas during the early 1980s. Though analogue is no longer considered advanced at all, the relatively seamless cellular switching technology AMPS introduced was what made the original mobile radio telephone practical, and was considered quite advanced at the time.

ASP - Application Service Provider

Application Service Provider

ATM - Asynchronous Transfer Mode

Asynchronous Transfer Mode


Additive White Gaussian Noise (AWGN) is the statistically random radio noise in the background of a communication channel. It is characterised by a wide frequency range.

BER - Bit Error Rate

BER – Bit Error Rate

BPSK - Binary Phase Shift Keying

Binary Phase Shift Keying (BPSK) is a type of phase modulation using 2 distinct carrier phases to signal, 0 or 1. BPSK is the simplest form of PSK. It uses two phases which are separated by 180° and so can also be termed 2-PSK. It does not particularly matter exactly where the constellation points are positioned, for example the real axis could be at 0° and 180°. This modulation is the most robust of all the PSKs since it takes serious distortion to make the demodulator reach an incorrect decision. It is, however, only able to modulate at 1bit/symbol and so is unsuitable for high data-rate applications.

Broadband Amplifier

An amplifier that amplifies electrical signals across a broad band of frequencies with little or no signal decay across that range of frequencies.

CCRR - Co-Channel Rejection Rate

Co–Channel Rejection Ratio

CDMA - Code Division Multiple Access

Code Division Multiple Access (CDMA) is a second generation (2G) cellular technology defined by Qualcomm in IS-95 and IS-2000. Other widely used multiple access techniques for cellular are Time Division Multiple Access (TDMA) and Frequency Division Multiple Access (FDMA). CDMA technologies are evolving into CDMA2000, the 3rd Generation solution based on IS-95, to meet the challenges.


Complementary Metal Oxide Semiconductor


Customer Premises Equipment


Channel Service Unit

Current Amplifier

An amplifier used to increase signal current, as opposed to increasing signal voltage or power.


Direct current


Distributed Communications System


Direct Digital Synthesis


Digital European Cordless Telephone

Distribution Amplifier

A device that accepts a single input signal and provides this same signal to multiple isolated outputs. In audio-visual systems, an RF power amplifier is used to feed television or radio signals to a number of different receivers as in an apartment, house or hotel.

DSP - Digital Signal Processor

Digital Signal Processor

Dual Amplifier

A dual amplifier allows two (or more) channels of measurement or control to be housed in a single enclosure.


Enhanced Data rates for GSM Evolution Enhanced Data Rates for Global Evolution (EDGE), also known as Enhanced GPRS (EGPRS), is a digital mobile phone technology which acts as a bolt-on enhancement to 2G and 2.5G General Packet Radio Service (GPRS) networks. This technology works in GSM networks. EDGE is a superset to GPRS and can function on any network that has GPRS deployed on it, provided the carrier implements the necessary upgrades. EDGE uses the same spectrum allocated for GSM900, GSM1800 and GSM1900 operations.

EIA - Electronic Industry Association

Electronic Industry Association (EIA) is a trade and standards organisation in the USA.

EM - Electromagnetic

EM – electromagnetic

EMC - Electromagnetic Compatibility

Electromagnetic Compatibility (EMC) is the ability of different items of electrical equipment to work together without suffering the effects of interference. Equipment should operate without interfering with broadcast and communications signals and be immune to normal levels of such signals. For a given environment, e.g. on the factory floor, EMC implies that equipment should not generate unacceptable levels of interference which affect the performance of other products designed to operate in an industrial environment. Equipment should have sufficient immunity to electrical interference so that the equipment continues to operate in an acceptable manner.

EMI - Electromagnetic Inteference

Electromagnetic Interference (EMI) is the interference by electromagnetic signals that can cause reduced data integrity and increased error rates on transmission channels.


Electrical Overstress


Electrostatic Discharge

FDD - Frequency Division Duplex

Frequency Division Duplex (FDD), used in cellular communication systems such as GSM, is a radio technology using a paired spectrum.


Field-Effect Transistor

FIR - Finite Impulse Response

Finite Impulse Response (FIR) is a technique used to characterise electrical circuits and networks in the time domain.

