Here the 400W RF power amplifier circuit build using power MOSFET FQA11N90. This Class E RF amplifier will provide approximately 400 watts of RF output, depending on the input voltage and tuning parameters (current). The amplifier utilizes low-cost IXDD414 Driver ICs - one for each two MOSFETs. Transient Voltage Supressors (TVS devices) are applied on the gates, drain bus and modulated DC input towards the RF amplifier to secure the MOSFETs from damage because of accidental overvoltage. The carrier DC voltage ought to be between 40 volts and 50 volts, and not greater than 135 volts at full positive peak modulation.
The 8 MOSFET RF amplifier contains two identical four MOSFET RF amplifier stages connected together in a single ended push pull configuration. Every single amplifier stage (module) involves an RF driver (IXDD414 ICs), one IC for each two MOSFETs. The driver IC inputs are connected together to form a semi "bus", with a 100 ohm termination resistor connected to ground at each end of the driver bus, forming a 50 ohm termination. The drivers are connected towards the VFO working with 50 ohm coaxial cable.
Every driver bus is driven out of phase with the other, so when one is "on" the other is "off". The outputs are also mixed out of phase, giving the single ended, push pull configuration. TVS (TransZorb) devices are utilized on the drain and gate busses, and on the modulated DC input to every amplifier stage.
For complete explanation about this 400W RF power amplifier circuit, please visit www.classeradio.com
No comments:
Post a Comment