RTL SDR

Built around the Analog Devices AD9363 (often soft‑unlocked toward AD9364 behavior). This chip is a fully integrated wideband zero‑IF transceiver: on the RX side it's LNA → quadrature mixer driven by a tunable on‑chip RF synthesizer (the LO) → analog I/Q baseband → programmable baseband filters → ADCs → on‑chip decimation; on TX it runs the same chain in reverse (DACs → quadrature modulator → RF). So it mixes to/from baseband in the analog domain across its whole range (~325 MHz–3.8 GHz stock, ~70 MHz–6 GHz hacked).

The Pluto is the "grown‑up" version of your RTL-SDR front end: same zero‑IF idea, but wideband, bidirectional, with much better converters and integrated DSP.

ALDM-PLUTO

Need to work up a block diagram of this little polynomial like I did for the SDR Radio (RTL-SDR).