A suggested path for students and engineers moving into RF. Adjust to your background.

Stage 1: Foundations
- Circuit theory, complex numbers and phasors, Fourier analysis.
- Electromagnetics: Maxwell's equations, plane waves, boundary conditions.
- Transmission lines: characteristic impedance, reflection, standing waves, input impedance of loaded lines.

Stage 2: Core microwave engineering
- S-parameters and network analysis, Smith chart, impedance matching.
- Passive components: couplers, dividers, filters, resonators.
- Noise: noise figure, noise temperature, Friis cascade.
- Nonlinearity: compression, intermodulation, dynamic range.
A standard microwave engineering textbook with worked problems is the best investment here.

Stage 3: Building blocks
- Amplifiers (LNA, PA), mixers, oscillators and PLLs, switches.
- Antennas: fundamental parameters, dipoles, patches, arrays.
- Radio architectures: superheterodyne, zero-IF, low-IF, direct sampling.

Stage 4: Practice
- Learn a circuit simulator and an EM tool. Free options exist (for example Qucs-S for circuits and openEMS for EM).
- Get hands-on with measurement: a VNA (even an inexpensive hobby model for learning), a spectrum analyzer, and an SDR. Measure filters and antennas you build.
- Design, fabricate and measure a simple board: a microstrip filter, a matched amplifier from an evaluation part, or a patch antenna. Compare measurement with simulation and explain the differences.

Stage 5: Specialize
Pick an area (front-end design, antennas, microwave photonics, test, RFIC) and read recent conference papers in it (IMS, EuMW, and similar).

Habits that help
- Keep a lab notebook with setups and calibration details.
- Always estimate the answer before simulating or measuring.
- Ask for design reviews and post your questions here.