User's Manual

IV-1
Section IV – RF Components
Amplifier Pallets
The TECH-30U driver pallet consists of (2) separate printed circuit board stages – The first stage is an
ultra-linear class-A stage with (3) gain sections providing a typical adjustable power gain of 26dB to
37dB at 10-watts peak. This stage typically draws 2.5 Adc quiescent and a maximum drain current of 5
Adc. The second stage is a linear class AB stage with a typical gain of 13 dB. This stage typically
draws 1.0 Adc quiescent and a maximum drain current of 10 Adc. The currents on both stages can be
found by measuring the voltage drop across the +30 Vdc input and the I sense connector. The
resistance separating these connections is 0.01 ohms, providing a 10 mV per ampere ratio.
The P300-UHF pallets used in the final amplification stage use LDMOS (Laterally Diffused Metal Oxide
Semiconductor) technology. LDMOS technology offers higher gain, efficiency and linearity over
standard MOSFET and Bipolar devices and enhances ruggedness and reliability. LDMOS transistors
have the added advantage of not having BEO (Beryllium Oxide) in their construction. The P300-UHF
amplifier pallets have a typical gain of 15dB (14dB minimum) and draw no more than 23Adc. Currents
for these pallets must be measured with an ammeter in series with the power supply lead.
Each of the amplifier pallets is connectorized to optimize servicing and accessibility. All amplifier pallets
must have the transistor drain voltages reach at least 26Vdc before the RF drive is applied.