The Amp Hour Electronics Podcast

Chris Gammell and Dave Jones' voices span the chasm of thousands of miles each and every week to speak to each other and industry experts about where the field of electronics is moving. Whether it be a late breaking story about a large semiconductor manufacturer, a new piece of must-have test equipment or just talking through recent issues with their circuit designs, Chris and Dave try to make electronics more accessible for the listeners. Most importantly, they try and make the field of electronics more fun. Guests range from advanced hobbyists working on exciting new projects up through C-level executives at a variety of relevant and innovative companies. Tune in to learn more about electronics and then join the conversation! Visit The Amp Hour website for our back catalog of 150+ episodes.

https://theamphour.com

subscribe
share






#446 – An Interview with Pete Bevelacqua


Welcome, Pete Bevelacqua of Antenna-Theory.com!

This episode is brought to you by our sponsor Rohde & Schwarz. They just announced an industry first: complete solutions with all the upgrades up front—for one price. Now through December 31, save up to $10,000 on Rohde & Schwarz solution packages that come with fully loaded test & measurement instruments, right from the start. For more information about their latest product offering, check out AskAnEngineer.us

  • Chris first met Pete when he was giving a talk at HDDG about a custom made VNA
    • 0h 0m 55s
  • Pete has been an antenna designer at Boeing, Apple, Nest
    • 0h 1m 16s
  • Pete got started in this because he really liked Electricity and Magnetism classes.
    • 0h 2m 12s
  • “Do I come out [of the class] and know how to put an antenna in a phone?” (answer: no)
    • 0h 3m 4s
  • Pete studied with Dr Bilanas at ASU
    • 0h 3m 20s
  • Convex optimization program
    • 0h 4m 12s
  • Used a lot in signal processing
    • 0h 5m 38s
  • Compared to linear optimizations
    • 0h 6m 29s
  • Boeing wanted to put 20 antennas on a plane
    • 0h 7m 37s
  • DC to daylight
    • 0h 8m 20s
  • Starting with a specific problem
    • 0h 9m 43s
  • “I want to put a bluetooth antenna in my device”
    • 0h 9m 51s
  • Start from a place of practicality
    • 0h 11m 16s
  • Do not make anything hard that doesn’t need to be hard
    • 0h 11m 32s
  • The one piece of math you need to know: the lowest frequency you’re using
    • 0h 12m 52s
  • Half wavelength for GPS is 3.5 inches
    • 0h 13m 13s
  • Efficiency is how much you’re putting in vs what you get out
    • 0h 13m 30s
  • Everything in RF is dB
    • 0h 14m 49s
  • …except for the antenna
    • 0h 15m 13s
  • “This meeting is 3dB too long”
    • 0h 16m 35s
  • Didn’t design antennas at Boeing because they didn’t need them to be custom/integrated
    • 0h 18m 53s
  • Directionality of antennae
    • 0h 21m 6s
  • “Do you want a high gain antenna?”
    • 0h 21m 12s
  • Gain specifically is the efficiency (in dB) plus the directivity (in dB)
    • 0h 21m 52s
  • FCC matters for consumer. If you have a directional antenna and it’s out of spec, you’ll need to take the overall power down
    • 0h 23m 7s
  • Effective Isotropic Radiated Power (EIRP) = conducted power + antenna gain
    • 0h 24m 0s
  • dDm is milliwatts of power
    • 0h 24m 59s
  • RF and antenna teams are different at hardware companies.
    • 0h 26m 6s
  • RF team assumes a 50 ohm antenna. The antenna team assumes a 50 ohm driver.
    • 0h 27m 7s
  • Went from Boeing to Apple
    • 0h 28m 7s
  • Consumer electronics and how it works
    • 0h 29m 3s
  • Industrial design team starts the process for look, feel and materials.
    • 0h 29m 10s
  • Mockup or simulation
    • 0h 31m 36s
  • Integration and understanding what will be interfering
    • 0h 31m 58s
  • Simulation is HFSS and CST
    • 0h 33m 4s
  • Pete isn’t big on simulating
    • 0h 33m 16s
  • Some people don’t simulate at all
    • 0h 33m 57s
  • Not that many types of antennas
    • 0h 35m 3s
  • Hybrids of dipoles
    • 0h 36m 7s
  • VNA
    • 0h 36m 21s
  • VSWR
    • 0h 36m 37s
  • VNA just tells you it is matched, not that it’s radiating
    • 0h 37m 1s
  • Once it’s matched you go about measuring its efficiency by putting it in an anechoic chamber
    • 0h 37m 42s
  • Dealing with multiple frequencies
    • 0h 38m 30s
  • GPS, Bluetooth, Wifi, Cellular
    • 0h 38m 45s
  • Cellular bands
    • 0h 39m 5s
  • Antennas are not meant to reject anything, that’s the job of the filters
    • 0h 40m 20s
  • 1850 (MHz) spectrum in cellular
    • 0h 40m 35s
  • “The ground in your PCB is part of your antenna”
    • 0h 44m 20s
  • How a flat antenna can create a unidirectional radiation
    • 0h 46m 27s
  • Omnidirectional is actually a donut pattern
    • 0h 46m 46s
  • For lower cellular frequencies, the phone is shorter than half the antenna
    • 0h 47m 33s
  • Explaining the polarization without looking
    • 0h 48m 49s
  • “The more volume you have the more bandwidth you have”
    • 0h 50m 34s
  • Fixing things with an exacto knife
    • 0h 52m 34s
  • Choking the lines allows you to select the frequencies
    • 0h 54m 5s
  • You start testing cert right away
    • 0h 55m 23s
  • Building your own VNA (talk at HDDG)
    • 0h 56m 41s
  • Went to Maker Faire, saw someone building a VNA
    • 0h 57m 58s
  • Need a bidirectional coupler
    • 1h 0m 9s
  • Need a frequency synthsizer
    • 1h 1m 8s
  • Coupler has directivity
    • 1h 2m 24s
  • Reflected comes back and you can measure with a chip
    • 1h 3m 11s
  • Got the Chazwazza (VNA project) on kickstarter, but the demand wasn’t there
    • 1h 4m 0s
  • The unit operates from 400 MHz to 2.7 GHz
    • 1h 5m 4s
  • Super light, especially compared to commercial equipment
    • 1h 5m 16s
  • After VNAs, testing chambers are also useful
    • 1h 6m 36s
  • Size of the chamber is a function of the wavelength
    • 1h 6m 54s
  • Pete’s current project is putting a working on putting a rocket in a balloon
    • 1h 7m 56s
  • Check out more of Pete’s work at Antenna-theory.com
    • 1h 9m 53s


fyyd: Podcast Search Engine
share








 June 10, 2019  n/a