{"id":13727,"date":"2023-06-30T23:53:31","date_gmt":"2023-06-30T23:53:31","guid":{"rendered":"https:\/\/liquidinstruments.com\/?p=13727"},"modified":"2025-12-18T00:22:29","modified_gmt":"2025-12-18T00:22:29","slug":"impedance-measurements-part-1","status":"publish","type":"post","link":"https:\/\/liquidinstruments.com\/application-notes\/impedance-measurements-part-1\/","title":{"rendered":"Impedance measurements with Moku:Go \u2013 Part 1: Resistance","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"<div class=\"wpb-content-wrapper\"><p>[vc_row][vc_column][vc_column_text]<\/p>\n<div>\n<p>This application note presents an example of making impedance measurements using the <a href=\"https:\/\/liquidinstruments.com\/products\/hardware-platforms\/mokugo\/\">Moku:Go<\/a> device. Here in Part 1, we will explore the underlying mathematical principles of measuring resistance and its accuracy using the software-defined Moku <a href=\"https:\/\/liquidinstruments.com\/products\/integrated-instruments\/frequency-response-analyzer\/\">Frequency Response Analyzer<\/a>. In <a href=\"https:\/\/liquidinstruments.com\/blog\/2023\/10\/25\/impedance-measurements-with-mokugo-part-2-inductance\/\" rel=\"noopener\">Part 2<\/a>, we expand our analysis to include inductance. In Part 3, we will explore capacitance.<\/p>\n<\/div>\n<h2>Using the Moku Frequency Response Analyzer<\/h2>\n<p style=\"font-weight: 400;\">The Moku <a href=\"https:\/\/liquidinstruments.com\/products\/integrated-instruments\/frequency-response-analyzer\/\">Frequency Response Analyzer<\/a> drives a swept sine wave on the Moku:Go device\u2019s outputs and simultaneously measures the received signal amplitude (or power) on the device\u2019s input. This can be used to measure the transfer function of a system or device under test (DUT) and thus create a plot of amplitude and phase vs. frequency, commonly referred to as a Bode plot.<\/p>\n<h3>Frequency Response Analyzer: Voltage units<\/h3>\n<div>\n<p style=\"font-weight: 400;\">To measure the impedance of a device under test (Z<sub>dut<\/sub>), we need to understand a Bode plot, which is plotted in the Frequency Response Analyzer. The Frequency Response Analyzer amplitude plot uses units of dBm, dBV<sub>pp<\/sub>, or dBV<sub>rms<\/sub>. The dBV<sub>pp<\/sub> unit mode, or decibels relative to one-volt peak-to-peak (1 V<sub>pp<\/sub>), is a convenient unit of measurement in this situation. Defined as:<\/p>\n<\/div>\n<div>\n<p><img decoding=\"async\" class=\"aligncenter wp-image-13774 size-full\" src=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-12.27.40-PM-1.png\" alt=\"The Frequency Response Analyzer amplitude plot uses units of dBm, dBVpp, or dBVrms. The dBVpp unit mode, or decibels relative to one-volt peak-to-peak (1 Vpp), is a convenient unit of measurement in this situation.\" width=\"594\" height=\"186\" srcset=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-12.27.40-PM-1.png 594w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-12.27.40-PM-1-300x94.png 300w\" sizes=\"(max-width: 594px) 100vw, 594px\" \/><\/p>\n<p>So 1 V<sub>pp<\/sub> expressed in dBV<sub>pp<\/sub> gives:<\/p>\n<p><img decoding=\"async\" class=\"aligncenter wp-image-13775 size-full\" src=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.44.45-PM.png\" alt=\"1 Vpp expressed in dBVpp gives the following: \" width=\"462\" height=\"170\" srcset=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.44.45-PM.png 462w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.44.45-PM-300x110.png 300w\" sizes=\"(max-width: 462px) 100vw, 462px\" \/><\/p>\n<\/div>\n<p>Figure 1 shows use of the Frequency Response Analyzer to generate a 1 V<sub>pp<\/sub> sine wave and with Output 1 connected via direct coax to Input 1. The resulting amplitude is of course flat across the frequency range (0-8 kHz) with an amplitude of-0.0094 dBV<sub>pp<\/sub>, very close to the calculated 0 dBV<sub>pp<\/sub>. The discrepancy equates to 0.001 V<sub>pp<\/sub> (or 0.1%).