FesZ Electronics
FesZ Electronics
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Cavity Filter Basics
#227 In this video I look at another constructive type of filters that moves from the world of lumped elements to the world of distributed elements, what I'm referring to is cavity filters. I look at some of the basic operating principles as well as some constructive types and next time I will be performing some measurements on a set of practical devices.
Filter series:
Ep1 - Intro : ua-cam.com/video/Zipbm27LoZ4/v-deo.html
Ep2 - Passive RC Filters: ua-cam.com/video/NBLCqqmvy0A/v-deo.html
Ep3 - Active RC Filters: ua-cam.com/video/FQYtOj_4kbw/v-deo.html
Ep4 - More Active RC Filters: ua-cam.com/video/H_DiGSNaFyg/v-deo.html
Ep5 - Introduction to LC Filters: ua-cam.com/video/KECCpj1Qpn0/v-deo.html
Ep6 - LC filter limitations: ua-cam.com/video/DYJkmq5xUlc/v-deo.html
Ep7 - Piezo-Electric Filters
Ep8 - Crystal Filter Measurements and Design
Ep9 - Cavity filter Basics
Further reading:
w6nbc.com/articles/duplexer.pdf
lea.hamradio.si/~s53mv/cavity/cavity.html
k5tra.net/tech%20library/filters%20-%20general/Cavity%20and%20combline%20filters,%20combiners,%20and%20duplexers/Cavity%20and%20combline%20filters,%20combiners%20and%20duplexers.pdf
Special Thanks to all my supporters on Patreon!
If you liked this video be sure to check out my other videos and you can also subscribe to be up to date with all the new ones!
If you want to support the creation of more and better videos please consider checking out: www.patreon.com/feszelectronics
Переглядів: 7 027

