X-Band T/R Module (10 GHz) with Fractal Antenna
High-performance single-channel Transmit/Receive (T/R) module for X-band phased array systems (~10–10.5 GHz), featuring integrated beamforming and a compact fractal antenna.
High-performance single-channel Transmit/Receive (T/R) module for X-band phased array systems (~10–10.5 GHz), featuring integrated beamforming and a compact fractal antenna.
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Overview
This project implements a single RF front-end module (tile) designed for scalable phased array systems.
Key features:
• X-band operation (~10–10.5 GHz)
• Integrated PA + LNA + T/R switch (QPM1002)
• Beamforming support (phase + amplitude control)
• Compact fractal antenna (14×14 mm)
• Designed for array scaling (e.g., 256+ elements)
• Optimized for automated routing (Freerouting)
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Architecture
RF IN → Phase Shifter → Attenuator → TXIN → [QPM1002] → ANT → Antenna ▲ RF OUT ← Phase Shifter ← Attenuator ← RXOUT ┘
QPM1002 Internal Structure:
• TX path: PA (~35 dBm pulsed)
• RX path: LNA (~2.2 dB NF, ~25 dB gain)
• Internal T/R switch
• Built-in power detector (VDET)
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Power Architecture
Rail Voltage Purpose TX_VD +25V Power Amplifier RX_VD +10V LNA VDD_LOGIC +5V Digital logic VDD_IO +3.3V Control interface VG -2.5V GaN gate bias
Converters:
• LM5156 (SEPIC) → 25V
• LM5017 → 10V / 5V
• Charge pump → -2.5V
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RF Components
Component Function Notes
QPM1002 T/R front-end Core RF IC TGP2109 Phase shifter (6-bit) 8–12 GHz PE43705 Attenuator (6-bit) 0.5–12 GHz
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PCB
• Substrate: Rogers 4350B
• Stackup: 4 layers (RF + GND + PWR + CTRL)
• Controlled impedance (50 Ω)
• Dense via stitching for RF grounding
• Optimized for high-frequency layout
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Thermal Design
Per module dissipation:
Block Power PA ~8 W DC-DC ~5.5 W Beamforming ~1.3 W Other ~1 W
Total: ~16 W per module
For 256 modules:
• Total ≈ 4 kW
• Requires liquid cooling
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Control Interface
• SPI (phase + attenuation control)
• GPIO (TX/RX switching)
• I²C (temperature sensors)
Logic:
• SN74HC595 (shift register)
• SN74LVTH573 (latch)
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Monitoring
• 4× TMP117 temperature sensors:
• RF front-end
• Power stage
• Beamforming chain
• PCB ambient
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Power Sequencing
Power-Up:
1. Apply VG (-2.5V)
2. Disable TX/RX
3. Enable RX_VD (10V)
4. Enable TX_VD (25V)
5. Enable TX/RX
Power-Down:
1. Disable TX/RX
2. Disable TX_VD
3. Disable RX