RF Signals - Revision history

Bsboggs at 18:46, 11 January 2022

2022-01-11T18:46:45Z

Aplstudent at 18:09, 30 March 2016

2016-03-30T18:09:17Z

Aplstudent at 17:39, 30 March 2016

2016-03-30T17:39:23Z

Aplstudent: /* Mixers */

2016-03-10T00:54:25Z

‎Mixers

Aplstudent: /* Mixers */

2016-03-10T00:53:39Z

‎Mixers

Aplstudent: /* Mixers */

2016-03-10T00:53:04Z

‎Mixers

Aplstudent: /* Mixers */

2016-03-10T00:24:06Z

‎Mixers

Aplstudent: /* Splitters */

2016-03-10T00:08:12Z

‎Splitters

Aplstudent: /* Mixers */

2016-03-09T23:26:49Z

‎Mixers

Aplstudent: /* Splitters */

2016-03-08T23:39:46Z

‎Splitters

@@ Line 5: / Line 5: @@
 For this module, you will need
 <ul>
-<li> Rigol DG1022 Function Generator</li>
+<li> Rigol DG1022 Function Generator (or similar)</li>
-<li> Rigol DS1102E Oscilloscope </li>
+<li> Rigol DS1102E Oscilloscope (or similar)</li>
 <li> Micro-circuits ZAD-1 RF mixer</li>
 <li> A selection of BNC cables</li>

← Older revision		Revision as of 18:09, 30 March 2016
Line 187:		Line 187:

	To look at filtering, we will use a mixer for frequency up-conversion. So, attach channel 2 (5MHz, 0.25V amplitude) to the LO port of the mixer, Channel 1 (4MHz, 0.25V amplitude)		To look at filtering, we will use a mixer for frequency up-conversion. So, attach channel 2 (5MHz, 0.25V amplitude) to the LO port of the mixer, Channel 1 (4MHz, 0.25V amplitude)
−
−	~~== Switches ==~~
−
−
−
−	~~Topics~~
−	~~<ul>~~
−	~~<li>Measuring RF power</li>~~
−	~~<li>Termination and impedance matching</li>~~
−	~~<li>Attenuation and filtering</li>~~
−	~~<li>Splitters, mixers, and switches</li>~~
−	~~</ul>~~

@@ Line 16: / Line 16: @@
 == Measuring RF Power ==
-Connect the output of channel 1 of the function generator through the terminator (set to 50ohm) to channel 1 of the function generator.
+Connect the output of channel 1 of the function generator through the terminator (set to 50ohm) to channel 1 of the oscilloscope.
 <ol>
@@ Line 23: / Line 23: @@
 <li> Use the scope's measure function (or the scope's cursor) to get the amplitude of the wave. Is it what you expect? What is the amplitude if you remove the terminator? Does that make sense?</li>
 <li> Use the math menu to create a fourier transform of the signal. With the cursor, does the frequency the scope reads match what the setting from the scope? If it doesn't, why do you think that might be?</li>
 </ol>

@@ Line 158: / Line 158: @@
 Using the mixer as you have above is effectively doing a <b>heterodyne</b> measurement on the signal. A heterodyne measurement takes two signals with different frequencies and measures the frequency difference and sum between them. This is a common technique in optics experiments (although often the sum of two frequencies for optical signals is well beyond the limits of a photo-detector).
-There is a another technique called a <b>homodyne</b> measurement, which uses the same (hence, <i>homo</i>dyne) signal for both the LO signal and the RF/IF signal, although, typically something has been done to the RF/IF signal before the mixing process. Let's see why this is useful.
+There is a another technique called a <b>homodyne</b> measurement, which uses the same (hence, <i>homo</i>dyne) signal for both the LO signal and the RF/IF signal after something has been done to the RF signal so we actually get a frequency difference. Let's see why this is useful.
 <ol start=13>

@@ Line 156: / Line 156: @@
-Using the mixer as you have above is effectively doing a <i>heterodyne</i> measurement on the signal. A heterodyne measurement takes two signals with different frequencies and measures the frequency difference and sum between them. This is a common technique in optics experiments (although often the sum of two frequencies for optical signals is well beyond the limits of a photo-detector).
+Using the mixer as you have above is effectively doing a <b>heterodyne</b> measurement on the signal. A heterodyne measurement takes two signals with different frequencies and measures the frequency difference and sum between them. This is a common technique in optics experiments (although often the sum of two frequencies for optical signals is well beyond the limits of a photo-detector).
-There is a another technique called <i>homodyne</i> detection, which uses the same (hence, <i>homo</i>dyne) signal for both the LO signal and the RF/IF signal., although, typically something has been done to the RF/IF signal before the mixing process. Let's see why this is useful.
+There is a another technique called a <b>homodyne</b> measurement, which uses the same (hence, <i>homo</i>dyne) signal for both the LO signal and the RF/IF signal, although, typically something has been done to the RF/IF signal before the mixing process. Let's see why this is useful.
-<ol start=10>
+<ol start=13>
 <li> Use the mixer as a down converter and look at a 6MHz LO and 3MHz RF signal on channel 1 of the oscilloscope (including looking at the fourier transform</li>
 <li> Use a splitter to make a copy of a 3MHz, 1V amplitude signal from channel 1 of the function generator.</li>

← Older revision		Revision as of 00:24, 10 March 2016
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		+	Using the mixer as you have above is effectively doing a <i>heterodyne</i> measurement on the signal. A heterodyne measurement takes two signals with different frequencies and measures the frequency difference and sum between them. This is a common technique in optics experiments (although often the sum of two frequencies for optical signals is well beyond the limits of a photo-detector).

	Homodyne and Heterodyne Mixing		Homodyne and Heterodyne Mixing

@@ Line 92: / Line 92: @@
 <li> Estimate the amplitudes of the two waves on the oscilloscope. How doe they compare to the input amplitude from the function generator? Why do you think they are related this way?</li>
 <li> Estimate any phase difference between the two signals on the oscilloscope. How does that phase difference compare to the phase difference listed in the data sheet for the splitter?</li>
 </ol>

← Older revision		Revision as of 23:26, 9 March 2016
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	</ol>		</ol>

		+
		+
		+
		+	Homodyne and Heterodyne Mixing

	== Attenuation and Filtering ==		== Attenuation and Filtering ==

← Older revision		Revision as of 23:39, 8 March 2016
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	== Splitters ==		== Splitters ==

		+	Splitters are fairly straight forward as they just split an RF signal into two outputs.
		+
		+	<ol>
		+	<li>Plug the output of channel 1 of the function generator into the S port of the splitter. Connect the two channels of the oscilloscope to outputs 1 and 2 of the splitter (make sure you match impedance appropriately).</li>
		+	<li> Set the output of channel 1 to 10Mhz and a 1V amplitude.</li>
		+	<li> What is the frequency of each wave on the oscilloscope? Does it agree with your 10MHz input? If it doesn't, why not?</li>
		+	<li> Estimate the amplitudes of the two waves on the oscilloscope. How doe they compare to the input amplitude from the function generator? Why do you think they are related this way?</li>
		+	<li> Estimate any phase difference between the two signals on the oscilloscope. How does that phase difference compare to the phase difference listed in the data sheet for the splitter?</li>
		+	</ol>

	== Mixers ==		== Mixers ==