Idea replies — I know radio communication well and I’m building an advanced receiver. Who could help me design the circuit?

Nice project. Before picking an IC, pin down three numbers: frequency range, channel bandwidth, and the weakest signal you want to hear (sensitivity). Then: for flexibility, an SDR front end is the easiest path (RTL-SDR/R820T for a cheap start, AD9361/AD9363 or LMS7002M for serious wideband work). For a single band, a dedicated chip like the Si4735 (AM/FM/SW) or an SX127x/CC1101 (sub-GHz digital) is simpler. Whatever you choose, sensitivity is mostly decided before the chip: a good LNA placed right after the antenna, a band-pass filter in front of it, and a clean, well-shielded supply. Happy to look at your requirements and sketch the block diagram if you want.