Abbreviation |
Expanded Words |
Comments |

AC |
Alternating Current | |

ADC |
Analog to Digital Converter | |

AF |
Audio Frequency | Low frequency signals usually below 100 kHz. |

AGC |
Automatic Gain Control | |

ALC |
Automatic Level Control | |

AM |
Amplitude Modulation | |

Amp |
Amplifier | |

ASK |
Amplitude Shift Keying | |

BJT |
Bipolar Junction Transistor | |

BPF |
Band Pass Filter | |

CMOS |
Complimentary Metal Oxide Silicon (IC) | |

DAC |
Digital to Analog Converter | |

DBM |
Double Balanced Mixer | |

DC |
Direct Current | |

Direct Conversion | Refers to a receiver or transmitter topology with I and Q base-band processing | |

DFM |
Design For Manufacture | A collection of philosophies intended to streamline the manufacture of products and reduce overall cost |

DFT |
Discrete Fourier Transform | Fourier Transform applied to a time sampled system |

DRFSA |
Direct RF Signal Acquisition | Receiver topology based on the use of a high speed ADC used to digitize RF signals |

DRFSS |
Direct RF Signal Synthesis | Transmitter topology based on the use of a high speed DAC used to generate RF signals |

DSP |
Digital Signal Processing | |

FET |
Field Effect Transistor | Three terminal voltage operated amplifying device |

FFT |
Fast Fourier Transform | Computationally efficient physical implementation of a DFT |

FIR |
Finite Impulse Response (filter) | |

FM |
||

FPGA |
Field Programmable Gate Array | Integrated Circuit "sea of gates" - configurable by software to form arbitrary digital functions |

FSK |
Frequency Shift Keying | |

FT |
Fourier Transform | Converts time domain representation to a frequency domain representation |

GASFET |
Gallium Arsenide FET | Microwave version of a FET using Gallium Arsenide (not silicon) |

HPF |
High Pass Filter | |

IC |
Integrated Circuit | Semiconductor "Chip" containing active and passive devices to form a circuit |

IDFT |
Inverse DFT | Inverse Fourier Transform applied to a frequency sampled system |

I/F |
Interface | |

IFFT |
Inverse FFT | Computationally efficient physical implementation of an IDFT |

IF |
Intermediate Frequency | Output signal following frequency conversion (usually below RF or LO frequencies) |

IFT |
Inverse Fourier Transform | Converts time domain representation to a frequency domain representation |

IGBT |
Insulated Gate Bipolar Transistor | Composite high power device based on a MOSFET + JFET + Bipolar structure |

IIR |
Infinite Impulse Response (filter) | |

IQ |
In Phase & Quadrature Phase | Complex signal representation V_{iq} { t
} = V_{i}{ t } + j · V_{q}{ t } |

JFET |
Junction FET | Depletion mode P-gate, N-drain-source or N-gate, P-drain-source |

LASER |
Light Amplification by Stimulated Emission of Radiation | Used to create a "coherent" light source (i.e. narrow spectral bandwidth) based on multiple internal reflections through an externally powered medium that increases optical energy energy |

LC |
Inductor-Capacitor | Series or Parallel tuned circuit reference |

LCR |
Inductor-Capacitor-Resistor | Series or Parallel tuned circuit reference with resistive loss |

LDO |
Low Drop Out (regulator) | Linear regulator with low differential input-output voltage (ΔV) requirement (good ones have ΔV < 0.2 Volts) |

LDR |
Light Dependent Resistor | Cadmium Sulphide or Cadmium Selenium based optical device with light dependent resistance. Has a similar optical response to the human eye |

LED |
Light Emitting Diode | Diode that produces moderate bandwidth light output from a DC power input. Used as a low cost indicator or torch bulb substitute. Versions are available from infrared to ultra violet |

LPF |
Low Pass Filter | |

MOSFET |
Metal Oxide Silicon FET | FET using an insulating oxide layer under a metal date |

MUSCAF |
Multiple User Software Configurable Arbitrary Format | Receiver or Transmitter architecture using DSP technology with flexible functionality |

NN |
Neural Network | |

NPN |
N-P-N | |

OCXO |
Oven Controlled XTAL (Crystal) Oscillator | Medium cost versions offer ±0.01 to ±0.1 ppm stability, expensive versions ca achieve ±0.001 ppm |

OFDM |
Orthogonal Frequency Division Multiplex/Modulation | |

OpAmp |
Operational Amplifier | |

PC |
Personal Computer | |

PCB |
Printed Circuit Board | |

PIN |
P-Intrinsic-N Type | P-N junction with intermediate non doped semiconductor |

PN |
P-N Type | |

PNP |
P-N-P Type | P-Type semiconductor has excess of +holes, N-Type has excess -electrons |

PSK |
Phase Shift Keying | |

PUT |
Programmable Unijunction Transistor | |

QAM |
Quadrature Amplitude Modulation | |

RC |
Resistor-Capacitor | Simple series, parallel or 2-port filter combination |

RF |
Radio Frequency | Generic term for systems with frequency dependant parasitic contributions |

SCR |
Silicon Controlled Rectifier | |

SiC |
Silicon Carbide | |

SiGe |
Silicon Germanium | |

SETI |
Search For Extra Terrestrial Intelligence | |

TCXO |
Temperature Compensated XTAL (Crystal) Oscillator | Temperature stability of 2 ppm over a wide temperature range is typical |

TL |
Transmission Line | |

TRF |
Tuned Radio Frequency | Early receiver approach based on cascaded RF amplification prior to signal detection |

TRIAC |
? | |

TTL |
Transistor-Transistor Logic | |

UFO |
Unidentified Flying Object | Any object regardless of origin |

UJT |
Unijunction Transistor | |

USB |
Universal Serial Bus | Trendy interface from a device to a PC |

Varicap |
Variable Capacitance (diode) | |

VCO |
Voltage Controlled Oscillator | Variable frequency oscillator controlled with a Varicap diode |

XTAL |
Crystal | |

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**© Ian R Scott 2007 - 2008**