RF Power Meter AD8313 — logarithmic detector 0.1–2.5 GHz, module

Product detailed description

The AD8313 logarithmic detector module converts RF signal power in the 0.1 to 2.5 GHz range into a DC voltage proportional to the signal level in dBm. With a dynamic range of 70 dB (approx. −72 to −2 dBm) and a linear slope of 18 mV/dB, you can easily measure signal levels from an antenna, a transmitter via an attenuator, or a generator output using only a voltmeter or an Arduino or ESP32 A/D converter. The input is via an SMA (female) connector with 50 Ω impedance; the module features its own voltage regulator and is powered by 7–15 V. It is suitable as a simple RF power meter, signal presence detector, field strength indicator, or as feedback for automatic gain control (AGC).

Specifications:

• Chip: Analog Devices AD8313, logarithmic amplifier/detector
• Frequency range: 0.1–2.5 GHz
• Measuring range: approx. −72 to −2 dBm (dynamic range 70 dB)
• Output:
  • analogue voltage approx. 0.5–1.65 V
  • slope typ. 18 mV/dB (higher power = higher voltage)
• Input impedance: 50 Ω
• Power supply: 7–15 V DC (on-board regulator)
• Connection:
  • RFin: SMA female
  • VCC, GND: solder pads for power supply
  • OUT: measured voltage output (holes for pin headers)
• Dimensions: approx. 34 × 25 mm (excluding SMA connector)
• Mounting: 4 mounting holes at the corners of the board
• Compatibility: the output can be read by the A/D converter of Arduino, ESP32, Raspberry Pi Pico, etc.
• For measuring stronger signals, the following is suitable:
  • Digital step attenuator PE4302, 0–31.5 dB

Important wiring notice:

• The detector is designed for weak signals – the upper limit of the measurement range is approximately −2 dBm. Always connect a transmitter output or a strong signal via an attenuator; otherwise, there is a risk of damaging the chip.
• The output voltage is logarithmic – you can obtain the conversion to dBm using the relationship P [dBm] ≈ (U_OUT − U₀) / 0.018 V, where U₀ is determined by calibrating with a known signal. Both slope and offset vary slightly with frequency; for accurate measurements, calibrate at the operating frequency.
• Observe the supply voltage of 7–15 V and the VCC/GND polarity.

Package contents:

• 1× AD8313 RF power meter module with SMA connector

Note:

• This product is not a standalone functional unit and may require professional installation.
• Product images are for illustrative purposes only and may sometimes differ from the actual appearance of the item. However, this does not change their basic properties.