High gain 35W VHF wideband amplifier
This 35W pallet amplifier covers wide frequency range with no adjustment and offers very high gain necessary for DAB+ and other applications. It can produce full output power from just a few milliwatts of drive power over very wide frequency range.
Each pallet amplifier we sell is designed and tested using vector network analyzer and spectrum analyzer. Our amplifier products are manufactured using an automatic surface mount assembly process. This pallet is optimized for 48-65V operation and is a perfect driver for new LDMOS devices which work with these high voltages. Using a lower voltage will result in lower output power. It will operate down to about 24 volts with reduced output. RF output power can be adjusted by lowering the supply voltage or reducing the drive. Bias can be adjusted with a trimmer and is thermally stabilized. For high-linearity applications please increase bias current as needed. The pre-driver high gain circuit is operating in linear mode always.
As with any pallet you will need a heat-sink, power supply and filter to use it. More information is available in the included amplifier’s data sheet.
Due to high gain the 35W pallets can be powered practically from the DAB+ DDS, an isolation stage and shielding are recommended for stability. Practically any source you can imagine will be strong enough to drive this pallet amplifier.
When using high-gain version with on-board pre-amplifier you also need an additional 8V DC mains power supply for the pre-driver stage.
– Frequency range: 80-250MHz
– Input/output impedance: 50 ohms
– Pout max: >35W @100MHz (65V, CW)
– Pout max: ~10W @200MHz (65V, DAB+)
– Pout max: >50W@65V
– Drive power required: ~10mW (monitor output to avoid overdriving)
– Main power supply: 48-65Vdc: ~1.5A max at 35W CW (DO NOT EXCEED 65V)
– Pre-driver power supply: 8V DC, 200mA
– Gain without pre-amplifier stage: 25-28dB
– Gain with pre-amplifier stage: ~35-40dB
– No bias adjustments or RF circuit tuning is required.
– Size: 46x49mm, 20mm high
Suitable mains power supply are here.
Warning: Do not exceed maximum supply voltage of 15V or damage will occur to the on-board operational amplifier.
Note 1: Please use PTFE coaxial cable for RF input (RG178 is perfect) and output (RG178 or RG142 are perfect) connections, this makes it possible to have very short leads without burning the coax. Keep the coax leads as short as possible (few mm at most). Also keep leads short on connectors, this N female flange for RG142 or .141 semirigid – easy install is perfect!
Note 2: A small heatsink is definitely needed!
Note 3: There are signs of soldering on each board. This is due to testing (during testing coaxial cable is attached).