This channel is focused on Electronics Engineering videos, covering aspects from different areas. Learn about analog design, RF, instrumentation and general electronics technical design.
I worked on this extensively about 20 to 25 years ago, when technology was emerging to make this practical with off the shelf DSPs, without having to rely on dedicated ASICs or a large component count solution. There were other complexities in my application, as it was for space, and I was also using additional methods applied to the PA itself, based on Doherty techniques, to improve efficiency to reduce power budget and improve thermals. I never thought I'd ever see a RU-vid video on it though! Bravo!
Great video, I got a bunch of RF transistors and I wanted to test their liability, so I'm going to make a GHz VCO for the matter. Said to myself, I look for some suggestions and I came to your video!
Thank you for the video, it is darn near exactly what I was looking for. If I were to suggest adding things, it would be to give the part number of the transistor you are using, and to show how you got the base impedance. I looked at the datasheet for the transistor I want to use and low and behold it has a piece of a smith chart showing the resistive and reactive components at a few different frequencies. There seems to be a trend so I think it is safe to interpolate a bit at least between the marked points. Thank you again for the video.
Any application where you are measuring very weak signals in conjunction with large signals... how can you visualize a signal that is 0.000001 with other that is 100? Log scales!
Hi, sorry but I still do not have clear idea what noise temperature is. So is it defined for amplifier or antenna out of blue or it depends on physical temperature? How to measure it?
I'm a bit confused here: for the antenna temperature do you mean the temperature that the antenna is itself; - or do you mean the temperature of where it's pointing i.e. the sky or the horizon...at 24:25 you say it's the temp of the antenna itself, then at 25:12 you say looking at sky it's different...?
There needs to be a coil calculator which puts out parameter spectrums/ranges (of interdependent/covariant variables) depending on how many variables you determine/collapse. Coils can look very differently yet show the same frequency. I would've liked to set the frequency and then narrow down on other parameters by setting materially determined (available) parameters like wire radius, top load dimensions to then move on to "turn number", coil circumference. but there's no such calculator available and I'm too slow of a learner to produce it
Nunca havia visto o casamento de impedâncias explicado como esse ajuste de tensão-corrente, muito bom. É tão difícil achar boas referências em RF, parabéns pelo canal meu caro, mina de ouro em conhecimento. Sucesso!
Very nice way to make us understand...you make a lot of efforts to create such nice vedios. I also listen old school people..they talk a bit slow..that makes us understand better...i wish you also try talking a bit slow...
I also experiment with VCOs I am a hobbyist and I once tried one of these cascode oscillators for VHF and UHF. I used the 2SC3355 but the 2SC2570 is even better in some instances. It's beta is higher than the BF199. In another video ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-i_CPkmV_ZbQ.html I saw a luxurious bench and instruments, It would be great if you showed us the results of this circuit and some test points with the oscilloscope and the spectrum analyser. People love reality behind theory and chalkboard, so please set the bench and hock up probes and rock n roll.
great video, the best I have seen so far explaining the phase detector and bit recovery clock. You could implement the pulse edge detector in software by attaching two interrupts (a rising edge and a falling edge interrupt routine) performing the phase sensing.
Great video! Unfortunately for me, I'm still missing the point at which the spreading sequence applies. Will it matter if we apply the spreading sequence to the data stream - as what was shown on a slide at 6:26 - first and then mix it with the carrier or we should first get the modulated data stream signal and then apply the spreading sequence? As I see it it should produce the same result, shouldn't it?
Do you have the capacitance values you used for this circuit, trying to recreate these results in the lab. I tried with 5pf caps and a bc560 transistor and could not reproduce.
Hello! I had been trying made audio phase shifter using STM32F303 microcontroller using a copmlex FFT. BUT A processor was busy 80% of time.As a result - main logic of a program and modulation process had not been realized.Your design uses Waver principle - as I understand.
How to work with such a high frequencies? 1 pF capacitor has impedance 15 Ohm, 2.5nH inductor (1mm length of 1mm diameter wire) has impedance 18 Ohm... Any millimeter of wire can leads to parasitic oscillation in an amplifier.... I made only FM transmitter 100MHz, and 5mm of wire increase SWR. But what we will have in 10GHz? Any micrometer influences on SWR in a cable?
