24GHz ISM Band Radar Transceiver Module (Infineon BGT Series)

This project features a precision-engineered RF PCB designed around the Infineon BGT24 series monolithic microwave integrated circuit (MMIC). It serves as a compact 24GHz radar frontend, capable of supporting Doppler (motion/speed) and FMCW (distance/presence) radar applications. The design focuses on signal integrity and accessibility, breaking out critical RF and analog signals for analysis or processing. Technical Highlights & Architecture Core RF Engine: Chipset: Infineon BGT24 Series (likely BGT24MTR11 or BGT24LTR11 based on the visible I/Q and V_TUNE topology). Frequency Band: Operates in the 24.0 – 24.25 GHz ISM band, making it license-free for most industrial and consumer applications. Architecture: The board supports full quadrature structure (I and Q channels), allowing for the detection of both speed and direction of motion. RF & Analog Interface: SMA Connectors: Equipped with high-frequency SMA connectors for connecting external high-gain antennas or interfacing directly with spectrum analyzers/oscilloscopes for signal characterization. Control Signals: Features a dedicated header (H1 area) for easy interfacing with a microcontroller (like Arduino, STM32, or ESP32). V_TUNE: Input for Frequency Modulated Continuous Wave (FMCW) control, enabling distance measurement. TX_EN: Logic control to enable/disable the transmitter for power saving. IF Outputs (I/Q): Differential or single-ended intermediate frequency outputs for signal processing. PCB Design & Layout: RF Optimization: The red layout view reveals a meticulously designed RF ground plane with extensive via stitching (shielding vias) surrounding the high-frequency tracks. This suppresses electromagnetic interference (EMI) and prevents signal leakage. Controlled Impedance: RF traces are routed with precise geometry to match 50-ohm impedance, minimizing reflections and signal loss. Thermal Management: The design includes thermal relief patterns and ground pours to dissipate heat generated by the RF MMIC. Onboard Diagnostics: PTAT Output: Breakout for the "Proportional To Absolute Temperature" sensor, allowing the host system to monitor the radar chip's temperature and apply compensation algorithms.