This filter is intended for 2m amateur radio band.
This filter is two pi cell, inductively coupled (L4).
My requirement for this filter are 50dBm power handling, less than 1dB of loss in 2m band and at least 40dB isolation at 291,6Mhz.
To avoid a loss of isolation at high frequency, coupling must be avoided between cells. Thefore, a conductive enclosure is mandatory.
Loss at the frequency of interest is only 0.6dB.