Wilkinson divider for 145 MHz

For operation on 2320MHz I needed a receive power splitter for my IF 144 MHz. It had to cover the 100-150 MHz range.

The first idea was to build a resistive power divider but I ended up with a Wilkinson divider. Because of the long pieces of coax I decided

to build the Wilkinson divider out of lumped parts. In order to keep small.

It had to be a quick and dirty project, so I used a tinned box.

The circuit diagram:

 

wilkinson-lumped-150mhz

 

The simulation showed the following result:

 

wilkinson-lumped-150mhz-sweep

 

It was decided to keep things simple. I used 4 capacitors, each 22 pF and 2 small air coils. I had to fiddle a bit because the box was a bit to big.

I ended up with 6 turns on a 4mm diameter about 12mm long. As you can see on the photo I had to stretch the coils a bit, I tried to make it a bit more wideband.

 

wilkinson-150mhz-klein

 

Measurements:

Centre frequency 150 MHz and a span of 100 MHz.

 

s21-wilkinson-klein

 

The isolation between the ports is shown below:

 

s23-wilkinson-klein