<\/p>\n<p><img decoding=\"async\" class=\"aligncenter wp-image-14054 size-full\" src=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Picture1.png\" alt=\"Frequency Response Analyzer plot of 1 Vpp driven directly into the Moku:Go input\" width=\"1022\" height=\"364\" srcset=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Picture1.png 1022w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Picture1-300x107.png 300w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Picture1-768x274.png 768w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Picture1-600x214.png 600w\" sizes=\"(max-width: 1022px) 100vw, 1022px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: center;\"><strong>Figure 1:<\/strong> Frequency Response Analyzer plot of 1 V<sub>pp<\/sub> driven directly into the Moku:Go input<\/p>\n<h3>Impedance<\/h3>\n<h4>Single-port measurement<\/h4>\n<p>With this knowledge of the Frequency Response Analyzer power units, we can now make an impedance measurement.<\/p>\n<p>In this first example, we will measure R<sub>dut<\/sub> of a simple 10 k\u03a9, 10% tolerance resistor. Because the input impedance of Moku:Go is 1 M\u03a9, we need to lower this value. We can do this by connecting a resistance in parallel with the input to ensure that the power dissipation occurs over the DUT. In this example, a 50 \u03a9 terminator resistor was connected to input one. The output load on Moku:Go is 200 \u03a9, so the effective circuit is shown in Figure 2:<\/p>\n<p><img decoding=\"async\" class=\"aligncenter wp-image-14055 size-full\" src=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/2.png\" alt=\"Effective circuit for Moku:Go\" width=\"1014\" height=\"494\" srcset=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/2.png 1014w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/2-300x146.png 300w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/2-768x374.png 768w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/2-600x292.png 600w\" sizes=\"(max-width: 1014px) 100vw, 1014px\" \/><\/p>\n<p style=\"text-align: center;\"><strong>Figure 2:<\/strong> Effective circuit for Moku:Go<\/p>\n<p>Figure 3 shows the correlating setup using a Moku:Go device and 50 \u03a9 T-piece on the input. Please note that it is important to avoid using the Oscilloscope probes to connect to the DUT, as the probes have an impedance that may alter the accuracy of your measurements.<\/p>\n<p><img decoding=\"async\" class=\"aligncenter wp-image-13779 size-full\" src=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/ImpedanceFig3.jpg\" alt=\"Single-port setup with Moku:Go\" width=\"572\" height=\"747\" srcset=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/ImpedanceFig3.jpg 572w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/ImpedanceFig3-230x300.jpg 230w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/ImpedanceFig3-300x392.jpg 300w\" sizes=\"(max-width: 572px) 100vw, 572px\" \/><\/p>\n<p style=\"text-align: center;\"><strong>Figure 3:<\/strong> Single-port setup<\/p>\n<p>The Moku:Go Frequency Response Analyzer operates up to 20 MHz, but for these resistance measurements, a plot to 10 kHz is sufficient. Figure 4 shows the Moku Frequency Response Analyzer amplitude response equal to -46.18 dBV<sub>pp<\/sub> at V<sub>in<\/sub>.<\/p>\n<p><img decoding=\"async\" class=\"aligncenter wp-image-14056 size-full\" src=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/3.png\" alt=\"Frequency Response Analyzer plot of a 10 k\u03a9 DUT (single-port)\" width=\"1008\" height=\"576\" srcset=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/3.png 1008w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/3-300x171.png 300w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/3-768x439.png 768w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/3-600x343.png 600w\" sizes=\"(max-width: 1008px) 100vw, 1008px\" \/><\/p>\n<p style=\"text-align: center;\"><strong>Figure 4:<\/strong> Frequency Response Analyzer plot of a 10 k\u03a9 DUT (single-port)<\/p>\n<p>Rearranging power equation (1) we can state:<\/p>\n<p><img decoding=\"async\" class=\"aligncenter wp-image-13781 size-full\" src=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.49.24-PM.png\" alt=\"power equation rearranged \" width=\"758\" height=\"172\" srcset=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.49.24-PM.png 758w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.49.24-PM-300x68.png 300w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.49.24-PM-600x136.png 600w\" sizes=\"(max-width: 758px) 100vw, 758px\" \/><\/p>\n<p>With measured Pdb of -46.18 dBV<sub>pp<\/sub>, we calculate V<sub>in<\/sub> = 4.91 mV.