Re: UHF bandpass filter

My question is: are you sure the image frequency stands only on 295 MHz? If the RF bandwidth is 42 MHz, and this is a multichannel superhet receiver, the frequency swing of the first LO is also 42 MHz, making the resulting image frequency to swing in the same way.
In this case a notch for 295 MHz is good only for one image frequency.

Such filter specifications can be reached with interdigital filter.

Yes, a basic top (C) coupled LC resonator design could work here. eg a 4th order filter. This could be made to be very small although I would be wary of unwanted coupling between resonators. If this proves to not be a problem then this filter would be the smallest and probably the fastest to prototype. The top C coupled design gives a very steep rolloff on the lower stop bandmaking it very attractive for this design. It might be possible to use Coilcraft mini spring SMD inductors and this could make the design more repeatable.

The combline filter would be bigger but much cheaper (eg ￡2 in parts) assuming the design was incorporated into the main PCB as it only requires 6 or 7 capacitors all of the same value. eg 10pF.

The stacked mini circuits filters would also be a good choice although they are quite expensive if you include delivery charges as well. A lot depends on the budget for the design.

An interdigital filter would be very big unless a high dielectric material was used for the PCB.