This High Power 2M 144 - 148 MHz Low Pass Filter with Adaptive section (duplexer) for RF LDMOSFET is an 1000W Filter,
developed for use with the latest generation High Power LD Mosfet transistors. This high power duplexfilter is build on a silver plated Rogers Teflon PCB with silver plated copper wire inductors and Teflon PCB based capacitors. LPF is placed on an 10mm CNC machined aluminium base and covered with a aluminium cover for EMC shielding.
These extreme high power semiconductors have very high gain and often amplify up to 600MHz.
Because of this high gain and amplification up to 600MHz, a Low Pass Filter can cause serious problems. In a Low Pass Filter,
all reflected harmonics and power will be transferred back to the transistor and because the Transistor also amplifies up to 600MHz, it will “see” a very bad return loss on the harmonics it also produces.
This all can give a reduced output, reduced efficiency and a lot of extra heat to dissipate.
The design of this filter contains 2 separate sections, one Low Pass Filter section to attenuate the unwanted harmonics and a High Pass Filter with build in 50Ohm Load.
This High Pass Filter section is the key in this Filter. It has 2 functions:
1) Let the Mosfet transistor “see” a good return loss on 2nd and 3rd harmonic.
2) “Catching” most of the reflected harmonics and power from the LPF section.
With these 2 sections option we try to get the most out of your LD Mosfet Transistor.
For best performance and power handling, this LPF is constructed on a silver plated Rogers Teflon PCB with silver plated copper wire inductors and Teflon PCB based capacitors. For optimum cooling, the LPF is placed on an 10mm CNC machined aluminium base and covered with a aluminium cover for EMC shielding.
Custom changes on this product or other version can be requested by email.
