Appendix 2Classifi cation of Electronic Components

70

Electronic components are passive components that are used for electronic circuits. In a limited sense, these do not include sound-, light-, or mechanical-related components or electromechanical components such as a switch or connector. When electronic components are sorted according to their usage, they can be divided into “resistive components” and “others (reactive components)” (Table A2-1). The latter components are lossless, so they are used in order to control signal or electric power. Components that are used for analog high-frequency circuits such as balun, coupler, circulator and so on are designed to handle a single frequency and to basically control signal fl ow. On the other hand, components that are used for digital circuits such as capacitors, inductors, and three-terminal fi lters with combinations of capacitors and inductors are designed to handle multiple frequencies and are used as fi lters. Of course, capacitors and inductors have multiple purposes and can be used for other situations. For more information on the functions and usages of electronic components, refer to Table A2-2."EMC components" is a general term for electronic components used to control EMC. These include the kind of fi lter and varistor (this can also be considered a fi lter for voltage) shown in Table A2-1. Therefore, EMC components do not refer only to special components. There is no clear distinction between inductors and beads. However, a bead is basically a loss in the high frequency range and is commonly used because their loss is effective at preventing EMC (energy can be absorbed). On the other hand, an inductor is used in the relatively low frequency range where high inductance is needed.Chip components (SMD components) do not include leads and are connected directly to substrates. Usually, their size is described using a 4-digit number. For example, "1005" indicates a component

that is 1.0mm length × 0.5mm width.Electrical characteristics for electronic components can be evaluated using impedance and / or S-parameters. Impedance applies to two-terminal components. It is also possible to use impedance for the characteristics of multi-terminal components if those terminals can be combined to form a two-terminal component, e.g. the common mode fi lter (CMF) and transformer. These characteristics can be described using several kinds of impedance by changing connections. Components that require a GND are characterized by S-parameter because impedance is diffi cult to use. If a component that is usually evaluated using impedance is attached to a GND, evaluation by using S-parameters is possible.

Table A2-1 Representative electronic components

Category Electronic component

Resistive componentResistorThermistorVaristor

Reactive component

Control signals

Transmission linePower splitterBalunCoupler, Isolator, Circulator

Filter

CapacitorInductive components Inductor, Bead Transformer, Common mode fi lterThree-terminal fi lter

Classifi cation of Electronic Components

71

NTC

Balun

Table A2-2 Functions and usages of various electronic components

Electronic component Exterior Type Function Usage

ResistorThick fi lm (Cermet) Thin fi lm (Metallic fi lm)

Z=RDivides voltage and current /Limits the current / Detection / Termination (Load) / Filter

NTC Thermistor Ceramic Z=R(T) Temperature measurement

PTC ThermistorPlastic / Ceramic

Z=R(T) Over current prevention (Fuse) / Heater

VaristorZnO TypeSrTiO3 Type

Z=R(V) Over voltage prevention

CapacitorCeramic[Hε,Lε] Electrolytic type[Al,Ta], Film

Q=CVZ=1/jωC

Bypass (Decoupling) / Smoothing / Coupling / Filter (RC,LC) / Time constant /Matching / Phase compensation

InductorAir core, Ferrite [Mn,Ni]Metallic

Z=jωL Choke / Decoupling / Filter / Matching

Beads Ferrite Z=R(f)+jX Noise control

TransformerFerritePiezoelectric

➞

DC isolation / Common mode rejection /Balance-Unbalance conversion / Change polarity /Up- or Down-convert voltage / Transform impedance

CMFWinding, Thin fi lmMulti-layer

Scc21=Scc21(f) Common mode noise control

Filter, DuplexerLC, PiezoelectricDielectric

Sij=Sij(f) Signal fi ltering

Power splitter - S =0 α βα 0 0β 0 0

Split and / or combine signal

Balun - S =0 α -αα 0 0-α 0 0

Balance-Unbalance conversion

Coupler - S = 0 tUU 0

Signal monitor / Separate incidence and refl ection signal

Isolator - S =0α 0

0 Unidirectional(Protect for refl ection signal), Mismatch relief

Circulator - S =0 αα 0 00 α 0

0Antenna sharing, Isolator, Branch signal