versus CW operation
here to go to another page on pulsed RF
New for September 2008!
And of course under construction... Pulsed and CW (continuous wave)
refer to transmitter operation. Typically a transmitter is pulsed
on and off, at a specific duty cycle, this is especially true of
Before we even get to this topic,
let's discuss the word "versus". How many times must we
see the word abbreviated "vs." before we lose our minds?
This is a small word, it doesn't need to be shortened. Cut it out!
And remember that "verses" is not the same as "versus".
Learn how to use the English language good, like us does.
Back onto the topic.
In a radar, the transmitter is
turned on for a short time, then shut off while the receiver looks
for the return signal. The power amplifiers in the transmit chain
are almost always turned on and off going from transmit to receive,
this saves energy, reduces waste heat and minimizes temperature
rise in solid-state and tube devices.
a Microwaves101 Rule of Thumb!
When a solid state amplifier
is pulsed on for 100 microseconds or longer (so-called "long"
pulse), it reaches a quasi-steady-state junction or channel temperature,
so for thermal and reliability analysis, this case can be considered
the same as continuous wave. Under the same operating conditions,
to get any reliability benefits from pulsed operation you need to
operate with pulses of 10 us or less ("short" pulse)