Keysight Technologies N5171B EXG, Руководство пользователя

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Keysight EXG and MXG X-Series Signal Generators User’s Guide 443
Nyquist filter Also referred to as a cosine filter. These filters have the property that their impulse
response rings at the symbol rate. Adjacent symbols do not interfere with each other at the symbol
times because the response equals zero at all symbol times except the center (desired) one.
P
Persistent That which is unaffected by preset, user preset, or power cycle.
Point-to-point Time In a step sweep ( page 47 ), the sum of the dwell time, processing time,
switching time, and settling time.
R
Rectangular filter Also referred to as a ideal low pass filter. These filters have very steep cut-off
characteristics. The pass band is set to equal the symbol rate of the signal. Due to a finite number
of coefficients, the filter has a predefined length and is not truly “ideal”. The resulting ripple in the
cut-off band is effectively minimized with a Hamming window. This filter is recommended for
achieving optimal ACP. A symbol length of 32 or greater is recommended for this filter.
Root Nyquist filter Also referred to as a Root cosine filter. These filters have the property that their
impulse response rings at the symbol rate. Adjacent symbols do not interfere with each other at the
symbol times because the response equals zero at all symbol times except the center (desired) one.
Root Nyquist filters heavily filter the signal without blurring the symbols together at the symbol
times. This is important for transmitting information without errors caused by ISI. Note that ISI does
exist at all times except the symbol (decision) times. A cascade of two of these filters has the
transfer function of a Nyquist filter. One is in the transmitter, the other in the receiver, so that the
system taken as a whole has the zero-ISI properties of an ISI filter.
RMS Root mean square. A time-varying signal’s effective value (the equivalent DC voltage required
to generate the equivalent heat across a given resistor). For a sinewave, RMS = 0.707 x peak value.
S
Softkey A button located along the instrument’s display that performs whatever function is shown
next to it on that display.
T
TCP Transmission control protocol. The most common transport layer protocol used on Ethernet
and the Internet.
Terminator A unit indicator (such as Hz or dBm) that completes an entry. For example, for the entry
100 Hz, Hz is the terminator.
Type-N Connector Threaded RF connector used to join coaxial cables.
U
USB Universal serial bus. See also http://www.usb.org