Appendix 2Classifi cation of Electronic Components
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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
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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