<\/p>\n<p>The resistor divider of R<sub>dut<\/sub> and the Moku inputs and output in Figure 2 gives us:<\/p>\n<p><img decoding=\"async\" class=\"aligncenter wp-image-13782 size-full\" src=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.50.59-PM.png\" alt=\"With measured Pdb of -46.18 dBVpp, we calculate Vin = 4.91 mV\" width=\"722\" height=\"142\" srcset=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.50.59-PM.png 722w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.50.59-PM-300x59.png 300w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.50.59-PM-600x118.png 600w\" sizes=\"(max-width: 722px) 100vw, 722px\" \/><\/p>\n<p>Where R<sub>in<\/sub> is the equivalent parallel resistance:<\/p>\n<p><img decoding=\"async\" class=\"aligncenter wp-image-13783 size-full\" src=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.51.52-PM.png\" alt=\"Equation where Rin is the equivalent parallel resistance\" width=\"732\" height=\"302\" srcset=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.51.52-PM.png 732w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.51.52-PM-300x124.png 300w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.51.52-PM-600x248.png 600w\" sizes=\"(max-width: 732px) 100vw, 732px\" \/><\/p>\n<p>Solving gives R<sub>dut<\/sub> = 9933 \u03a9.<\/p>\n<p>A digital voltmeter (DVM) reading of this resistor showed 9970 \u03a9.<\/p>\n<p>So from this simple, one-resistor measurement, we can conclude Moku:Go is accurate within 37 \u03a9 (&lt;1%).<\/p>\n<h4>Low-impedance measurement<\/h4>\n<p>The previous example used a standard 10% tolerance resistor. We are now interested in measuring a lower impedance to a high level of accuracy. To do this, we will use a 100 \u03a9, 0.005% tolerance high-precision resistor. Using the previous method, we obtain a power magnitude plot (Figure 5).<\/p>\n<p><img decoding=\"async\" class=\"aligncenter wp-image-14057 size-full\" src=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/4.png\" alt=\"Frequency Response Analyzer plot of 100 \u03a9, 0.005% (single-port)\" width=\"984\" height=\"546\" srcset=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/4.png 984w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/4-300x166.png 300w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/4-768x426.png 768w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/4-600x333.png 600w\" sizes=\"(max-width: 984px) 100vw, 984px\" \/><\/p>\n<p style=\"text-align: center;\"><strong>Figure 5:<\/strong> Frequency Response Analyzer plot of 100 \u03a9, 0.005% (single-port)<\/p>\n<p>Applying the measured power of -16.89 dBV<sub>pp<\/sub> to equations (2) &amp; (5) we calculate R<sub>dut<\/sub> to be 99.33 \u03a9. This agrees with the known value, but we can do better with a two-port measurement.<\/p>\n<h4>Two-port measurement<\/h4>\n<p>To further improve our result, we need to account for the loading of the DUT on the Moku output.<\/p>\n<p>We can accomplish this with a two-port measurement utilizing the second input port of the Moku device to observe the applied signal level. The configuration of this setup is shown in Figure 6.<\/p>\n<p><img decoding=\"async\" class=\"aligncenter wp-image-14058 size-full\" src=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/5.jpg\" alt=\"Two-port Moku:Go configuration\" width=\"552\" height=\"462\" srcset=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/5.jpg 552w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/5-300x251.jpg 300w\" sizes=\"(max-width: 552px) 100vw, 552px\" \/><\/p>\n<p style=\"text-align: center;\"><strong>Figure 6:<\/strong> Two-port configuration<\/p>\n<p>Please note that a parallel resistance is still required for input 1. Here, we will continue using the 50 \u03a9 terminator resistor. To ensure minimal loading of the output, Input 2 remains at a high impedance of 1 M\u03a9.<\/p>\n<p>Figure 7 shows that R<sub>1<\/sub> is the same as the equivalent resistance calculated as the input resistance in the single-port example.