What receiver architectures are used in RF design?

From RF Design Wiki · By the RF Design Wiki editorial team · Published October 21, 2026 · Last reviewed October 21, 2026 · How we research

The four main receiver architectures are the superheterodyne (one or more fixed IFs), direct conversion or zero-IF (RF to baseband in one step with quadrature mixers), low-IF (a small IF with complex image rejection), and direct RF sampling (an ADC digitizes RF directly). The choice balances selectivity, integration, power and impairments.^[1]

How do they compare?

Architecture	Advantages	Challenges
Superheterodyne	Excellent selectivity and dynamic range	Image and IF filters, more parts, spurs
Zero-IF	No image filter, highly integrable	DC offsets, flicker noise, IIP2, I/Q mismatch
Low-IF	Avoids DC issues, integrable	Image rejection limited by I/Q matching
Direct RF sampling	Flexible, multi-band digital processing	ADC power, clock jitter, SFDR

How is a receiver line-up analyzed?

A cascade analysis lists gain, NF, IIP3 and P1dB per stage and computes totals with Friis and the IIP3 cascade formula, then checks sensitivity, blocking, intermodulation and adjacent-channel requirements from the standard. See sensitivity and blocking.^[1]

Which architecture do modern radios use?

Highly integrated cellular, Wi-Fi and Bluetooth transceivers mostly use zero-IF or low-IF. Instruments, broadcast and high-performance radios often keep superheterodyne stages. Wideband RF-sampling ADCs and DACs are increasingly used in base stations, radar and SDRs.

Frequently asked questions

What is a dual-conversion receiver?

A superheterodyne with two IFs: a high first IF for image rejection and a low second IF for selectivity.

Why did zero-IF become common?

Integration removed the need for external IF filters and enabled multi-standard radios.

Is SDR an architecture?

SDR describes digital, reconfigurable processing; it can use any front-end architecture.

References

Online sources accessed October 21, 2026; printed works cited by edition. See all sources.

“RF Microelectronics, 2nd ed.”. B. Razavi, Prentice Hall. 2012.

Categories: Receivers and systems

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