2
ISOMET
1.
GENERAL
Key Features:
•
24Vdc, water cooled high power amplifier
•
RF output >150W at 40.00MHz, and >150W at 50.67MHz
•
RF rise/fall time < 400/100nsec at 150W
•
High Speed Digital ON:OFF modulation
•
Modulation ON level is defined by two methods for each frequency
- Digitally programmed potentiometer stack
- Manual adjustment potentiometer.
•
Digital potentiometers programmed via buffered I2C interface
•
Opto-isolated PLC compatible inputs on POT select and RF enable inputs.
(Response time < 1msec)
•
Tri colour LED status indicator
•
High VSWR shut-down protection
The RFA741 Combined Driver and Power Amplifier is a fixed dual frequency RF power source
specifically designed to operate with the AOM740- series of acousto-optic high power modulators
A block diagram of the driver is shown in Figure 3. The center frequencies are determined by free-
running quartz-crystal oscillator. The frequency is accurate to within
±
25ppm and the stability is
better than
±
25ppm. A high-frequency, diode ring modulator provides high speed amplitude
modulation of the RF carrier. The peak RF power level for each frequency is set by a multi-turn
manual potentiometer or by digitally controlled potentiometers.
The prime frequency of 40MHz provides the active “ON” laser output beam. The dummy frequency of
50.67MHz is applied in the “OFF” condition and is used to provide a constant thermal load to the
AOM.