<\/p>\n<p><img decoding=\"async\" class=\"aligncenter wp-image-14061 size-full\" src=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/6-1.jpg\" alt=\"Two-port equivalent circuit with Moku:Go\" width=\"972\" height=\"480\" srcset=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/6-1.jpg 972w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/6-1-300x148.jpg 300w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/6-1-768x379.jpg 768w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/6-1-600x296.jpg 600w\" sizes=\"(max-width: 972px) 100vw, 972px\" \/><\/p>\n<p style=\"text-align: center;\"><strong>Figure 7:<\/strong> Two-port equivalent circuit<\/p>\n<p>We can derive R<sub>dut<\/sub> in figure 7, from Ohm\u2019s law:<\/p>\n<p><img decoding=\"async\" class=\"aligncenter wp-image-13787 size-full\" src=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.54.12-PM.png\" alt=\"Derived Rdut in figure 7, from Ohm\u2019s law\" width=\"726\" height=\"168\" srcset=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.54.12-PM.png 726w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.54.12-PM-300x69.png 300w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.54.12-PM-600x139.png 600w\" sizes=\"(max-width: 726px) 100vw, 726px\" \/><\/p>\n<p><img decoding=\"async\" class=\"aligncenter wp-image-13788 size-full\" src=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.54.54-PM-1.png\" alt=\"Derived Rdut in figure 7, from Ohm\u2019s law\" width=\"724\" height=\"154\" srcset=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.54.54-PM-1.png 724w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.54.54-PM-1-300x64.png 300w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.54.54-PM-1-600x128.png 600w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><\/p>\n<p>Substitute (7) into (6):<\/p>\n<p><img decoding=\"async\" class=\"aligncenter wp-image-13789 size-full\" src=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.55.57-PM.png\" alt=\"derived Rdut in figure 7, from Ohm\u2019s law\" width=\"724\" height=\"290\" srcset=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.55.57-PM.png 724w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.55.57-PM-300x120.png 300w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.55.57-PM-600x240.png 600w\" sizes=\"(max-width: 724px) 100vw, 724px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p>We set up this two-port measurement with our tight tolerance 100 \u03a9, 0.005% resistor and captured the Moku Frequency Response Analyzer plot in Figure 8.<\/p>\n<p><img decoding=\"async\" class=\"aligncenter wp-image-14059 size-full\" src=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/7.png\" alt=\"two-port measurement with tight tolerance 100 \u03a9, 0.005% resistor and Moku Frequency Response Analyzer interface plot\" width=\"972\" height=\"538\" srcset=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/7.png 972w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/7-300x166.png 300w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/7-768x425.png 768w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/7-600x332.png 600w\" sizes=\"(max-width: 972px) 100vw, 972px\" \/><\/p>\n<p style=\"text-align: center;\"><strong>Figure 8:<\/strong> 100 \u03a9 (two-port)<\/p>\n<p>Note, we have used the Frequency Response Analyzer\u2019s math channel to produce V<sub>2<\/sub>\/V<sub>1<\/sub> in orange. This is very quick and simple to configure using the Frequency Response Analyzer interface.<\/p>\n<p>From (8), we see that the R<sub>dut<\/sub> can be calculated simply from the V<sub>2<\/sub>:V<sub>1<\/sub> voltage ratio.<\/p>\n<p>The math channel has calculated the power ratio as 9.526 dBV<sub>pp<\/sub>. Thus, the voltage ratio is:<\/p>\n<p><img decoding=\"async\" class=\"aligncenter wp-image-13791 size-full\" src=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.57.54-PM.png\" alt=\"voltage ratio with the math channel calculated to the power ratio as 9.526 dBVpp\" width=\"498\" height=\"182\" srcset=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.57.54-PM.png 498w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.57.54-PM-300x110.png 300w\" sizes=\"(max-width: 498px) 100vw, 498px\" \/><\/p>\n<p>So, with R<sub>1<\/sub> equal to 50 \u03a9, we can apply (8) to obtain R<sub>dut<\/sub> = 99.72 \u03a9.