FSK - Frequency Shift Keying

Frequency Shift Keying (FSK) is a form of modulation using multiple carrier frequencies to carry digital information. The most common one is the two-frequency FSK system using two frequencies to carry the binary ones and zeros.


GaAs – Gallium Arsenide


GaN – Gallium Nitride

GFSK – Gaussian Filtered Frequency Shift Keying

Gaussian Filtered Frequency Shift Keying

GMSK - Gaussian Minimum Shift Keying

Gaussian Minimum Shift Keying (GMSK) is a modulation technique involving Gaussian filtering of the input data prior to its application to the phase modulator. This results in a narrowly occupied spectrum and better adjacent channel interference performance

GPIB - General Purpose Interface Bus

General Purpose Interface Bus


Global System for Mobile communications

GSM 1800

GSM 1800, also known as DCS 1800 or PCN, is a moble network working on a frequency of 1800 MHz. It is used in Europe, Asia-Pacific and Australia.

GSM 1900

GSM 1900, also known as PCS 1900, is a mobile network working on a frequency of 1900 MHz. It is used in the US and Canada and is scheduled for parts of Latin America and Africa.

GSM 900

GSM 900, or just GSM, is the world's most widely used digital network -- now operating in over 100 countries around the world, particularly in Europe and Asia Pacific.

GSM Plus

GSM plus is an enhanced version of Gobal System for Mobile communications (GSM) technology that will be developed to meet IMT-2000 capabilities. Global System for Mobile Communications (GSM), originally known as Groupe Special Mobile, is a digital cellular system defined by ETSI based on TDMA narrowband technology. GSM allows up to eight simultaneous communications on the same frequency. GSM is widely deployed in Europe and some Asian Countries, competing with CDMA which was developed by Qualcomm and deployed mainly in the US.


Global System for Mobile communications for Railway networks (GSM-R) uses standard base station and switching infrastructure to provide fast data transmission for railways. GPRS Support Node (GSN) is a network node which supports the use of GPRS in the GSM core network. All GSNs should have a Gn interface and support the GPRS tunnelling protocol. There are two key variants of the GSN: the GGSN and the SGSN.

HBT - Heterojunction Bipolar Transistor

Heterojunction Bipolar Transistor

HCI - Host Controller Interface

Host Controller Interface is a geosynchronous orbit that has the same orbital period as the sidereal rotation period of the Earth. It has a semi-major axis of 42,164 km.


High Data Rate


High Electron Mobility Transistor

HSCSD - High Speed Circuit Switched Data

High Speed Circuit Switched Data (HSCSD) is a circuit-linked technology for higher transmission speeds up to 57 Kbps, primarily in GSM systems.

I and Q

In–phase and quadrature

I/O - Input/Output

I/O – Input/Output

IAD - Integrated Access Device

Integrated Access Device

IEC - International Electrotechnical Commission

IEC – International Electrotechnical Commission

IF - Intermediate Frequency

Intermediate Frequency (IF) is a frequency to which a carrier frequency is shifted as an intermediate step in transmission or reception. Intermediate electromagnetic frequencies are generated by a superheterodyne radio receiver.

IM - Intermodulation


IMD - Intermodulation Distortion

Intermodulation Distortion

InP - Indium Phosphide

InP – Indium Phosphide

IQC - Incoming Quality Control

IQC – Incoming Quality Control


Interim Standard 95 (IS-95), is the first CDMA-based digital cellular standard pioneered by Qualcomm. The brand name for IS-95 is cdmaOne. IS-95 is also known as TIA-EIA-95. It is a 2G mobile telecommunications standard that uses CDMA, a multiple access scheme for digital radio to send voice, data and signalling data (such as a dialled telephone number) between mobile telephones and cell sites.

