EMC/EMI probe low-noise amplifier

This EMC/EMI electromagnetic radiation amplifier is used for electromagnetic radiation noise detection and amplification in electronic products. It serves as a pre-amplifier for RF power amplifiers, with a built-in power supply providing independent power for up to 3 hours of continuous operation, or it can be externally powered. The input connects to a probe, and the output signal can be directly fed into a spectrum analyzer or RF power amplifier.
Open source protocol: CC-BY-NC-SA-4.0.
Parameters:
Frequency range: 0.05GHz-4GHz;
Amplification gain: 20dB (two-stage amplification)
; Impedance: 50Ω; Power
supply: 5V-1A;
Battery capacity: 250mAh (3 hours of continuous operation on a full charge)
; Probe: 50Ω impedance;
RF section low-noise amplifier chip: SPF-5189Z;
Two-stage amplification, 10dB per stage, 20dB for both stages; Vector
grid amplification gain test: A -30dB gain attenuator is inserted in series in the RF circuit, interface loss has been calibrated, line loss is approximately 1.95dB; Vector grid amplification gain test: A low-noise gain amplifier is inserted in series, total attenuation is 10.99dB = 30dB - 20dB.
(Note: The charge pump and low-noise amplifier chip will generate heat during operation. Without proper cooling, the charge pump will overheat and trigger overheat protection, reducing the amplification gain of the low-noise amplifier.)
The power supply uses a lithium battery, with the charge pump boosting voltage to reduce power supply noise. The charge pump uses the HX4002, and the
charging management uses the small-size TP4057 charging management chip. (Note: The charge pump and low-noise amplifier chip will generate heat during operation. Without proper cooling, the charge pump will overheat and trigger overheat protection.)
The probe is a panel; after prototyping, it needs to be disassembled and the cross-section ground. Different probes are suitable for different detection areas.
The housing is a lightweight aluminum alloy. For cost reasons, a pre-made housing was chosen, but this housing has gaps during assembly. To achieve lower noise and avoid external interference, a CNC-machined housing is recommended.
Processing parameters: CAD drawings; please send the drawings to the manufacturer for processing.
Front panel:
Rear panel:
Remarks: (Laser marking is recommended for the font parts)
PCB assembly effect:
Heat sink added to the heat-generating parts:
Complete component drawing:
Assembled product drawing:
Simulation drawing:
CAD processing images and CNC processing files for the outer shell are attached.
Test video: The interference source is a 0.05~4GHz 20dB gain buzzer at the bottom of the microcontroller development board.
It is a self-powered low-noise amplifier for EMC/EMI electromagnetic leakage detection in electronic products. It comes with a self-made probe.