Elecbee AD8317 RF Logarithmic Power Detector Module 1MHz-10GHz

Elecbee AD8317 RF Logarithmic Power Detector Module

The Elecbee AD8317 RF logarithmic power detector module converts an RF input signal into a corresponding linear-in-decibels DC voltage. It supports frequencies from 1MHz to 10GHz and is designed for RF signal detection, transmitter level monitoring, RSSI measurement, laboratory development and feedback-control applications.

Technical Specifications

• Detector IC: Analog Devices AD8317
• Operating Frequency: 1MHz–10GHz
• Accurate Logarithmic Response: 1MHz–8GHz
• Extended Useful Operation: Up to 10GHz
• Nominal Board Input Range: Approximately -55dBm to 0dBm
• Dynamic Range: Typical 55dB through 8GHz with less than ±3dB error under specified conditions
• Typical Logarithmic Slope: -22mV/dB
• Nominal Board Output: Approximately 0.33–1.65V DC
• Output Characteristic: Voltage decreases as RF input power increases
• Nominal Input Impedance: 50 ohms
• Board Supply Input: 7–15V DC according to the supplied board specification
• AD8317 IC Supply Requirement: 3.0–5.5V provided through the board’s regulator circuit

Negative-Slope Logarithmic Output

The module provides an analog DC output that changes linearly with the logarithm of the RF input amplitude. Because the AD8317 has a negative transfer slope, a weaker RF signal produces a higher output voltage and a stronger RF signal produces a lower output voltage. This relationship must be considered when processing the output with an ADC, microcontroller or control circuit.

RF Power Measurement

The board’s nominal input range is approximately -55dBm to 0dBm, but this range should not be treated as a guaranteed limit across the complete 1MHz–10GHz bandwidth. Detector accuracy, slope and intercept can change with frequency, temperature, waveform, impedance matching and individual module variation.

For absolute power measurements, calibrate the assembled system using known RF input levels. The resulting slope and intercept values can then be used to convert the measured DC output voltage into an estimated RF input level in dBm.

Applications

• RF signal presence and level detection
• Transmitter and power-amplifier output monitoring
• RSSI and wireless signal-strength measurement
• RF laboratory and engineering projects
• Calibrated environmental field-strength monitoring
• Automatic gain control and automatic level control feedback

Integration Information

The module is intended for use in a nominal 50-ohm RF signal path. According to the supplied board information, the board accepts a 7–15V DC input and must use an onboard regulator to provide the AD8317 with its required 3.0–5.5V supply. Confirm the regulator, input polarity and terminal assignments before applying power.

This product is an analog RF detector module rather than a standalone calibrated power meter. It does not include a display or direct digital dBm readout. External measurement hardware and application-specific calibration are required for accurate quantitative measurements.

Note: The AD8317 is a demodulating logarithmic detector rather than a true-RMS power sensor. Readings can vary between continuous-wave and modulated signals with different waveform characteristics or crest factors.