Відео

Crystal Filter Experiments
Переглядів 3,8 тис.21 годину тому
#226 In this video I continue looking at crystal and ceramics based piezo-electric filters, by performing some measurements and experiments on a set of filters I've previously built. I take a look at a few stand-alone filter components - like a saw filter and a ceramic resonator but also observe how a crystal ladder filter can be designed and what are some of the things to keep in mind with it....
Piezo-Electric Filters
Переглядів 4,7 тис.21 день тому
#225 In this episode I start looking at piezo-electric based components that can be used in filter circuits. Things like ceramic resonators, quartz crystals and SAW or BAW filter components can all be categorized into a wider class of piezo-electric components. I first look at what are the principles used by such a component and then continue by looking at the equivalent electrical model. Final...
Limitations of LC Filters
Переглядів 5 тис.28 днів тому
#224 In this video I look at some of the issues faced by filters build around inductors and capacitors - although a widely used type of filter, the LC filter is not a universal solution - main limitations that it faces will be the losses and thus the limited Q factor and the other big issue is the components actually keeping their values - in certain usecases, the components will just change th...
Introduction to LC Filters
Переглядів 6 тис.Місяць тому
#223 In this video I continue looking at filters by analyzing implementations that utilize reactive only passive components - inductors and capacitors. I look at the main building blocks - the exact arrangements in which individual or groups of components are commonly used but also look at specific calculation tool that makes designing filters a bit more easy. Filter series: Ep1 - Intro : ua-ca...
MORE Active RC Filters
Переглядів 3,5 тис.Місяць тому
#222 In this video I continue looking at the topic of active RC filters by first of all analyzing the All-Pass filter and then looking at some other active circuits that can be used in the building of filter. In particular I look at the negative impedance converter and the general impedance converter. After analyzing what the circuits are supposed to do, I try out some simulations to see how it...
Active RC-filter Basics
Переглядів 6 тис.2 місяці тому
#221 In this video I continue looking at filters, by exploring how the basic RC filter can be enhanced by using active, amplification, elements. I look at the various limitations that are brought on by the amplification element but also the benefits and some of the special configurations that can be implemented. Active elements will allow the creation of all the types of filter response, but al...
Passive RC Filters
Переглядів 3,8 тис.2 місяці тому
#220 In this video I start looking at one of the most basic forms of filters - the ones implemented as resistor-capacitor networks. Contrary to their apparent simplicity, these filters can be made to have a wide variety of response shapes and are usually used in low frequency applications. Filter series: Ep1 - Intro : ua-cam.com/video/Zipbm27LoZ4/v-deo.html Ep2 - Passive RC Filters: ua-cam.com/...
Intro to Filters
Переглядів 10 тис.2 місяці тому
#219 This video is the first in a longer series dedicated to looking at electronic filters. In this episode I focus on some of the basics regarding filtrs, look at the various types of filters, their characteristic responses and how the response can vary based on the chosen components. I will also be looking into some of the terms associated with filters regarding their amplitude but also phase...
Looking at Pulse Width Modulation and Pulse Frequency Modulation
Переглядів 4,2 тис.3 місяці тому
#218 In this video I take a look at the key differences between the main ways of modulating the drive signal of a switched mode power supply - Pulse width and Pulse frequency modulation. Both types of modulation end up doing the same thing - regulating the output voltage of the supply, but they each have their specific advantages and drawbacks. More on Power supplies: PSU Static Output: ua-cam....
Skin Effect and Proximity Effect
Переглядів 19 тис.3 місяці тому
#217 In this video I look at the basic effects that end up changing the resistance of conductors when signals of different frequency pass trough - skin effect and proximity effect. I look at the theoretical principles behind these phenomenon but also try measuring them in real life. How to setup your VNA measurements: ua-cam.com/video/X2lk-V-d9E8/v-deo.html More inductor related content: Toroid...
LTspice tutorial - simulating Frequency Dependent component Parameters
Переглядів 3,2 тис.3 місяці тому
#216 In this tutorial episode I look at how components can be modeled to have frequency dependent parameters. I first analyze the way in which the basic passive components - the resistor, capacitor and inductor can be modeled using G-sources with the Laplace function, and then I look at how the values can be made frequency dependent. Further reading: www.analog.com/en/resources/technical-articl...
How to setup your VNA measurements
Переглядів 8 тис.4 місяці тому
#215 In this video I look at some of the specific setup considerations needed when performing measurements with a VNA. In general the VNA, like any other tool, is capable of very good results but only if its used correctly. I will be looking at the various ways in which a test component can be connected based on the exact expected impedance as well as other setup considerations like external no...
Looking at Continuous and Discontinuous Conduction Mode
Переглядів 8 тис.4 місяці тому
#214 In this video I analyze and look at the main differences between the main conductions modes found in switch mode power supplies - continuous and discontinuous conduction mode. I look at what the exact difference is between the 2 modes as well as look at how the performance of the circuit is finally impacted. More on Power supplies: PSU Static Output: ua-cam.com/video/ESz64YnDEIg/v-deo.html...
Gain block RF Amplifiers - Building and Testing [2/2]
Переглядів 5 тис.4 місяці тому
#213 In this video I continue working on the gain block amplifier I simulated last time, by building it and doing some practical tests. Although its not perfect, it does provide usable performance by enhancing some of the weaker signals. Related content: Gain block RF Amplifiers - Theory and Design [1/2]: ua-cam.com/video/8myFI-tmowo/v-deo.html Gain block RF Amplifiers - Theory and Design [2/2]...
Gain block RF Amplifiers - Theory and Design [1/2]
Переглядів 29 тис.5 місяців тому
Gain block RF Amplifiers - Theory and Design [1/2]
Building INDUCTOR-CAPACITOR Baluns
Переглядів 3,3 тис.5 місяців тому
Building INDUCTOR-CAPACITOR Baluns
Analyzing Guanella Impedance Transformers
Переглядів 4,3 тис.5 місяців тому
Analyzing Guanella Impedance Transformers
The Ruthroff Impedance Transformer
Переглядів 9 тис.7 місяців тому
The Ruthroff Impedance Transformer
LTspice tutorial - Differential transmission lines
Переглядів 5 тис.7 місяців тому
LTspice tutorial - Differential transmission lines
Experiments with Transmission Line Baluns
Переглядів 2,7 тис.7 місяців тому
Experiments with Transmission Line Baluns
Transmission-Line Baluns
Переглядів 3,2 тис.8 місяців тому
Transmission-Line Baluns
Energy transfer in Baluns
Переглядів 5 тис.8 місяців тому
Energy transfer in Baluns
Voltage and Current Baluns
Переглядів 8 тис.8 місяців тому
Voltage and Current Baluns
Communication lines and baluns
Переглядів 12 тис.9 місяців тому
Communication lines and baluns
Quick look at QSPICE
Переглядів 20 тис.9 місяців тому
Quick look at QSPICE
Electronic Switches - SMPS and snubbers (2/2)
Переглядів 8 тис.9 місяців тому
Electronic Switches - SMPS and snubbers (2/2)
Electronic Switches - SMPS and snubbers (1/2)
Переглядів 15 тис.10 місяців тому
Electronic Switches - SMPS and snubbers (1/2)
About Resonant Dipoles
Переглядів 12 тис.10 місяців тому
About Resonant Dipoles
Switch Contact Protection - Testing it Out (2/2)
Переглядів 6 тис.10 місяців тому
Switch Contact Protection - Testing it Out (2/2)