ISM - Industrial Scientific Medical

Industrial Scientific Medical

IT - Information Technology

IT – Information Technology

LDMOS - Laterally Diffused Metal Oxide Silicon

Laterally Diffused Metal Oxide Silicon

LMDS - Local Multiport Distribution System

Local Multipoint Distribution System (LMDS) is the broadband wireless technology used to deliver voice, data, Internet and video services in the 25-GHz and higher spectrum (depending on licencing). As a result of the propagation characteristics of signals in this frequency range, LMDS systems use a cellular-like network architecture. Services provided are fixed, not mobile. In the United States, 1.3 MHz of bandwidth (27.5 B 28.35 GHz, 29.1 B 29.25 GHz, 31.075 B 31.225 GHz, 31 B 31.075 GHz, and 31.225 B 31.3 GHz) has been allocated for LMDS to deliver broadband services in a point-to-point or point-to-multipoint configuration to residential and commercial customers.

LNA - Low Noise Amplifier

Low Noise Amplifier (LNA) is a receiving pre-amplifier with very low internal noise characteristics which is placed very near the antenna of a receiver to capture the C/N before it can be further degraded by noise in the receiving system.

LO - Local Oscillator

Local Oscillator


Low–Pass Filter

LTCC - Low Temperature Co-fired Ceramic

Low Temperature Co–fired Ceramic

MDS - Multipoint Distribution Systems

Multipoint Distribution Systems

MMDS - Multichannel Multipoint Distribution Service

Multichannel multipoint distribution service (MMDS), also known as wireless cable, is a wireless telecommunications technology used for general-purpose broadband networkings or, more commonly, as an alternative method of cable television programming reception. MMDS is usually used in sparsely populated rural areas, where laying cables is not economically viable. The MMDS band uses microwave frequencies from 2 GHz to 3 GHz in range. Reception of MMDS-delivered television signals is done with a special rooftop microwave antenna and a set-top box for the television receiving the signals. The receiver box is very similar in appearance to an analog cable television receiver box.

MMIC - Monolithic Microwave Integrated Circuit

Monolithic Microwave Integrated Circuit


MOSFET – Metal–Oxide Semiconductor Field–Effect Transistor

NRZ - Non Return to Zero

Non Return to Zero (NRZ) is a type of data stream where successive data pulses "ones" are continuous over several clock cycles without returning to the "zero" state between successive "ones".

NTC - Negative Temperature Co-efficient

Negative Temperature Co-efficient

OSS - Operation System Support

OSS – Operation System Support

PA - Power Amplifier

Power Amplifier (PA) is a device for taking a low or intermediate-level signal and significantly boosting its power level. A power amplifier is usually the final stage of amplification in a transmitter.

PC - Personal Computer

PC – Personal Computer

PCN - Personal Communications Network

Personal Communications Network (PCN) is a standard for digital mobile phone transmissions operating at a frequency of 1800 MHz (also referred to as GSM 1800). It is used in Europe and Asia Pacific.

PCS - Personal Communication Service

Personal Communication Service (PCS) describes a wide variety of two-way digital wireless service offerings in North America operating at 1900 MHz. PCS services include next generation wireless phone and communication services, wireless local loop, inexpensive walk-around communications service with lightweight, low-powered handsets, in-building cordless voice services for business, in-building wireless LAN service for business, enhanced paging service as well as wireless services integrated with wired networks. A Personal Communications System refers to the hardware and software that provide communications services.

PDA - Personal Digital Assistant

Personal Digital Assistant (PDA) is a small, handheld wireless device for transmitting pages, data messages, faxes and emails. It also acts as an electronic organiser, giving you access to schedules and contact lists. The term is often used interchangeably with PIM (Personal Information Manager). The 3Com PalmPilot is an example of a PDA or PIM.

PDC - Personal Digital Cellular

Personal Digital Cellular (PDC) is a TDMA-based 2G mobile phone standard developed and used exclusively in Japan. PDC uses a 25 kHz carrier, 3 time slots, pi/4-DQPSK modulation and low bit-rate 11.2 Kbps and 5.6 Kbps (half-rate) voice codecs. PDC is implemented in the 800 MHz (downlink 810-888 MHz, uplink 893-958 MHz), and 1.5 GHz (downlink 1477-1501 MHz, uplink 1429-1453 MHz) bands. The air interface is defined in RCR STD-27 and the core network MAP by JJ-70.10.

