Summary: <p>We sit down with Phil Gresock to talk about the basics of RF for “DC plebians.” Learn about RF designs, radio frequencies, RADAR, GPS, and RF terms you need to know in today’s electrical <a href="https://eestalktech.com">engineering podcast</a>!</p> <div class="jetpack-video-wrapper"></div> <audio class="wp-audio-shortcode" id="audio-1775-14" style="width: 100%;"><a href="https://eestalktech.com/wp-content/uploads/2017/11/intro-to-rf-ees-talk-tech-electrical-engineering-podcast-21.mp3">https://eestalktech.com/wp-content/uploads/2017/11/intro-to-rf-ees-talk-tech-electrical-engineering-podcast-21.mp3</a></audio> <p> </p> <h2>Agenda:</h2> <h2>RF stands for radio frequency</h2> <p>00:40 Phil Gresock was an RF application engineer</p> <p>1:15 Everything is time domain, but a lot of RF testing tools end up being frequency domain oriented</p> <p>2:15 Think about radio, for example. A tall radio tower isn’t actually one big antenna!</p> <p>3:50 Check out the FCC <a href="https://www.ntia.doc.gov/files/ntia/publications/2003-allochrt.pdf">spectrum allocation chart</a></p> <p>4:10 RF communication is useful when we want to communicate and it doesn’t make sense to run a cable to what we’re communicating to.</p> <p>4:50 When you tune your radio to a frequency, you are tuning to a center frequency. The center frequency is then down converted into a range</p> <p>6:30 Check out Mike’s blog on <a href="https://community.keysight.com/community/keysight-blogs/oscilloscopes/blog/2017/06/20/how-signal-modulation-works">how signal modulation works</a>:</p> <p>7:00 Communication is just one use case. RADAR also is an RF application.</p> <p>8:10 The principles between RF and DC or digital use models are very similar, but the words we use tend to be different.</p> <p><a href="http://literature.cdn.keysight.com/litweb/pdf/5989-5733EN.pdf">Bandwidth</a> for oscilloscopes means DC to a frequency, but for RF it means the analysis bandwidth around a center frequency</p> <p>9:22 Cellular and FCC allocation chart will talk about different “channels.”</p> <p>Channel in the RF world refers to frequency ranges, but in the DC domain it typically refers to a specific input.</p> <p>10:25 Basic RF block diagram:</p> <p>First, there’s an input from an FPGA or data creating device. Then, the signal gets mixed with a local oscillator (LO). That then connects to a transmission medium, like a fiber optic cable or through the air.</p> <p>Cable TV is an RF signal that is cabled, not wireless.</p> <p>Then, the transmitted signal connects to an RF downcoverter, which is basically another mixer, and that gets fed into a processing block.</p> <p>13:50 Tesla created a <a href="https://en.wikipedia.org/wiki/Radio_control">remote control boat </a>and pretended it was voice controlled.</p> <p>15:30 Does the military arena influence consumer electronics, or does the consumer electronics industry influence military technology?</p> <p>16:00 GPS is a great example of military tech moving to consumer electronics</p> <p>17:00 IoT (internet of things) is also driving a lot of the technology</p> <p>18:00 The<a href="https://en.wikipedia.org/wiki/ISM_band"> ISM band</a> is unregulated!</p> <p>19:15 A router uses a regulated frequency and hops off the frequency when it’s being used for emergency communications</p> <p>20:50 RADAR, how does it work?</p> <p>22:22 To learn more about RF, check out App Note 150 here:</p> <p><a href="http://www.keysight.com/main/editorial.jspx?cc=US&lc=eng&ckey=459160&id=459160&cmpid=zzfindappnote150">http://www.keysight.com/main/editorial.jspx?cc=US&lc=eng&ckey=459160&id=459160&cmpid=zzfindappnote150</a></p> <p> </p> <p> </p> <p> </p>