КОМЕНТАРІ

  • @fotografm
    @fotografm 6 годин тому

    Excellent video ! I appreciate your clear and thorough approach. This technology cannot be replaced by SDR when power is involved eg. in a transmitter. Keep up the good work !

  • @glenmartin2437
    @glenmartin2437 10 годин тому

    Thanks.

  • @juliano8603
    @juliano8603 14 годин тому

    My mini system jvc is out of frequency radio fm . Jvc mx-g7. What happens??

  • @guytech7310
    @guytech7310 16 годин тому

    I would have liked to see the design of those two sample filters you created. Design, construction, and testing. That would make a interesting video. For instance how did you spec out the size, positioning of the internal components & how to make any adjustments (presuming its possible with the construction method used.

  • @deang5622
    @deang5622 16 годин тому

    "I signed up to a degree in electronic engineering, NOT plumbing!"

  • @andrewmcfarland57
    @andrewmcfarland57 20 годин тому

    Can we see one of those nifty copper boxes on a VNA? 🙂

    • @FesZElectronics
      @FesZElectronics 19 годин тому

      Of course! I test all the filters I've built in the next episode.

  • @ThermalWorld_
    @ThermalWorld_ 20 годин тому

    Thanks for explaining Cavity filters.. Very black magic 😛

  • @andrewmcfarland57
    @andrewmcfarland57 20 годин тому

    Analog is king. 🙂

  • @StreakyP
    @StreakyP 21 годину тому

    great video many thanks... talking about amateur radio "abuse" of these things I have heard of aluminium beer kegs successfully being used as the conductive "cavity" for a VHF filter but the best one was a April fools joke about a 30' shipping container for a 7MHz (40 metre) cavity filter.

    • @Dazzwidd
      @Dazzwidd 2 години тому

      I bet a shipping container wouldn't be big enough for 7mhz. 14mhz though 🤔

  • @dalesmith8666
    @dalesmith8666 22 години тому

    Do a search for the "Kellermann Balun". It might be of interest to you and others, possibly try to simulate it and figure out how it works, the theory behind it. I contacted a few people on the subject, not much was given out. I'm a retired RF engineer, and also a Radio Amateur for 50 years. If I get the time I will also build one to test. Mind you that it is a 1:1 Balun. From what I can understand, it will handle plenty of power, depending on the size of the coax used, eg: rg142 or rg393. Should be a perfect Balun for a Balanced Tuner, on the input side of course, 50 ohms unbalanced in , output balanced.

  • @inrit
    @inrit 23 години тому

    I have been waiting for a clear and concise video on cavity filters forever! Thank you so much!!!

  • @trcwm
    @trcwm День тому

    Can’t wait for the practical measurements! 👍

  • @joansola02
    @joansola02 День тому

    Super interesting as always. Question: the 50 ohm source impedance in the models should be in series no? Or what is the effect of having this resistor in parallel with the voltage source?

