SSMB datasheet(37/39 Pages) ITT

37 / 39 page

141

RF Coaxial Connectors

Glossary of Terms

What do you mean, ‘‘Impedance’’?

In every job speciality there are certain words and

phrases used by the ‘‘insiders’’ which after a time

become almost a language unique to that

speciality. Radio frequency (RF) and microwave

technology is a typical example of that condition.

The following pages provide some explanations, in

an attempt to clarify some of the terms that are

commonly used by engineers and sales staff at

ITT Cannon.

The list is not comprehensive, but highlights many

of the expressions commonly used. Should you

have any comments or additions please contact

us. Feedback will be appreciated.

1.0/2.3

- A miniature connector in both 50 and 75 versions used for

communications and instrumentation. 75

now popular in

telecommunications.

1.6/5.6

- A 75

connector used extensively in telecommunication

systems.

Anti-cocking

- A mechanism to prevent a connector from mis-

aligning.

Attenuation

- Decrease in power due to resistance or mismatch in

transmission line.

Back Mounted

- When applied to a coaxial connector it is that

connector mounted from the rear of a panel with the fixing nut on the

outside.

Bandwidth

- Is the distance between two frequencies over which a RF

or microwave device is intended to work.

Between Series Adaptor

- An adaptor used to connect two different

generic types of connector.

Blind mate

- Connectors which may be mated when out of view owing

to their float mount facility.

BMA

- A blind mate connector capable of working to18 GHz; this range

is covered by MIL spec style BMA.

BMBTM

- A blind mate connector capable of working to 18 GHz. Not

compatible with BMA.

BNC

- Bayonet Nut Connector. Probably the most commonly used

coaxial connector in professional electronics.

Braid

- A weave of metal strands used as an electrical shield for an

insulated conductor or group of conductors.

BS9210

- The generic British Standard specification covering coaxial

connectors.

- British Telecom. Designation given to cable and connectors

specified by this telecom operator.

Bulkhead mount

- The type of connector fitted to a chassis using a

single cut-out hole.

Cable retention

- The mechanism that joins the connector to the

cable.

Cable retention force

- The axial force which a connector/cable join

can withstand.

Captive

- A component such as a contact which is held firmly in

position.

Characteristic Impedance

- That impedance at which the

transmission line is intended to work. A change from the characteristic

impedance along its length will cause mismatch and loss of power.

Clamp

- The holding of a cable by use of a screw thread action.

Closed entry contact

- A female contact which is designed to prevent

insertion of a contact larger than that specified.

CMM

- Self-aligning microminiature blind mate connectors with non-

butting interface

Coaxial Cable

- A transmission line where the one conductor is

concentric inside another; often abbreviated to ‘coax’.

Coaxial termination

- A resistive element used to end a coaxial line in

its characteristic impedance.

Coaxial terminator

- A device for terminating coaxial cable to a PCB or

bulkhead (purely a mechanical device and should not be confused

with coaxial termination)

Coaxitube

- Trade name for Precision Tube Inc.’s semi-rigid cable.

Conhex

- Trade name covering SMB and SMC, both in 50 Ohm and 75

Ohm impedances (Discontinued).

Connector durability

- The number of times a connector can be

physically mated and still maintain its specified performance.

Contact resistance

- The measurement of the DC electrical resistance

between a pair of mated contacts. Usually specified as being

measured after a given number of mating cycles.

Corona

- A discharge of electricity caused by the ionisation of the air

around a conductor just prior to total breakdown or flashover.

Crimp:

- The action of distorting a metal tube to give intimate contact

with a conductor; a good crimp should be gas tight and not be

impacted by environmental change.

Crimp dies

- The tool inserts which determine the shape of the

distortion to create a consistently good crimp.

Crimp tool

- The tool which holds crimp dies to apply the necessary

force.

Cross talk

- The amount of signal which may be transferred from one

signal carrying line to an adjacent line.

Cut off frequency

- The frequency at which the loss exceeds a

predetermined level.

- Abbreviation for Decibel.

DDF

- Digital Distribution Frame. Used in telecommunication

exchanges.

Decibel (dB)

- A unit of measurement of RF power loss.

Dielectric

- The insulating medium which holds the center conductor

concentric within the connector or cable.

Dielectric constant

- The electrical value of the dielectric which

determines the impedance in cables or connectors with constant

diameters.

Dielectric withstanding voltage

- The maximum voltage that a

dielectric material can withstand without failure.

Direct solder

- A common method of terminating connectors to

semi-rigid cable by soldering the cable jacket to the connector.

Discontinuity

- A dramatic change in characteristic impedance which

gives rise to a reflected wave.

Dissipation

- The unused or lost energy in a system e.g. heat.

Distortion

- An unwanted change in a signal wave form.

Dummy load

- A device connected to the end of a transmission line to

absorb transmitted power and prevent reflected energy.

Dust cap

- A mechanical device attached to the mating face of an

unmated connector to prevent ingress of contaminants and provide

protection against mechanical damage.

Duty factor

- The way of deriving the average power.

Electromagnetic compatibility (EMC)

- The ability of a device to

operate within its intended environment without being effected by or

generating electromagnetic interference (EMI).

EMI

- Electro-magnetic interference (created by the field force

surrounding a transmission line carrying RF power)

Engagement and separation forces

- The forces required to mate and

unmate a pair of connectors. The forces are usually specified as a max

& min for each action.

Environmentally sealed

- A connector that is provided with seals or

other devices to prevent ingress of dust, moisture or other

contaminants whilst mated which might impair performance.

Flexible cable

- A coaxial cable where the outer conductor is flexible

(usually braided).

Flexit

- A flexible cable from ITT Cannon which has similar properties

to semi-rigid.

Float mount

- A mounting mechanism that allows the connector to

move enabling compensation for axial and radial misalignment.

Fret corrosion

- The increase in speed of oxidation created by two

materials in intimate contact and subject to vibration.

Gang mounted

- The mounting of multiple connectors on a single

panel.

Gigahertz (GHz)

- A measure of frequency representing 1 billion Hertz

(cycles per second).

HDC

- High Density Connector. A variant of SMZ connector.

Hermetic seal

- The fixed half of a connector which is sealed against

the passage of gas from one side of a bulkhead to another in the mated

or unmated condition.

Impedance

- See ‘‘Characteristic impedance’’.

In-series adaptor

- An adaptor which enables the connection of two

connectors of the same generic type.

Insertion loss

- The loss of power due to a particular component in a

transmission line (e.g. cable)

Insulation resistance

- The electrical resistance between two

conductors separated by an insulating medium.

Inter modulation

- The mixing of two or more frequencies which are

not intended to mix.

Interface

- The two surfaces of a connector which come into intimate

contact when the two halves are mated.

Inter-series adaptor

- See ‘‘Between Series Adaptor’’.

Isolation

- The measure of interaction between two or more

transmission lines.

Jack

- One half of a mating pair of connectors. The jack interface

normally goes inside the plug interface.

Line stretcher

- Alternative name for Phase Adjuster.

MCX

- A miniature connector with a size between the SMB & SSMB.

Mean power

- The mean value of the rate at which energy is

transmitted from one place to another.

Micro strip

- A Transmission line consisting of a flat conductor on a

dielectric above a single ground plane. (The ground plane is frequently

a metalised face of the dielectric).

SSMB 数据表(PDF) 37 Page - ITT Industries

SSMB 数据表(HTML) 37 Page - ITT Industries

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39

数据表下载