High Power Amplifier
Triode Based RF Pulse Amplifier
64 KW, 1250 – 1350 MHz.

 
 

SPECIFICATIONS

FREQUENCY1250 TO 1350 MHz
POWER OUTPUT64 KW PEAK
DYNAMIC RANGE40 dB
RF GAIN20 DB
GAIN VARIATION+/- 1 dB BELOW 10 dB DOWN
+1/-3 ABOVE 0 dB DOWN
SPURIOUS-50 dBc IN BAND
HARMONICS-30 dBc
IMPEDANCE INPUT & OUTPUT50 OHMS
INPUT VSWRLESS THAN 1.5:1
PULSE WIDTH1 TO 4 µSEC
DUTY CYCLE.0035
MODULATOR INPUT PULSE5 VOLTS
DIMENSIONS26" x 29" x 10"
 
DESCRIPTION: Two stage amplifier.
         Each stage has a gain of 10 dB. Both stages are triode based. Circulators are installed between stages to minimize the effects of impedance mismatch. The loads are not meant to handle full reflected power. The first stage employs a single tuned input cavity and an over-coupled, double tuned output cavity to create a bandwidth of 100 MHz.
         The final stage is a unique design with four triodes in a multimode resonator. The anodes of the amplifier tubes are connected to a multimode resonator where their outputs are combined. Correct phasing of the individual tubes is achieved by controlling the lengths of the interstage coax cables. A second multimode resonator is coupled to the first to form an over coupled, double tuned band-pass transformer. Output load matching is accomplished with a capacitive divider within the resonator.

 
         The photograph above shows one of ten units built for the Mini-MUTES electronic warfare training system. It was designed to handle vibration and wide thermal swings. We use a unique output cavity design to broaden the band and a unique combiner to add up the output of multiple tubes. Each stage has 10dB of gain. More stages can be added to the input or the output side to increase the gain. We are currently building a 100kW amplifier with 50dB of gain. Click for more details.

 

 

Bias Modulator

The bias modulator circuit is compact and adjustable to provide maximum linearity. Bias voltage is pulsed to completely shut off RF during the interpulse period.

Driver Cavities

Driver cavities can be chained together, 10dB gain each, for a practical input power of 5W and an output of up to 5kW. The amplifiers are designed for maximum pulse widths in the 4µS range and duties in the 0.35% range. Custom parts are produced by our in-house machine shop to exacting specifications.

 

 

 

 

Final Combiner

Final combiners have 10 dB of gain each and they are also stackable for outputs from 10kW to 100kW. The stages are air cooled so there’s no need to worry about pumps, heat exchangers or a glycol mix. Pressure switches warn in case of air flow loss.

For turnkey systems we supply touch screen control that enables central monitoring of faults and power supplies. Systems can be run remotely through an Ethernet cable.

High Voltage Assembly

The high voltage assemblies are enclosed for safety. They are air filled rather than oil filled to keep them light and easy to access. They incorporate a crowbar to dump the energy in case of a tube arc.