| Metadata | Details |
|---|
| Publication Date | 2021-04-01 |
| Journal | Journal of Instrumentation |
| Authors | C. Hoarau, G. Bosson, J.-L. Bouly, S. Curtoni, D. Dauvergne |
| Institutions | Centre National de la Recherche Scientifique, Université Grenoble Alpes |
| Citations | 10 |
| Analysis | Full AI Review Included |
- Core Value Proposition: Development of an ultra-low power, high-speed Low Noise Amplifier (LNA) optimized for reading out CVD-diamond particle detectors in hadron therapy applications.
- Power Efficiency: Achieved extremely low power consumption of 72 mW per channel, crucial for enabling high-density, multi-channel readout systems (up to 40 strips) in limited space.
- Speed and Timing: The two-stage Si-Ge HBT/LNA architecture delivers a fast rising time (T20/80) of 350 ps and excellent timing resolution, with jitter measured as low as 43 ps.
- Gain and Bandwidth: The amplifier provides a high gain of 43 dB, maintaining a wide bandwidth with 31 dB gain remaining at 2 GHz, suitable for amplifying fast, nanosecond-duration pulses from diamond detectors.
- Design Methodology: Utilizes cost-effective Surface-Mount Device (SMD) components and RF layout techniques (coplanar grounded waveguide on FR4) to ensure timing performance and controlled impedance (55 Ω).
- Detector Compatibility: The design incorporates necessary high-voltage biasing capability (~500 V) required for operating diamond detectors and handles input charges ranging from 7.5 fC (protons) to 520 fC (carbon ions).
| Parameter | Value | Unit | Context |
|---|
| Total Power Consumption | 72 | mW | Per channel (Target: < 75 mW) |
| LNA Gain (Nominal) | 43 | dB | Overall design gain |
| LNA Gain (Measured) | 46 | dB | At 10 MHz |
| LNA Gain (Measured) | 31 | dB | At 2 GHz |
| LNA Gain (Measured) | 23 | dB | At 3 GHz |
| Rising Time (T20/80) | 350 | ps | Simulated and measured |
| Propagation Delay | 750 | ps | Measured |
| Timing Jitter (Minimum) | 43 | ps | At 25% trigger level |
| Equivalent Noise Charge (ENC) | 230 | e | Estimated |
| Noise Figure (Calculated) | 0.72 | dB | Between 400 MHz and 4 GHz |
| Input Noise Voltage Density | < 1 | nV/sqrt(Hz) | Measured across 2 GHz bandwidth |
| Detector Bias Voltage | ~500 | V | High voltage line for charge collection |
| Substrate Material | FR4 | - | Printed Circuit Board (PCB) |
| Substrate Thickness | 0.8 | mm | PCB thickness |
| Characteristic Impedance | 55 | Ω | Coplanar grounded waveguide design |
| Diamond Thickness (sCVD) | 500 | ”m | Tested detector thickness |
| Electrode Thickness | 100 | nm | Aluminum electrodes |
| Input Charge Range | 7.5 to 520 | fC | Protons (70 MeV) to Carbon ions (95 MeV/nucleon) |
- LNA Architecture: Implemented a two-stage amplifier design using discrete surface-mount components (SMD 0603) to minimize package parasitic effects and control costs.
- Component Selection: The first stage utilized a wideband NPN RF Si-Ge Heterojunction Bipolar Transistor (HBT), the Infineon BFP740, configured in common emitter mode for optimal noise and timing match. The second stage used an integrated Low Noise Amplifier, the Infineon BGA427.
- Simulation and Modeling: Spice S-parameters simulations were conducted using LTSpice, incorporating standard Gummel and Poon transistor models supplied by Infineon, along with models for SMD component parasitic effects (e.g., 120 fF parallel capacitance, 140 pH serial inductance).
- PCB Layout and Impedance Control: The PCB was designed on a 0.8 mm thick FR4 substrate. A coplanar grounded waveguide structure was used (1.2 mm width, 1 mm gap) to achieve a characteristic impedance of approximately 55 Ω, balancing line width and impedance requirements.
- Biasing and Power Optimization: A compromised biasing point (3.8 V, 19 mA) was selected to achieve the target low power consumption (72 mW). The high voltage line (~500 V) for detector biasing was spaced 3 mm from ground to prevent sparking.
- Frequency Domain Characterization: Scattering parameters (s21, s11, s22) and noise voltage density were measured using a Vector Network Analyzer (R&S ZNL6) with a 50 Ω input termination.
- Time Domain Testing: Pulse response was measured using a fast pulse generator (Agilent B1110A). Application-equivalent testing was performed using a 241Am alpha source coupled to a 500 ”m sCVD diamond detector, allowing for jitter and noise extraction from oscillograms.
- Hadron Therapy Instrumentation: Direct application in beam tagging and monitoring systems for proton and carbon-ion therapy, providing high-resolution time-stamping necessary for online dose control and Bragg peak localization.
- High-Rate Particle Physics: Suitable for front-end electronics in high-luminosity experiments requiring fast timing (picosecond resolution) and low power consumption for multi-channel readout of strip detectors (e.g., diamond or silicon).
- High-Density Detector Readout: The ultra-low power (72 mW/ch) and compact SMD design enables the construction of large-scale hodoscope arrays (up to 40 channels per board) where thermal management and space constraints are critical.
- Fast Radiation Spectroscopy: Use in systems requiring the amplification of low-charge, fast-transient signals generated by solid-state detectors, such as diamond CVD sensors, for high-speed counting and energy measurement.
View Original Abstract
Abstract This article introduces a design of a Low Noise Amplifier (LNA), for the field of diamond particle detectors. This amplifier is described from simulation to measurements, which include pulses from α particles detection. In hadron therapy, with high-frequency pulsed particle beams, the diamond detector is a promising candidate for beam monitoring and time-stamping, with prerequisite of fast electronics. The LNA is designed with surface mounted components and RF layout techniques to control costs and to allow timing performance suitable for sub-nanosecond edges of pulses. Also this amplifier offers the possibility of high voltage biasing, a characteristic essential for driving diamond detectors. Finally the greatest asset of this study is certainly the minimization of the power consumption, which allows us to consider designs with multiple amplifiers, in limited space, for striped diamond detectors.
- 1980 - A SILICON SURFACE BARRIER MICROSTRIP DETECTOR DESIGNED FOR HIGH-ENERGY PHYSICS [Crossref]
- 1991 - CMOS low noise amplifier for microstrip readout: Design and results [Crossref]