    • @FesZElectronics
      @FesZElectronics День тому

      When modeling a voltage source, this is comprised of an ideal voltage source with a series resistor; when modeling a current source, its comprised of a ideal current source with a parallel resistor. If you add the resistor in parallel with an ideal voltage source it will have no effect (same for a resistor in series with the current source); from the "outside", an ideal voltage source, or an ideal voltage source with a parallel resistor behave in exactly the same way.

    • @joansola02
      @joansola02 22 години тому

      @@FesZElectronics Yes, yes! But at 5:30 you are using voltage sources. Therefore my comment . Thanks for this quick answer, and for your excellent videos!

    • @FesZElectronics
      @FesZElectronics 21 годину тому

      With voltage sources, if you right click on them directly, or going to "advanced", you have the option of defining the parasitics - series resistance and parallel capacitance; in the simulation, you can see under the "AC 1" parameter definition, the text "Rser=50" which is part of the voltage source definition -so the 50ohm series resistance is included into the voltage source, it does not have to be a dedicated external resistance.

    • @joansola02
      @joansola02 17 годин тому

      @@FesZElectronics Oh I see. So the external resistor is just an adapted load resistor? this makes sense.

  • @R2AUK
    @R2AUK День тому

    Great topic 👍

  • @csoszadavid4803
    @csoszadavid4803 День тому

    How can you choose the right Beta, If there is no problem everybody would choose 800, What is the method to choose "Beta"

    • @FesZElectronics
      @FesZElectronics День тому

      The component datasheet will usually give an interval; also the beta is current, temperature and Vce dependent; usually, to be safe, you should determine the realistic extreme values of beta (both maximum and minimum), and make sure the circuit works for both.

  • @BartKus
    @BartKus День тому

    Any chance for FEM of these filters? Like, what's an optimal coupling loop shape / position? Some coupling loops use flat wire instead of round. Why?

  • @electronics.unmessed
    @electronics.unmessed День тому

    Good explanation! Thanks for sharing! 👍

  • @TorSilviu
    @TorSilviu День тому

    What is the use of these narrow band filters? For an application such as a radio station you need a 100khz bandwidth, which this narrow band filter doesn't seem to cover, maybe it covers a 10th of that at best. Sorry I think I know why, it's so that small band signals don't mess with the modulation of bigger band signals

    • @gammaleader96
      @gammaleader96 День тому

      There are quite a few signals with a bandwith <= 10kHz. A narrow band FM signal for example uses 10kHz of bandwith and a SSB voice signal uses only 2.4kHz. Also for stuff like spectrum analyzers you need very narrow band filters to get a good resolution bandwith.

  • @jonathanlister5644
    @jonathanlister5644 День тому

    Excellent and elegant as always. This exemplifies the artiness of electronics!

  • @TheDiveO
    @TheDiveO День тому

    having seen this some time ago in one or some of Curious Marc's vids, this is finally building the missing link to this dark art of trolling the rest of electronics!

  • @w04h
    @w04h День тому

    The dark magic of electronics

    • @icebluscorpion
      @icebluscorpion День тому

      Rather the CURSED! area of the Dark Magic Electronics XD

  • @bobi_lopataru
    @bobi_lopataru 2 дні тому

    What?! How come I find out you're Romanian only now? You should have seen the look of shock on my face when you pulled out that electronics book... Te salut!

  • @anoimo9013
    @anoimo9013 2 дні тому

    6:40 Not quite sure why does coupling the two inductors give better attenuation for common mode.

    • @FesZElectronics
      @FesZElectronics День тому

      The coupling is usefull to cancel the differential inductance; in general, the differential current is very large compared to the common mode one, so any inductance that interacts with the differential current needs to be able to not saturate - this limits the realistic values that can be achieved - usually 10-100uH; with a CMC, since it only interacts with the common mode current, which is very small, inductance values can go in the 100uH-22mH; such large values would not normally be feasible as uncoupled inductors which do not saturate.

  • @andreybrodianski5596
    @andreybrodianski5596 3 дні тому

    Hi. I had very accurate working model of vacuum tube 12AX7. After refreshing my PC new installation (with new blue buttons tool bar) doesn’t run old saved files with tubes. Do you know what is the issue?

