Rf decibel power meter description.
Rf power meter schematic.
The circuit diagram of the decibel meter in figure 1 stands out by its simplicity which is due to the type ad8307 monolithic demodulating logarithmic amplifier ic1 from analog devices.
Here is yet another ad8307 based rf power meter which adds an opamp to produce a dc output voltage of 1mv dbm e g 0mv 0dbm 10mv 10dbm etc.
These take a small amount of power which is rectified and passed to a meter to provide a reading.
The power meter the cornerstone of the power meter circuit shown in figure 1 is an analog devices ad8307an logarithmic amplifier ic u1.
Although you might consider the.
The schematic diagram of the peak detector circuit connected between the rf power detector board and the display board is shown below.
Here is the schematic diagram of this rf strength meter circuit.
50 mhz frequency counter voltage meter swr pwr indicator circuit schematic schema wiring diagram diy project schaltbild shema.
This circuit is another radio frequency rf field strength meter similar with our previous field strength meter circuit but with lower supply voltage only a single cell 1 5v battery.
Rf power meter components forward reflected sensor meter rf in rf out x x directional coupler.
Pictures of a homebrew 2 4 ghz rf power meter swr meter.
To use turn on transmitter and meter.
The diagram shows a simple swr bridge or swr reflectometer circuit.
The circuit uses a dual op amp as a simple peak detector with the capacitor c1 holding the peak voltage between pulses.
It has two directional coupler lines running parallel to the main through rf power line.
Rf programmable attenuators digital step attenuators from mini circuits provide precise level control from 0 to 120 db for applications up to 40 ghz with easy connection via usb ethernet rs232 and spi interfaces.
The measurand quantity to be measured is applied to pin 8 inp of ic1 via input socket k1 and capacitor c1.
Swr reflectometer bridge circuit.
Swr bridge covering hf to vhf circuit schematic schema wiring diagram diy project schaltbild shema.
It is possible to make high frequency rf power swr standing wave ratio meters using homebrew directional couplers and other easily available parts.
The rf power in dbm can be read directly with a multimeter and i ve found it particularly useful for measuring rf filter response when combined with a sweep generator and an oscilloscope.
Adjust c1 for peak reading.
A tap circuit supplements the power meter extending the upper limit by 40 db allowing measurement of up to 100 w 50 dbm.
Qrp circuits for measuring rf voltage rf current rf power swr circuit schematic schema wiring diagram diy project schaltbild shema.
It is even possible to use the directional coupler and detector diodes from an old cellular phone.