Electronic Engineering Glossary Terms

Backbone. A high traffic connectivity portion of any communications network. In packet-switched networks, a primary forward direction path traced sequentially through two or more major relay or switching stations. In packet-switched networks, a backbone consists primarily of switches and inter-switch trunks. Also refer to the dictionary of Network Topologies.

Background Noise. The total system noise in the absence of a signal [information transmission].

Backplane. A circuit card that contains two or more connectors of the same type which are connected together via discrete wires or copper traces on the circuit board to form an interface bus, which allows the boards to communicate with each other. Backplanes.

19 Slot VME Backplane

Back Resistance. The larger resistance value observed when you are checking the resistance of a semiconductor.

Back Shell. The rear portion of a connector.
Read more regarding Back Shell Definition.

Bad Block / Bad Sector. An area on a hard disk drive that is damaged or detected as unreliable.

Balance. In electrical circuits and networks, to adjust the impedance to achieve specific objectives, such as to reach specified return loss objectives at a hybrid junction of two-wire and four-wire circuits.

Balanced Amplifier. An amplifier with two identical branches connected to operate in opposite phase, with their input and outputs connections balanced to ground. A Push-Pull Amplifier. An amplifier having one output is considered balanced when the quiescent DC output voltage is reduced to zero or a specified level. An amplifier having two outputs is considered balanced when the difference between the quiescent DC output voltages is reduced to zero or a specified level.

Balanced Attenuator. An attenuator which uses resistance elements in both sides of the line. Refer to the Resistor Attenuator page for a schematic of many of the different types of balanced attenuators.

Balanced Bridge. A bridge circuit adjusted to produce a zero output.

Balanced Circuit. See Balanced Line.

Balanced Code. In PCM systems, a code constructed so that the frequency spectrum resulting from the transmission of any code word has no DC component. A code that has a finite digital sum variation [PCM]. A number of additional terms are related, use the search bar, below right, to find the correct definition.

Balanced Line. A cable or circuit having two identical conductors with the same electromagnetic characteristics in relation to other conductors and to ground, as in a pair of conductors. A twisted pair line

A transmission line consisting of two conductors in the presence of ground, capable of being operated so that when the voltages of the two conductors at all transverse planes are equal in magnitude and opposite in polarity with respect to ground, the currents in the two conductors are equal in magnitude and opposite in direction. Also refer to the Detailed Twisted-Pair definition

Balanced Mixer. A circuit or device that generates the sum and difference frequencies of two input signals. RF Mixer Manufacturers

Balanced Phase Detector. A circuit that controls the oscillator frequency. A related topic includes; RF Phase Detector Manufacturers. Also refer to Automatic Frequency Control [AFC].

Ballast. A device or component used to stabilize current flow, as in a Ballast Resistor.

Ballast Resistor. A resistor used to compensate for fluctuations in an AC power line. A resistor connected in series to absorb small changes in applied voltage to stabilize the current.

Balun. An acronym for Balanced/Unbalanced. A device used to couple a balanced system to an un-balanced system. Read more Balun Definition. A balancing transformer. Also see RF Transformer Manufacturers.

Banana Jack. A type of female connector or receptacle that accepts a Banana plug. The Banana Jack may be a male on one end and a female on the other end, or a completely different style connector. Read more on Banana Jack Definition.

BNC to Banana Plug

Banana Plug. A connector with the male-end using a Banana shaped, spring metal tip, providing a compression fit into a banana jack.

Band-Elimination Filter. Same meaning as a Band-Reject Filter.

BandGap Reference. A type of voltage reference.

Bandpass Amplifier. An amplifier stage design to pass a range of frequencies. Refer to an Active Band-Pass Filter using an Op-Amp.

Bandpass Filter. A filter that allows a narrow band of frequencies to pass through the circuit. Rejects or attenuates frequencies that are either higher or lower than the desired band of frequencies. A filter that ideally passes all frequencies between two non-zero finite limits and bars all frequencies not within the limits. The cutoff frequencies are normally taken to be the 3-dB points.

Band-Reject Filter. A tuned circuit that does not pass a specified band of frequencies. Refer to the entry on Passive Filters. A filter that attenuates, usually to very low levels, all frequencies between two nonzero, finite limits and passes all frequencies not within the limits.

Band-Stop Filter. Same as a Band-reject Filter.

Bandwidth. The width of a communication channel, measured as frequency. The difference between the highest usable frequency of a device (upper frequency limit) and the lowest usable frequency of the device (lower frequency limit) - measured at the half-power points. The difference between the limiting frequencies within which performance of a device, in respect to some characteristic, falls within specified limits. The difference between the limiting frequencies of a continuous frequency band. The capacity of a telecom line to carry signals. The necessary bandwidth is the amount of spectrum required to transmit the signal without distortion or loss of information.

Bank. A number of devices of the same kind.

Bare Conductor. A conductor not covered with insulating material.

Barretter. A type of bolometer characterized by an increase in resistance as the dissipated power rises. A Thermistor.

Base. A reference value. A number that is multiplied by itself as many times as indicated by an exponent. Same as radix. The region between the emitter and collector of a transistor that receives minority carriers injected from the emitter. The element in a transistor that controls the flow of current carriers. The element that corresponds to the control grid of an electron tube.

Transistor Base

Base-Injection Modulator. Similar to a vacuum tube control-grid modulator. The gain of a transistor is varied by changing the bias on its base. See Base-Injection AM Modulator for a description.

Basic. Beginner's All-purpose Symbolic Instruction Code, a non-graphical programming language. Also refer to a short example of HP Basic.

Bass. Sounds in the lower end of the audio frequency range.

Bass Control. A passive circuit used to attenuate frequencies in the higher audio ranges. Refer to Base Control Schematic.