    • @FesZElectronics
      @FesZElectronics День тому

      You can check if the model is corectly linked to the simulation - there should be an ".include" or ".model" statement with a link somewhere in the simulation - maybe the link changed; if its something else, you could post the exact error that you are getting.

  • @geertas
    @geertas 3 дні тому

    in many class C amplifier the Capacitor which is parallel with the coil on the collector is omitted. Can you explain why that is?

  • @jacobfaseler5311
    @jacobfaseler5311 4 дні тому

    I went ahead and implemented these two features as components (source-like constraints) that can be placed in LTspice. The "Iconst" current constraint can be placed in series with a source, whereas the "Vconst" voltage constraint can be placed in parallel with a source. Example test-jigs included in the zip Link to the library: drive.google.com/file/d/1I3VxgBCDz8ntf56d5Q9Zr3E13vShVpg9/view?usp=sharing

  • @quinsattorney
    @quinsattorney 4 дні тому

    Thank you sir. Great simple demonstration.

  • @Freedom4Ever420
    @Freedom4Ever420 6 днів тому

    You have the best crystal method.

  • @harrimansat
    @harrimansat 6 днів тому

    one of the bests electronics channel! thanks!

  • @komoezaw4952
    @komoezaw4952 6 днів тому

    What is simulation software used for circuit design?

  • @alexengineering3754
    @alexengineering3754 7 днів тому

    Interesting videos thank you. Everyone love Software defined radio's

  • @ats89117
    @ats89117 7 днів тому

    The crystal model used is called the Butterworth Van Dyke (BVD) model. The model can be extended by adding multiple RLC circuits along with a single parallel capacitor to model the primary and secondary resonant and anti-resonant frequencies. For sonar usage, widening the band between the resonant and anti-resonant frequencies by addition of series and parallel inductance is an underutilized method for achieving better performance...

  • @MegaCadr
    @MegaCadr 8 днів тому

    I don’t know what other channel that I watch every new video start to finish as soon as it drops. Another fantastic video! I was part way through building a superhet transceiver by building each module, and the crystal filter was the most fun to build.

  • @Dazzwidd
    @Dazzwidd 8 днів тому

    Feszzzzzzzzzz.....

  • @themechanicly83
    @themechanicly83 8 днів тому

    Hi there for the demonstration of the filters with the sdr software with rtlsdr hardware there are horizontal lines in the waterfall which oszilate a bit over time. If i am not mistaking i would think this could be the automatic gain control adjusting amplification making the comparism wrong. What do you think?

    • @themechanicly83
      @themechanicly83 7 днів тому

      I just saw the agc s are disabled. Why do you think this happens?

    • @FesZElectronics
      @FesZElectronics 7 днів тому

      I guess that there are some very strong signal appearing that are overdriving the pre-amplifier, or just the input stage, and then it behaves as if the AGC is still on; or maybe its just a protection mechanism that cannot be turned off. I'm not sure what happened.

  • @RasoulMojtahedzadeh
    @RasoulMojtahedzadeh 8 днів тому

    You forgot about Monolithic Crystal Filters (MCF) :-)

  • @ashispradhan4237
    @ashispradhan4237 8 днів тому

    Is order of the filter the only reason why there were some extra spikes in the filter response ? Or is it also because of the imperfections in the crystal ? Also how can we get rid of those spikey responses ? Excellent video though.

    • @FesZElectronics
      @FesZElectronics 8 днів тому

      The spikes are caused by the imperfections in the crystals, but my assumption is that a higher order filter would filter these spike out since each crystal has its imperfections different from other crystals.

  • @lotecque
    @lotecque 8 днів тому

    Why did the first filter not make much of a difference in the SDR graph? Based on the plot of the filter characteristics I expected a much better result.

    • @FesZElectronics
      @FesZElectronics 8 днів тому

      I think the reason is that most major noise sources (like FM ~100MHz and GSM ~800MHz) are too far away to affect the operation of the SDR; I've seen a far more clear difference and improvement when building filters for the 2m band (~145MHz) since that is very close to the FM band and the Air Band - and filtering these out creates a major improvement.

