Radar Systems Radar Components and Subsystems Informational

How do I design the duplexer for a radar that shares a single antenna for transmit and receive?

The radar duplexer allows a single antenna to be shared between the transmitter (high power) and receiver (high sensitivity). Duplexer types: TR switch (transmit/receive switch): a fast switch (PIN diode or GaAs FET) that disconnects the receiver during transmission. Provides 40-60 dB isolation. Switching speed: 10-100 ns for PIN, < 10 ns for GaAs. Circulator-based: a ferrite circulator routes TX power to the antenna and antenna returns to the receiver, with a limiter protecting the receiver from TX leakage. Provides 20-30 dB isolation continuously, with the limiter handling the remaining power. Quasi-circulator: a hybrid coupler arrangement that provides circulator-like function without ferrite (useful at mmWave where ferrite circulators are lossy). For pulsed radar: a TR switch with a circulator provides the best combination of isolation (50+ dB during TX) and fast recovery (< 100 ns).
Category: Radar Systems
Updated: April 2026
Product Tie-In: T/R Modules, Circulators, Limiters, Waveform Generators

Radar Duplexer

Design considerations: power handling (the duplexer must survive the full TX peak power without damage or arcing), insertion loss (adds to the system noise figure on receive and reduces the effective TX power), switching speed (determines the minimum range), and bandwidth (the duplexer bandwidth must accommodate the radar's instantaneous bandwidth, including any frequency agility range).

ParameterPulsedCW/FMCWPhased Array
Range Resolutionc/(2B)c/(2B)c/(2B)
Velocity ResolutionPRF dependentDirect from DopplerCoherent processing
Peak PowerHigh (kW-MW)Low (mW-W)Moderate per element
ComplexityModerateLowHigh
Typical ApplicationSurveillance, weatherAltimeter, automotiveTracking, multifunction

Waveform Design

When evaluating design the duplexer for a radar that shares a single antenna for transmit and receive?, engineers must account for the specific requirements of their target application. The optimal choice depends on the frequency range, power level, environmental conditions, and cost constraints of the overall system design.

  • Performance verification: confirm specifications against the application requirements before finalizing the design
  • Environmental factors: temperature range, humidity, and vibration affect long-term reliability and parameter drift
  • Cost vs. performance: evaluate whether the application demands premium components or standard commercial grades
  • Interface compatibility: verify impedance, connector type, and mechanical form factor match the system architecture
  • Margin allocation: include sufficient design margin to account for manufacturing tolerances and aging effects

Detection Performance

When evaluating design the duplexer for a radar that shares a single antenna for transmit and receive?, engineers must account for the specific requirements of their target application. The optimal choice depends on the frequency range, power level, environmental conditions, and cost constraints of the overall system design.

Common Questions

Frequently Asked Questions

How does insertion loss affect performance?

TX path insertion loss: reduces the effective radiated power (directly reduces detection range). RX path insertion loss: adds to the system noise figure (also reduces detection range). A 0.5 dB duplexer loss in both TX and RX: equivalent to 1 dB total loss, reducing the detection range by approximately 6%.

What about digital TR modules?

In AESA radars: each T/R module contains its own duplexer (typically a circulator or switch). The module-level duplexer handles only the per-element power (1-50W), much lower than the total array power. This makes the duplexer design much simpler and cheaper than a single high-power duplexer for the entire array.

Need expert RF components?

Request a Quote

RF Essentials supplies precision components for noise-critical, high-linearity, and impedance-matched systems.

Get in Touch