| e0 | vacuum permittivity |
| er | relative dielectric constant |
| h | efficiency |
| l | wavelength |
| m | mobility |
| v | electron drift velocity |
| vsat | saturated electron velocity |
| t | time or lifetime |
| fb | barrier potential |
| fm | metal work function |
| c | electron affinity |
| 2DEG | two-dimensional electron gas |
| A | emitterbase junction or diode area; proportional multiplier |
| a | physical channel depth |
| ADC | analog-to-digital converter |
| Al | aluminum |
| As | arsenic |
| Au | gold |
| Be | beryllium |
| BER | bit error rate |
| BJT | bipolar junction transistor |
| b(x) | effective FET channel depth |
| C | carbon |
| CAD | computer aided design |
| CAE | computer aided engineering |
| CCS | collector-substrate capacitance |
| CDC | drain-channel capacitance |
| CF | total forward biased junction capacitance |
| Cj | junction capacitance; depletion region capacitance |
| CMOS | complimentary metal oxide semiconductor (transistor) |
| Cr | chromium |
| CTE | coefficient of thermal expansion |
| Cv | capacitance of insulating region |
| dB | decibels (dB = 10 log[power]) |
| DBS | direct broadcast satellite |
| Dn | electron diffusivity |
| DNP | distance neutral point |
| Dp | hole diffusivity |
| Ea | activation energy |
| E-B | emitterbase |
| Ec | conduction band energy |
| EDM | empirical device model |
| Ef | Fermi energy |
| Eg | bandgap energy |
| Em | breakdown electric field |
| EOS | electrical overstress |
| ESD | electrostatic discharge |
| Ev | valance band energy |
| eV | electron volt |
| fc | forward current cutoff frequency |
| fcc | face centered cubic |
| FEM | finite element method |
| FET | field effect transistor |
| FIT | failure in time (1 failure/1 ´ 109 device h) |
| fmax | maximum frequency of oscillation |
| ft | cutoff frequency or frequency where unilateral power gain equals one |
| f(t) | failure rate |
| g | gram |
| GaAs | gallium arsenide |
| GCR | galactic cosmic rays |
| Ge | germanium |
| GEO | geostationary orbit |
| gm | transconductance |
| GPS | Global Positioning System |
| h | hour |
| HBT | heterojunction bipolar transistor |
| HDI | high density interconnect |
| HEMT | high-electron mobility transistor |
| hfe | current gain |
| I | current |
| ID | drain current |
| IDSS | drain-source saturation current |
| IF | intermediate frequency |
| IMPATT | impact ionization avalanche transit time (diode) |
| In | electron injection current |
| In | Indium |
| IR | infrared |
| J | current density |
| JFET | junction field effect transistor |
| J0 | constant depending on doping concentration |
| K | Kelvin |
| k | Boltzman's constant |
| Ka | frequency band (26.540 GHz) |
| Ku | frequency band |
| L | length |
| LEC | Liquid Encapsulated Czochralski |
| LEO | low Earth orbit |
| LET | linear energy transfer |
| LNA | low-noise amplifier |
| LO | local oscillator |
| LTCC | low-temperature cofired ceramic |
| MBE | molecular beam epitaxy |
| MESFET | metal-semiconductor field effect transistor |
| MIC | microwave integrated circuit |
| MIM | metal-insulator-metal (capacitor) |
| MMIC | monolithic microwave integrated circuit |
| MOCVD | metal-organic chemical vapor deposition |
| MODFET | modulation doped field effect transistor |
| MTBF | mean time between failure |
| MTTF | mean time to failure |
| n | ideality factor |
| NA | acceptor impurity density |
| NB | base doping concentration |
| ND | donor impurity density |
| Nd | donor doping concentration |
| NE | emitter doping concentration |
| NF | noise figure |
| Ni | nickel |
| NPN | n-typep-typen-type (transistor) |
| n(x) | electron density |
| P(s) | probability of success |
| PBM | physically based model |
| PCS | personal communication system |
| Pd | palladium |
| PHEMT | pseudomorphic high-electron mobility transistor |
| PIN | p-typeinsulatorn-type (diode) |
| PIND | particle impact noise detection |
| PIX | polyimide die overcoat |
| PM | parametric monitor |
| PNP | p-typen-typep-type (transistor) |
| Pout | output power |
| Pt | platinum |
| Q | quality factor |
| q | charge of an electron |
| Qc | critical charge |
| QML | Qualified Manufacturers Listing |
| r | rate of a process |
| Rb | base resistance |
| RD | drain resistance |
| RDS | channel resistance between drain and source |
| RF | radio frequency (typically refers to highest frequency in the circuit) |
| RF | total forward biased series resistance |
| RHA | radiation hardness assurance |
| RIE | reactive ion etch |
| Rj | junction resistance |
| Rohm | ohmic contact resistance |
| RS | source resistance |
| R(t) | reliability-the probability of a component surviving to time t |
| RTG | radioisotopic thermoelectric generator |
| Rv | resistance of insulating region |
| SAA | South Atlantic Anomaly |
| SCR | silicon-controlled rectifier |
| SEB | single event burnout |
| SEC | standard evaluation circuit |
| SEE | single event effect |
| SEGR | single event gate rupture |
| SEL | single event latchup |
| SEM | scanning electron microscope |
| SEU | single event upset |
| Si | silicon |
| SOI | silicon on insulator |
| SOS | silicon on sapphire |
| SPC | statistical process control |
| T | absolute temperature in Kelvin |
| t | time or carrier transit time |
| TCV | technology characterization vehicle |
| TEGFET | two-dimensional electron gas field effect transistor |
| TID | total ionizing dose |
| TRB | Technology Review Board |
| V | voltage |
| Va | early voltage |
| VBE | baseemitter voltage |
| Vbi | built-in voltage |
| VCF | potential between conduction band and Fermi level |
| VCO | voltage-controlled oscillators |
| VD | drain bias voltage |
| VDS | potential between drain and source |
| VG | gate bias voltage |
| VLSI | very large scale integration |
| Vp | pinch-off voltage |
| VT | thermal potential |
| W | width |
| W | frequency band (75110 GHz); tungsten |
| WLAN | Wireless Local Area Network |
| X | frequency band (812 GHz) |
| Z | gate width; width of channel |