  • @alejandroperez5368
    @alejandroperez5368 8 днів тому

    Consider changing your greetings at the beginning.

    • @FesZElectronics
      @FesZElectronics 8 днів тому

      What would you suggest as better option?

    • @tcarney57
      @tcarney57 7 днів тому

      @@FesZElectronics He wants one he likes. That he didn't offer any specific suggestions at all means he gave it no thought and doesn't really care in the first place. BTW, there's nothing wrong with your greetings. Ignore this guy.

  • @chengL10
    @chengL10 8 днів тому

    Thank you for the video, it was really helpful. Can I know the data sheet of the second filter of 10.7MHz ?

    • @FesZElectronics
      @FesZElectronics 8 днів тому

      Do you mean the 10.7MHz ceramic resonator? I used the same resonator in both measurements (with and without the 220R resistors); unfortunately I do not have a datasheet or order code for this component since it was just a random component I found in a box

    • @chengL10
      @chengL10 7 днів тому

      @@FesZElectronicsthank you anyways :)

  • @allkias
    @allkias 8 днів тому

    Thanks a lot. Would be very appreciated analyzing also N-path filters which are also characterized by very narrow-band frequency response.

  • @johnwest7993
    @johnwest7993 8 днів тому

    Thank you.

  • @m1geo
    @m1geo 9 днів тому

    I really like the AADE Designer tool. I have one of his AADE LCR meter. Great demonstration! 👌

    • @johnwest7993
      @johnwest7993 8 днів тому

      Me too. Mine was one of my most useful tools, although I've pretty much switched to using a NanoVNA because of all of the info provided across a wide frequency range in just a few seconds.

  • @davidjmstewart
    @davidjmstewart 12 днів тому

    At 4:48 you introduced a diode across SW2 to ensure current is always flowing through the inductor. How does the diode achieve this? Its anode is at ground so the only way for it to conduct is if Vs2 < -0.6V rigbt? Why is that node swinging below ground when it wasn't before (the only change is that you introduced the delay). Is it that with the delay, the left hand side of the inductor would be floating for a short period of time, changing its voltage to try and keep current flowing, and the diode now allows current to flow from ground, and into the inductor?

    • @FesZElectronics
      @FesZElectronics 10 днів тому

      The inductor current in a buck converter will always flow from the switching node towards the output; when the high side switch is on, the inductor behaves like a load, getting charged with current, so the left side is at a higher voltage potential than the right side; when the high side switch is off, current still flows either trough the diode or the low side switch, an this time the inductor behaves like a battery - it is producing a voltage which is inverted to when it was behaving like a load - so the left side is at a lower voltage potential than the right; if the low side is an ideal switch, then that side of the inductor is at 0V; if its a real switch (with non-zero voltage drop) or a diode, the switching node goes negative - this is how the diode is being polarized.

  • @nityanandadas5575
    @nityanandadas5575 13 днів тому

    Excellent video. Still one querry, in Frequency modulation , class C amplifier is used . Whether full sinusoildal Wave is the output of Class C amplifier or a limited angle ( less < 2 pi ) is used ? Thanks

  • @louco2
    @louco2 14 днів тому

    Amazing as always! Thank you

  • @BusDriverRFI
    @BusDriverRFI 15 днів тому

    In your first computer simulation, you have a 50 ohm source feeding a 100 ohm resistor in series with a 100 ohm resistor in parallel with a 1 ohm/1uF to ground. Where did you come up with this model for the simulation? Where's the necessary inductance? Is it already cancelled out? How do you reconcile this model with the antenna circuit definition of R+jX? How do you unbalance a resistor in series with an inductor and capacitor? You are familiar with R+jX, right?

  • @user-tr1yx3ol8m
    @user-tr1yx3ol8m 17 днів тому

    Very good!

  • @hoivien3001
    @hoivien3001 17 днів тому

    thank you

  • @hoivien3001
    @hoivien3001 17 днів тому

    thank you