PLL - Phase Locked Loop

Phase Locked Loop (PLL) is a major component in the frequency synthesiser scheme. This device provides a wide, flexible range of internal frequency dividers which gives the designer the ability to create a synthesiser to match design requirements.

PSK - Phase Shift Keying

Phase Shift Keying (PSK) is a broad classification of modulation techniques where the information to be transmitted is contained in the phase of the carrier wave.

PSTN - Public Switched Telephone Network

Public Switched Telephone Network (PSTN) is the World's public circuit-switched telephone networks, providing commercial telephony services. Originally a network of fixed-line analog telephone systems, the PSTN is now almost entirely digital and includes mobile as well as fixed telephones.

PTFE – Polytetrafluoroethylene


QPSK - Quadrature Phase Shift Keying

Quadrature Phase Shift Keying (QPSK) is a digital modulation scheme that conveys data by changing, or modulating, the phase of a reference signal (the carrier wave). Sometimes known as quaternary or quadriphase PSK or 4-PSK, QPSK uses four points on the constellation diagram, equispaced around a circle. With four phases, QPSK can encode two bits per symbol, shown in the diagram with Gray coding to minimize the BER.

RF Power Amplifier

An RF Power Amplifier (PA) is defined as a final active stage of an RF Power electronic transmitting system. PA can be designed as a small MMIC used to transmit lower power such as cellular hand-sets and other portable applications, or a large rack-mounted PA used in high power RF systems such as DVB-T Broadcast, Cellular/PCS Wireless Infrastructure and Defence applications like Radars. Most of the Power Amplifiers designs are customised and designed for specific applications like HDTV, GSM, Radar, Point-to-Point Microwave or LTE. Matching specific main attributes of PA Frequency Range, Gain (dB), Gain Flatness (dB), Supply Voltage (VDC), P1dB (dBm) and Package of the amplifier with the end equipment is the main task of the RF Designer.

RFI - Radio Frequency Interference

Radio Frequency Interference (RFI) refers to the noise caused by other radio frequencies that interferes with information being transmitted across unshielded copper cable.

RFIC – Radio Frequency Integrated Circuit

Radio Frequency Integrated Circuit

RSSI - Relative Signal Strength Indicator

Relative Signal Strength Indicator (RSSI) is a measurement of radio signals at the point in which they are received and measured.

RTT – Radio Transmitter Technologies

RTT – Radio Transmitter Technologies

SD – Sigma Delta

SD – Sigma Delta

SDH – Synchronous Digital Hierarchy

SDH – Synchronous Digital Hierarchy

SFDR – Spurious-Free Dynamic Range

SFDR – Spurious-Free Dynamic Range

SMD – Short Message Delivery

SMD – Short Message Delivery

SMS - Short Message Service

Short Message Service (SMS) refers to the service that allows the transmission of short text messages among mobile devices such as cell phones, fax machines and BlackBerry devices. SMS was originally designed as part of GSM, but is now available on a wide range of networks, including 3G networks. There are two forms of SMS: Short Message Service - Point-to-Point (SMS-PP) and Short Message Service - Cell Broadcast (SMS-CB). The message length is 140 bytes. Larger contents (known as long SMS or concatenated SMS) can be sent segmentedly over multiple messages, in which case each message will start with a user data header (UDH) containing segmentation information.

SNR - Signal-to-Noise Ratio

Signal-to-noise Ratio (SNR) is the ratio of usable signal being transmitted to the undesired signal (noise). It is a measure of transmission quality. The ratio of good data (signal) to bad (noise) on a line is expressed in decibels (dB).

SONET – Synchronous Optical Network

SONET – Synchronous Optical Network

SPDT – Single–Pole Double–Throw

SPDT – Single–Pole Double–Throw

SSB - Single-sideband modulation

Single-sideband modulation (SSB) is a refinement of the technique of amplitude modulation designed to be more efficient in its use of electrical power and bandwidth. It is closely related to Vestigial Sideband Modulation (VSB). To produce an SSB signal, a filter removes one of the sidebands. More often, the carrier is reduced (suppressed) or removed entirely. Assuming both sidebands are symmetric, no information is lost in the process. What remains still contains the entire information content of the AM signal, using substantially less bandwidth and power, but cannot now be demodulated by a simple envelope detector.

