RF Theory

Gain types, noise figure, P1dB, IIP3, stability — LNA vs PA vs VGA explained.

PA classes A/AB/B/C/D/E/F, Doherty, PAE, load pull. GaN vs GaAs vs LDMOS.

Upconversion, downconversion, IQ mixers, conversion loss, isolation, image rejection.

Interactive spur table — image, half-IF, IM2, IM3, LO harmonics. Live spectrum view.

Butterworth, Chebyshev, Bessel — prototype tables, denormalisation, SAW vs BAW vs LC.

Barkhausen criterion, Colpitts/Clapp/Hartley, phase noise, Leeson's equation, crystal vs MEMS.

Charge pump, loop filter, phase noise, lock time, integer-N vs fractional-N, ΣΔ modulator.

What each device does, ferrite circulators, TX/RX isolation in FDD, diplexer splitting.

Superhet vs direct conversion vs zero-IF, full RX/TX chain, FDD vs TDD, dynamic range.

AM, FM, BPSK, QPSK, 16/64/256-QAM, OFDM — IQ phasor, constellation diagrams, EVM, PAPR.

Thermal noise, noise figure, Friis cascade, receiver sensitivity, SFDR, dynamic range.

EIRP, path loss, sensitivity, fade margin — worked examples for WiFi, LTE, satellite, radar.

Range equation, RCS, pulse vs FMCW vs CW, range resolution, Doppler, pulse compression.

Amplitude & phase comparison monopulse, sum/difference beams, angle error voltage, squint angle, null depth, boresight accuracy and the tracking loop.

Nyquist, aliasing, undersampling, SFDR, ENOB, aperture jitter, ADC architectures, DAC sinc rolloff.

Gain, directivity, EIRP, HPBW, polarisation, near/far field, radiation patterns, feed impedance.

ULA/URA, array factor, beam steering, amplitude tapering, grating lobes, 5G massive MIMO.

Telegrapher's equations, impedance, VSWR, standing waves, stubs, λ/4 transformer.

L-network, pi, T-network, λ/4 transformer, single & double stub. Smith chart walkthroughs.

What each S-parameter means, how a VNA works, calibration, Smith chart geography, Touchstone.

Stackup, return currents, via stubs, crosstalk (NEXT/FEXT), EMI, differential pair routing.

130+ RF & microwave terms defined in plain English — NF, VSWR, IIP3, EIRP, EVM, SFDR, phase noise and more. Searchable & filterable by category.