Introduction: UHF Spectrum Analyzer

What is A spectrum analyzer: (wikipedia)

A spectrum analyzer measures the magnitude of an input signal versus frequency within the full frequency range of the instrument. The primary use is to measure the power of the spectrum of known and unknown signals. The input signal that a spectrum analyzer measures is electrical; however, spectral compositions of other signals, such as acoustic pressure waves and optical light waves, can be considered through the use of an appropriate transducer. Optical spectrum analyzers also exist, which use direct optical techniques such as a monochromator to make measurements.

So i will show you how to build one. I'm using si4432 RF module. as datasheet said it respond to 200mhz to 900mhz radio frequency.

What you need for this:

1. A si4432 module.

2. Atmega8

3. Pl3203 Serial to USB convertor

4. some smd resistor and cap.(see the photos)

Step 1: Step 1: Print the PCB and Mount Component

first download this pcd file. I designed it by Altium Designer. Print it and start montage.

you need to solder atmega8 and crystal first. because SPI interface is used to communicate with si4432, you must program the atmega8 then solder the si4432.

Step 2: Step 2 : Program the Board.

since I'm using atmega8 , set the board type to arduino NG in arduino tools tab. then set the processor to ATMEGA8

compile the code and program the board.

after this you can solder si4432. use 30 or 40 watt soldering iron. and remember dont damage the module! a flux will be helpful.

Step 3: Step 3: PC App.

download attached above and unzip it.

run RF22SpecScan. Set COM port. (if your pl2303 not recognized you need to install driver)

Press connect. and ENJOY!