SSPA – Solid State Power Amplifiers

SSPA – Solid State Power Amplifiers

TCP – Transmission Control Protocol

TCP – Transmission Control Protocol

TDD - Time Division Duplex

Time Division Duplexing (TDD) refers to a transmission scheme that allows an asymmetric flow for uplink and downlink transmission which is more suited to data transmission. In a Time Division Duplex system, a common carrier is shared between the uplink and downlink, the resource being switched in time. Users are allocated one or more timeslots for uplink and downlink transmission.

TDMA - Time Division Multiple Access

Time Division Multiple Access (TDMA) divides a radio frequency available to a network into time slots and then allocates slots to multiple calls. So one frequency can support multiple, simultaneous data channels, using bandwidth more efficiently than earlier technologies. Available in 800 MHz or 1900 MHz frequencies, TDMA is used by the GSM digital cellular system.

TETRA – Trans European Trunked Radio

TETRA – Trans European Trunked Radio

TIA - Telecommunications Industry Association

Telecommunications Industry Association (TIA) is one of the telecommunications standards setting bodies in the United States.

TTL – Transistor –Transistor Logic

TTL – Transistor –Transistor Logic

TXCO – Temperature–Compensated Crystal Oscillator

TXCO – Temperature–Compensated Crystal cscillator

UDP – User Datagram Protocol

UDP – User Datagram Protocol

UMTS - Universal Mobile Telecommunications System

Universal Mobile Telecommunications System (UMTS) is a 3G cellular network technology that uses WCDMA (Wideband Code Division Multiple Access) technologies. The transmission rates range from a theoretical 384K bit/sec for mobile phones to 2M bit/sec for stationary devices.

UTRA - UMTS Terrestrial Radio Access

UMTS Terrestrial Radio Access (UTRA) is a term used for UMTS radio access solutions and applied to W-CDMA and TD-CDMA.

VCO – Voltage-Controlled Oscillator

VCO – Voltage-Controlled Oscillator


Voltage–Controlled Crystal Oscillator

VOFDM – Vector Orthogonal Frequency Division Multiplexing

VOFDM – Vector Orthogonal Frequency Division Multiplexing


Very Small Aperture Terminal (Satellite Service)

WAP - Wireless Access Point

A wireless access point (WAP), also known as Access Point (AP), is a device that "connects" wireless communication devices together to create a wireless network. WAPs act as a central transmitter and receiver of WLAN radio signals. Access points used in home or small business networks are generally small, dedicated hardware devices featuring a built-in network adapter, antenna and radio transmitter. Access points support Wi-Fi wireless communication standards. Many WAPs can be connected together to create a larger network that allows "roaming".

WCDMA - Wideband-Code Division Multiple Access

Wideband Wideband-Code Division Multiple Access(W-CDMA or WCDMA), also known as UMTS in Europe, is a 3G standard for GSM in Europe, Japan and the United States. It is also the principal alternative being discussed in Asia. It supports very high-speed multimedia services such as full-motion video, Internet access and video conferencing. It uses one 5 MHz channel for both voice and data, offering data speeds of up to 2 Mbps.

WLAN - Wireless Local-Area Networks (Wireless LAN)

Wireless local-area networks (WLAN or wireless LAN) use radio waves to connect a user device to a LAN, which extends an existing wired local area network. WLAN provides Ethernet connections over the air and operates under the 802.11 family of specifications developed by the IEEE. WLANs are built by attaching a device called the access point (AP) to the edge of the wired network. Clients communicate with the AP using a wireless network adapter similar in function to a traditional Ethernet adapter. The WLAN technology is defined by the IEEE 802.11 family of specifications, namely, 802.11, 802.11a, 802.11b, 802.11g and 802.11n. All use the Ethernet protocol and CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance instead of CSMA/CD) for path sharing.