<\/p>\n<p>We can now apply this two-port method to the original 10 k\u03a9 \/ 20% resistor; Figure 9 shows the Frequency Response Analyzer response.<\/p>\n<p><img decoding=\"async\" class=\"aligncenter wp-image-14060 size-full\" src=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/8.png\" alt=\"Frequency Response Analyzer response with two-port method to the original 10 k\u03a9 \/ 20% resistor\" width=\"968\" height=\"530\" srcset=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/8.png 968w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/8-300x164.png 300w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/8-768x420.png 768w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/8-600x329.png 600w\" sizes=\"(max-width: 968px) 100vw, 968px\" \/><\/p>\n<p style=\"text-align: center;\"><strong>Figure 9:<\/strong> 10 k\u03a9 (two-port)<\/p>\n<p>Using our established formula, the power ratio of 46.04 dBV<sub>pp<\/sub> gives R<sub>dut<\/sub> = 9976 \u03a9 two-port method leads to a useful improvement from the measured 9333 \u03a9 with the single-port method. This proves that the two-port method allows for a higher degree of accuracy.<\/p>\n<h2>Summary<\/h2>\n<p>The Moku:Go Frequency Response Analyzer can be used to make impedance measurements and determine, to a &lt;1% accuracy, the value of a resistance.<\/p>\n<p><img decoding=\"async\" class=\"alignnone wp-image-13793\" src=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.59.53-PM.png\" alt=\"The Moku:Go Frequency Response Analyzer summary\" width=\"300\" height=\"143\" srcset=\"https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.59.53-PM.png 696w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.59.53-PM-300x143.png 300w, https:\/\/liquidinstruments.com\/wp-content\/uploads\/2023\/06\/Screenshot-2023-06-30-at-1.59.53-PM-600x286.png 600w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/p>\n<p>The two-port method allows for the loading of the DUT.<\/p>\n<h3>Using Python<\/h3>\n<p>You can also automate your testing and impedance measurements with the Moku through <a href=\"https:\/\/apis.liquidinstruments.com\/\">APIs<\/a>. In this example, a <a href=\"https:\/\/apis.liquidinstruments.com\/starting-python.html#requirements\">Python<\/a> script was created to conduct single-port and two-port measurements that you can apply to any Moku device with the alteration of a few parameters, which are noted throughout the script.<\/p>\n<p>Find the code for the single-port and two-port measurements <a href=\"https:\/\/knowledge.liquidinstruments.com\/en_US\/meauring-impedance-with-mokugo-part-1\" rel=\"noopener\">here<\/a>.<\/p>\n<h2>Questions or comments?<\/h2>\n<p>Contact us at <a href=\"mailto:support@liquidinstruments.com\">support@liquidinstruments.com<\/a>.<\/p>\n<\/div>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"<p>[vc_row][vc_column][vc_column_text] This application note presents an example of making impedance measurements using the Moku:Go device. Here in Part 1, we will explore the underlying mathematical principles of measuring resistance and its accuracy using the software-defined Moku Frequency Response Analyzer. In Part 2, we expand our analysis to include inductance. In Part 3, we will explore [&hellip;]<\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"author":40,"featured_media":12514,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"content-type":"","footnotes":""},"categories":[5],"tags":[315],"class_list":["post-13727","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-application-notes","tag-controlcharacterization","site-category-frequency-response-analyzer","site-category-mokugo","site-category-oscilloscpe","site-category-python"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v27.0 (Yoast SEO v27.0) - https:\/\/yoast.com\/product\/yoast-seo-premium-wordpress\/ -->\n<title>Impedance Measurement with Moku:Go - Resistance | Liquid Instruments<\/title>\n<meta name=\"description\" content=\"Master impedance measurement resistance with a Frequency 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