PCBMASTER presents to you - Analysis of the Core Technologies and Application Guide of High-Frequency PCB Doppler Radar

Author: Jack Wang

When a radar emits pulsed waves of a fixed frequency to scan the air, if it encounters a moving target, there will be a frequency difference between the frequency of the echo and that of the transmitted wave, which is called the Doppler frequency. Based on the magnitude of the Doppler frequency, the radial relative motion speed of the target with respect to the radar can be measured. The distance to the target can be measured based on the time difference between the transmitted and received pulses. Meanwhile, by using the frequency filtering method to detect the Doppler spectrum of the target and filter out the interference clutter spectrum, the radar can distinguish the target signal from the strong clutter. Therefore, Doppler radars have a stronger anti-clutter interference ability than ordinary radars and can detect moving targets hidden in the background.

I. Core Technical Principles

1.Precise Measurement of Doppler Shift

①Operating frequency band: 24GHz/77GHz (standard frequency bands for automotive radars)

②Speed detection accuracy: ±0.2m/s (better than the ambiguous description in the original text)

③Range resolution: 4cm (based on FMCW frequency-modulated continuous-wave technology)

2.Upgraded Anti-interference System

①Digital Beamforming (DBF) technology: Achieves an azimuth angle accuracy of ±1°

②Adaptive filtering algorithm: Clutter suppression ratio ≥ 60dB

Multi-target tracking ability: Can handle 128 moving targets simultaneously

II. Key PCB Design Indicators

III. Key Points of Manufacturing Process Upgrades

1.Hybrid Dielectric Lamination Technology

①High-frequency layer: Rogers RO4350B (ε=3.48)

②Power layer: FR-4 TG170

③Interlayer alignment accuracy: ±25μm

2.3D Interconnection Process

①Laser blind vias: Hole diameter 80 - 150μm

②Via filling and electroplating: Depression ≤ 5μm

③Surface treatment: ENEPIG (Ni 3μm/Au 0.05μm)

IV. Improvement of the Testing and Verification System

1.Signal Integrity Testing

①Eye pattern test: Meets the IEEE 802.11ad standard

②Time Domain Reflectometry (TDR): Impedance control ±5%

③Phase consistency: ±2°@77GHz

2.Environmental Reliability Verification

①Temperature cycling: -55℃~125℃ for 1000 cycles

②Damp heat aging: 85℃/85%RH for 1000 hours

③Vibration test: 20G@50 - 2000Hz

V. Update of Industry Application Data

1.Automotive ADAS Systems

①Detection range: 250m (front radar)

②Angular coverage: ±75° (corner radar)

③Response speed: Target recognition within 100ms

2.Intelligent Security Systems

①Human body detection accuracy: 98.7%

②Micromotion feature recognition: Respiratory rate monitoring

③Penetration ability: Can detect moving targets 5m behind a wall

PCB Doppler radars are widely used in military, aviation, aerospace, transportation, meteorology, and security fields. In the military field, radar PCBs are used for target detection, navigation, and communication, providing important tactical support. In the aviation and aerospace fields, radar PCBs are used for aircraft navigation, obstacle avoidance, and target tracking to ensure flight safety. In the transportation and meteorology fields, radar PCB boards are used for vehicle and weather monitoring and early warning, providing important transportation and weather information. In the security field, radar PCB boards are used for intrusion detection, border monitoring, and target tracking to ensure security and prevention. As an important part of the radar system, PCB Doppler radars have multiple functions such as design principles, signal processing functions, performance requirements, and application fields.

If you would like to learn more about this knowledge, please feel free to contact us at www.pcbmaster.com. PCBMASTER is willing to share more topics related to this field with you at any time.

 Author: Jack Wang