# K-Band VCO Calibration Procedure

<h2 id="bkmrk-objective" class="align-left">Objective</h2>
<p id="bkmrk-test-the-correct-fun">Measure the frequency response of the VCO and characterize it.<br></p>
<p id="bkmrk-%C2%A0"><br></p>
<h2 id="bkmrk-steps-to-follow">Steps to follow</h2>
<ul id="bkmrk-turn-on-equipment-sp">
<li>
<p>Turn on equipment</p>
<ul>
<li>Spectrum analizer</li>
<li>Power supply</li>
</ul>
</li>
<li>
<p>Configure to desired parameters</p>
<ul>
<li>Spectrum analizer
<ul>
<li>Set center frequency in the middle of VCO output band (6250MHz)</li>
<li>Set span to match the VCO output band (1400MHz)</li>
<li>Set RBW and VBW to an adecuate level</li>
</ul>
</li>
<li>Power supply
<ul>
<li>Set Voltage to 3.3V</li>
<li>Set current limit to 0.3A</li>
</ul>
</li>
</ul>
</li>
<li>
<p>Set up nucleo board and PC</p>
<ul>
<li>Make sure the proper code is loaded into the nucleo board</li>
<li>Set up PuTTy
<ul>
<li>Select the serial port terminal</li>
<li>Set Speed(baud) to 115200</li>
<li>Set data bits to 8</li>
<li>Set stop bits to 1</li>
<li>Turn off parity</li>
<li>Set flow control to XON/XOFF</li>
<li>Set COM port to the nucleo connected one</li>
</ul>
</li>
</ul>
</li>
<li>
<p>Make connections</p>
<ul>
<li>Connect the power supply to the payload:
<ul>
<li>Vcc to PoL (RED)</li>
<li>GND to GND (BLACK)</li>
</ul>
</li>
<li>Connect the DAC output to the DAC_In (GREEN)</li>
<li>Connect the spectrum analizer to the switched measuring pin (PURPLE)</li>
</ul>
<p><a href="https://wiki.nanosatlab.space/uploads/images/gallery/2023-04/top-k-band-testing-connections.PNG" target="_blank" rel="noopener"><img src="https://wiki.nanosatlab.space/uploads/images/gallery/2023-04/scaled-1680-/top-k-band-testing-connections.PNG" alt="Top_K-Band_Testing_Connections.PNG"></a></p>
<ul>
<li>Connect PC to ground (plug in the charger)</li>
<li>Connect necleo board to computer by USB</li>
</ul>
</li>
<li>
<p>Power on power supply</p>
</li>
<li>
<p>Begin the measurements procedure</p>
<ul>
<li>Enter frequency in PuTTy (begin on 5600 MHz)</li>
<li>Measure where the input signal peak is and annotate it</li>
<li>Annotate the deviation observed</li>
<li>Repeat these steps with Fvco += 50 MHz</li>
</ul>
</li>
<li>
<p>Update the VCO calibration and check it. If it&rsquo;s not correct repeat the previous step</p>
</li>
</ul>