Arduino antenna analyzer for HF bands

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Pocket Arduino Nano 160 to 6m band VNA antenna analyzer based on AD9850 module for field days. Powered from 9V PP3 battery.

Influenced by

• http://ra4nal.qrz.ru/vna.shtml
• https://hamprojects.wordpress.com/2016/02/21/hf-arduino-vna-english-version/

Introduction

Pocket Arduino Nano based antenna VNA analyzer / plotter can be used to measure antenna SWR from 160m band up to 6m band, real/complex impedance, return loss (s11), draw SWR chart, draw impedance chart.

Next peripherals are in use:

• Nokia 5110 screen, PCD8544 - https://www.sparkfun.com/datasheets/LCD/Monochrome/Nokia5110.pdf
• AD9850 clock generator - http://www.analog.com/media/en/technical-documentation/data-sheets/AD9850.pdf
• SGA3386 based amplifier - https://www.rf-microwave.com/datasheets/4152_Sirenza-Microdevices_SGA-3386_01.pdf
• AD8302 gain and phase detector - http://www.analog.com/media/en/technical-documentation/data-sheets/AD8302.pdf
• Reflectometer and attenuators as per - https://hamprojects.wordpress.com/2016/02/21/hf-arduino-vna-english-version/
• Rotary encoder

Building:

Use platformio to build and upload.

Supported operations:

• Details screen - shows various numeric parameters, such as forward/reflected signals, current frequency/band. By rotating rotary encoder user can change the frequency. By short press - change the band, by long press go to next screen.
• Real time SWR graph screen - shows partially updated SWR plot, plot is updated while user is changing the frequency using encoder, plot is shifted left or right depending on frequency change direction.
• Frequency sweep screen - shows complete SWR plot, which is updated approximately every second.
• Real time impedance graph screen - shows real and imaginary part of impedance graphs on the same screen, partical graph update while user is changing frequency with rotary encoder.
• Impedance sweep screen - impedance graph is updated every second periodically.
• Settings screen - enables user to change frequency step, which affects both rotary encoder changes and sweep screen, screen contrast, perform calibration.