Yet another coupler
Posted: Tue Jan 16, 2018 1:40 pm
Originally thought for a more conventional use, a bidirectional monoband coupler designed for a commercial solid state PA.
Main characteristics are:
Max input power 63dBm (2.000W)
IN/OUT impedence 50 Ohm
Coupling factor -45dBm @ 28MHz
Certainly a totally different approach from conventional ones, as being monoband, the coupling factor will change radically from 10m down to 160m, by a factor of 20dB, which is what normally we try to avoid, on the other hand, it only takes a piece of FR3 PCB of 3.2mm thickness, few connectors and a box.
Well, taking the advantages of the automatic PS attenuator, I discovered that 20db are just right for my setup, as a span of 200W to 2kW will fit perfectly.
The microstrip width turned out to be 5,8mm, for a coupling factor of -45dB, the length 48,6mm.
Attached, per band attenuation table and in and out view of the coupler
73, Clay
Main characteristics are:
Max input power 63dBm (2.000W)
IN/OUT impedence 50 Ohm
Coupling factor -45dBm @ 28MHz
Certainly a totally different approach from conventional ones, as being monoband, the coupling factor will change radically from 10m down to 160m, by a factor of 20dB, which is what normally we try to avoid, on the other hand, it only takes a piece of FR3 PCB of 3.2mm thickness, few connectors and a box.
Well, taking the advantages of the automatic PS attenuator, I discovered that 20db are just right for my setup, as a span of 200W to 2kW will fit perfectly.
The microstrip width turned out to be 5,8mm, for a coupling factor of -45dB, the length 48,6mm.
Attached, per band attenuation table and in and out view of the coupler
73, Clay