How to design and make a high performance,ultra small, rf bandpass filter at 915MHz

HI everyone, my name is Ian and I am an RF and Antenna Design Engineer.For the last 6 months, I have been developing several low cost,high performance rf products which are not really out there in the market place to buy. I have been selling these products on Tindie.I have just started designing another new product and I thought it might be interesting to generate a blog on Hackaday.io telling everyone all the in's and out's of the design process starting this new product design until I finally have a finished product in my hand. So lets make a start but remember,this is my first ever blog so I am learning all the time so do not expect it to be as polished as some other blogs but hopefully you will find the content interesting. I will try and update this blog regularly as the new product design progresses.

The new product design will be a 915MHz bandpass filter with a passband from 902MHz to 928MHz and the target size of the pcb will be 10mm by 12mm and the maximum rf input power will be +23dbm. Also,this pcb will contain both an input and and output high performance rf connectors. The bandpass filter will be designed to give excellent rejection across the band 1MHz up to 6GHz. The main target of this design is to produce a fully working,high performance rf bandpass filter that is far smaller than anything else out there in the marketplace and which can be easily retrofitted into many types of radio transceivers which may be suffering from blocking effects of nearby 4G,5G,etc rf transmitters. So thats Part1 which has set the scene for what I am trying to achieve with this new product design. Part 2 will start getting a little bit more technical but I hope you will keep with me.