The 3 dB rule provides a means to estimate relative power values. A 3 dB gain indicates that power increases to twice the power (a multiple of 2). A 3 dB loss indicates that power decreases to half the power (a multiple of 1/2). A system with 40 watts of input power and a 6 dB insertion loss will have only 10†watts of output power (a multiple of 1/2 for each 3 dB loss, or 1/4 of 40 watts).

A fitting that supplies a passage between two sets of equipment when they cannot be directly interconnected.

Analog-to-Digital Converter (ADC, A/D or A to D) is an electronic device that converts continuous signals to discrete digital numbers. The reverse operation is performed by a digital-to-analog converter (DAC). ADC can uniquely represent all analog input values within a specified total input range by a limited number of digital output codes. Refer also to DAC.

Automatic Level Control (ALC)

An Analog system uses an analog transmission method to send voice, video and data-using analog signals, such as electricity or sound waves, that are continuously variable rather than discreet units as in digital transmissions. Mobile analog systems include AMPS, NMT and ETACS.

Analog Transmission refers to signals propagated through the medium as continuously varying electromagnetic waves.

The AutoCal VNA calibration method uses an external calibrator, such as the Anritsu 36585. The 36585 AutoCal module provides an automatic system for fast, repeatable high-quality calibrations of a VNA. The AutoCal module is inserted between the VNA test ports to perform the calibration. A serial to USB converter (Anritsu part number 2000-1809-R USB to Serial adapter) must be employed to enable communication between the autocal unit and the VNA.

Average power is the peak power averaged over time and is usually applied to pulsed systems where the carrier power is switched on and off.

Band, in telecommunication, refers to the following definitions: 1. The range of frequencies between two defined limits which are used for a specific purpose. 2. One of the geopolitical boundaries established to define a WATS (wide-area telephone service) serving area.

A Band Pass Filter is a radio wave filter with a specific range of frequencies in which it is designed to pass. It rejects frequencies outside the pass-band range. A resistor-inductor-capacitor circuit is an example of a Band Pass Filter.

Bandwidth usually identifies the capacity of a circuit or amount of data that can be sent through a given circuit. It may be user-specified in a PVC. It is an indication of the amount of data that is passing over a medium. Also, bandwidth is the portion of the frequency spectrum required to transmit desired information. Each radio channel has a center frequency and additional frequencies above and below this carrier frequency which is used to carry the transmitted information. The range of frequencies from the lowest to the highest used is called the bandwidth.

Broadband refers to telecommunication that provides multiple channels of data over a single communications medium, typically using some form of frequency or wave division multiplexing. It is a service or system requiring transmission channels capable of supporting rates greater than the Integrated Services Digital Network (ISDN) primary rate.

When making measurements, the instrument must be calibrated in order to remove residual errors due to measurement setup conditions. Anritsu recommends performing the calibration under the same conditions as the measurement: temperature, frequency, number of points, source power, and IFBW. Calibrations standards with known reflection coefficients are used to calculate the correction factors. The calibration must be conducted using the appropriate standards at the open end of any test port cables and adapters that are connected to the instrument. This ensures that the match, phase length, and loss of these cables and adapters are all accounted for. For optimal performance, high quality phase-stable cables and precision adapters must be used.

A Command Unit is a complete command that is formatted with parameters and terminators.

Configuration Commands are commands that are issued to an instrument and that change a specific instrument configuration.

Decibel or deciBel (dB) is a logarithmic ratio of the difference between two values (a logarithm ratio is equal to 10 times). dB is a unit for measuring relative power ratios in terms of gain or loss. The units of dB are expressed in terms of the logarithm to base 10 of a ratio and typically are expressed in watts. For example, a -3 dB loss indicates a 50% loss in power; a +3 dB reading is a doubling of power; 10 dB indicates an increase (or a loss) by a factor of 10; 20 dB indicates an increase (or a loss) of a factor of 100; 30 dB indicates an increase (or a loss) by a factor of 1000. Common values of dB expressed in ratios: 0 dB = 1:1, 10 dB = 10:1, 20 dB = 100:1, 30 dB = 1000:1, -30 dB = 0.001:1 [or (1/1000):1].

Decibels referenced to the carrier (dBc) is a technique for expressing a power measurement in logarithmic form using the carrier power as a reference. The units are used to describe how far down signals and noise are relative to a known signal. Typical use of this term is to describe spurious signals and noise compared to a desired transmit signal.

dBm is an absolute measurement of power relative to 1 milliwatt. In other words, dBm is a decibel value referenced to a milliWatt (dBm). This is a technique for expressing a power measurement in logarithmic form using 1 mW as a reference. dBm is a decibel ratio (log 10) of Watts (W) to one milliwatt (1mW). dBm, therefore, represents absolute power. Examples are: 0 dBm = 1.0 milliwatt, 10 dBm = 10 milliwatt, 30 dBm = 1000 milliwatt = 1 watt.

An Eye diagram (or eye-pattern diagram) is a superposition of segments of a received PAM signal that is displayed on an oscilloscope or similar instrument. The eye diagram is used to assess impairments in the radio channel.

