AD8307 USB 0-500MHz RF Power Meter Component List:
1x PIC18F2550 Programmed Microcontroller
1x AD8307 RF Power Meter IC
1x RF Power Meter Probe PCB
1x USB IO Board PCB
1x USB Type B Connector
1x 20MHz Crystal Resonator
1x 470K Resistor (yellow purple yellow gold)
2x 10K Resistor (brown black orange gold)
2x 100 Resistor (brown black brown gold)
1x 470nF Ceramic Capacitor
5x 100nF Ceramic Capacitor
Technical Specifications:
Measures transmitter RF Power from 1nW to 2W (50W with 40dB attenuator) / -66.6dBm to 33dBm Auto-range RF Wattage Measurement: nW, uW, mW and W Frequency Input: 0-500MHz Self-powered by USB port Can measure higher RF power with addition of simple 10-40dBm resistor attenuator
AD8307 USB 0-500MHz RF Power Meter
Measurement of transmitter output RF power has never been easier and more precise. AD8307 USB 0-500MHz RF Power Meter allows to measure the power of transmitters from 1nW to 2W / 50W with 40dB attenuator. Output is displayed in dBm, Watts (nW, uW, mW and W range) as well as input voltage. USB RF Power Meter is based on popular AD8307 watt meter IC and PIC18F2550 microcontroller. Instead of using LCD display module the meter connects to a PC via USB port and displays measurements on a computer via USB RF Power Meter software. The software settings can be changed to use 10-50dBm attenuator and thus allowing to measure RF power higher than 2W.
AD8307 RF Power Meter Probe
AD8307 RF Power Meter Probe is used to measure the strength of RF power and may be mounted in a small metal enclosure. To measure output RF power of transmitter connect AD8307 probe input directly to the output of your transmitter (antenna output). AD8307 probe should be connected to USB IO Board by using three wire cable. The three wires provide power for the probe that is drawn from USB port through USB IO Board, ground wire and output that connects to PIC18F2550’s PIN2 (A0).
USB IO Board
USB IO Board is used to sample voltage from AD8307 chip and pass the information in a digital format to a PC via USB port. The board consists of very few components; mainly PIC18F2550 microcontroller, standard USB Type B connector, breadboard compatibille PCB, 20MHz crystal resonator, two capacitors and two resistors.
20dB / 40dB RF Attenuators
RF attenuator is a simple resistor divider that allows AD8307 RF Power Meter to measure higher RF power than 2W. Two RF attenuator versions have been presented below. 20dB RF attenuator increases measurment range up to 20W while 40dB RF attenuator increases measurment range up to 50W. After connecting attenuator to RF Probe, remember to change attenuator value in Power Meter software from 0 to 20/40. All resistors are 1% metal film type with 1/4W rating. 40dB attenuator can measure RF power that is greater than 50W after replacing 1/4W resistors with higher wattage rating such as 1-3W.