Boonton 4540 Peak Power Meter User Manual - Manual (Page 234)

Boonton 4540 Series RF Power Meter
Application Notes 6-6
Table 6-1. Pulse Terms
TERM DEFINITION
Base Line
The two portions of a pulse waveform which represent the first nominal state from which a pulse departs
and to which it ultimately returns.
Top Line
The portion of a pulse waveform which represents the second nominal state of a pulse.
First Transition The major transition of a pulse waveform between the base line and the top line (commonly called the
rising edge).
Last Transition The major transition of a pulse waveform between the top of the pulse and the base line. (Commonly called
the falling edge.)
Proximal Line
A magnitude reference line located near the base of a pulse at a specified percentage (normally 10%) of
pulse magnitude.
Distal Line
A magnitude reference line located near the top of a pulse at a specified percentage (normally 90%) of
pulse magnitude.
Mesial Line
A magnitude reference line located in the middle of a pulse at a specified percentage (normally 50%) of
pulse magnitude.
6.3 Automatic Measurements
The 4540 Series power meters automatically analyze the waveform data in the buffers and calculate key waveform
parameters. The calculated values are displayed in text mode when you press the GRAPH/TEXT system key.
6.3.1 Automatic Measurement Criteria
Automatic measurements are made on repetitive signals that meet the following conditions:
Amplitude. The difference between the top and bottom signal amplitudes must exceed 6 dB to calculate
waveform timing parameters (pulse width, period, duty cycle). The top-to-bottom amplitude difference
must exceed 13 dB to measure rise and falltime.
Timing. In order to measure pulse repetition frequency and duty cycle, there must be at least three signal
transitions. The interval between the first and third transition must be at least
1/5 of a division ( 1/50 of the
screen width). For best accuracy on rise and falltime measurements, the timebase should be set so the
transition interval is at least one- half division on the display.