Intermediate Frequency (IF) is a frequency to which a carrier frequency is shifted as an intermediate step in transmission or reception. An intermediate electromagnetic frequency is generated by a superheterodyne radio receiver.

VNA calibration media: Coaxial, Non-dispersive, Microstrip, Waveguide

Something may be described as linear if the characteristic is approximately but not exactly a straight line; and linearity may be valid only within a certain operating region.

VNA calibration method: Line-Reflect-Line

VNA calibration method: Line-Reflect-Match

The purpose of measurement is to provide information about a quantity of interest ñ a measurand. No measurement is exact. When a quantity is measured, the outcome depends on the measuring system, the measurement procedure, the skill of the operator, the environment, and other effects. Even if the quantity were to be measured several times, in the same way and in the same circumstances, a different measured value would in general be obtained each time, assuming the measuring system has sufficient resolution to distinguish between the values.

Multiline Through-Reflect-Line (mTRL)

Resolution Bandwidth (RBW) With spectrum analyzers, a narrow band filter is swept across a frequency span to create the spectrum display. The filter bandwidth (RBW) determines the frequency resolution across the frequency axis.

Return loss is a measure of how well devices or lines are matched. A match is good if the return loss is high. A high return loss is desirable and results in a lower insertion loss. return loss is the loss of power in the signal returned/reflected by a discontinuity in a transmission line or optical fiber.

Return loss is a measure of how well devices or lines are matched. A match is good if the return loss is high. A high return loss is desirable and results in a lower insertion loss. return loss is the loss of power in the signal returned/reflected by a discontinuity in a transmission line or optical fiber.

Is the square root of the arithmetic mean of the squares of the values, or the square of the function that defines the continuous waveform. Waveforms made by summing known simple waveforms have an RMS that is the root of the sum of squares of the component RMS values. Because of their usefulness in carrying out power calculations, listed voltages for power outlets (e.g., 120 V in the USA, or 230 V in Europe) are almost always quoted in RMS values, and not peak values.

The SmartCal VNA calibration method uses an external calibrator, such as the Anritsu MN252x8x, MN254x8x. The SmartCal module provides an automatic system for fast, repeatable high-quality calibrations of a VNA. The SmartCal module is inserted between the VNA test ports to perform the calibration. Connect the SmartCal to the VNA or control computer with the included USB A/Micro-B latch cable.

Generically, an .sNp file is in standard microwave simulator text format and is similar to the .txt file. The SnP files setup configuration user interface varies depending on the VNA modelís maximum number of ports as .s1p, .s2p, .s3p, .s4p

VNA calibration method: Short-Open-Load-Return

VNA calibration method: Short-Open-Load-Thru

SOLT or Short Open Load Thru calibration method for coaxial line types with simple and redundant standards. It is not band-limited. It requires well-defined standards. It has lower accuracy at higher frequencies. Calibrations standards with known reflection coefficients are used to calculate the correction factors. Refer to Calibration. Compare this with SSLT or Offset Short 1, Offset Short 2, Load, Thru calibration method for waveguide line types.

A spectrum analyzer measures the magnitude of an input signal versus frequency within the full frequency range of the instrument. The primary use is to measure the power of the spectrum of known and unknown signals.

VNA calibration method: Offset Short or Short-Short-Load-Thru

VNA calibration method: Triple Offset Short or Short-Short-Short-Thru. Short-Short-Short-Thru (SSLT) uses Shorts that all have different offset lengths. It is a calibration (common in waveguide or high-frequency coax) with simple and redundant standards, but it is band-limited. It requires well-defined standards. It has better accuracy at higher frequencies than SOLT, but has high sensitivity to connector repeatability errors, and is poor with on-wafer.

Time Domain Reflection - Converted S-Parameter data into an impedance profile (TDR) with an open end.

Time Domain Transmission - Converted S-Parameter data into an impedance profile (TDT) with matched terminations.

A special device, known as a terminator, connected at the beginning and end of a wire or cable to prevent an RF signal from being reflected back from each end, causing interference, or power loss. The terminator is usually placed at the end of a transmission line or daisy chain bus (such as in SCSI), and is designed to match the AC impedance of the cable and hence minimize signal reflections, and power losses.

The true RMS voltage is measured using the following method: P(avg) is the average power dissipated in a resistor R when a RMS voltage V(rms) is applied. The power is measured by a thermistor and the scale of the meter is calibrated as a ratio of temperature to resistance. This is true for any waveform and frequencies. Note that most meters you use are not true RMS meters. They measure only an average or a DC equivalent of a 60Hz pure sine wave.

Universal Fixture Extraction (UFX) provides more calibration choices for probe and in-fixture calibrations where a full set of calibration standards may not be available. It provides advanced de-embedding tools that improve the success of de-embedding test fixtures by including incremental calibration standard information as it becomes available. As a result, de-embedding of the test fixture improves, thereby improving DUT measurement accuracy.

Vector Network Analyzer (VNA)