When should I buy a GHz range oscilloscope ?  - Page 1
Forum section: electronics / testgear

author: electronic_guy
author_rank: Regular Contributor
timestamp: March 13, 2022, 06:20:17 am
content: Hi,I have seen most of the oscilloscope are around 100MHz or 200MHz or sometimes 350. I understand that one should buy things when there is a need. In RF the interest is mostly on frequency and power domain. Its understandable that the mostly used tools are SA, VNA and power meter in this domain. But I have seen there are GHz range oscilloscopes. I'm curious to know when is it those equipment are needed. My main focus is with RF. Still a beginner and I only have a CMU200 and HP power meter. I'm beginning to think if its better to buy a GHz range oscilloscope at some point. I'm sorry if this question is too obvious to explain, but I don't know the exact use cases of GHz range oscilloscopes and would be interesting to hear them from more experienced users of such capable instruments.Thanks.

author: jonpaul
author_rank: Super Contributor
timestamp: March 13, 2022, 06:28:40 am
content: We can discuss if you précis your RF field of interestHam radio?telecommunications /'mobilenetwork analysisSpectrum Analyzer repairBands UHF, VHF, microwave, mmwave?Seeking old analog scopes or modern digital?just having a 1 ghz BW scope still you must consider probes Zo (50,75 ohms or higher Zo ?Lot's to decideBon courageJon

author: electronic_guy
author_rank: Regular Contributor
timestamp: March 13, 2022, 07:21:51 am
content: Hi @jonpaulMy focus is on telecommunication side. Mobile communications. Since I'm a beginner to the practical side of things I have lot more to learn on actually building RF systems. After the undergrads I have rusty knowledge on electromagnetics and TL theory. I have experience in 4G and 5G telecom systems, but not on circuit level. Given 4G works mostly under 6 GHz and 5G goes up 24 to 54 GHz or 300GHz (i haven't seen the use cases of this much higher), I can expect to work on these frequencies. So both microwave and milimeterwave. But given the equipment price goes high with frequency, it would be enough if I can learn the stuff in microwave domain.I'm seeking for used equipment. Those equipment are costly enough on used market, I wouldn't go to new anytime soon. My current equipment are on 50 Ohm so I'd like to keep that standard.Thanks.

author: PartialDischarge
author_rank: Super Contributor
timestamp: March 13, 2022, 08:21:20 am
content: If your focus is general "RF" than a SA or VNA is more interesting. A scope is needed mainly for pulse responses, eye diagrams... There is no interest in watching a sine at 550MHz in a scope.

author: tautech
author_rank: Super Contributor
timestamp: March 13, 2022, 08:23:02 am
content: Quote from: PartialDischarge on March 13, 2022, 08:21:20 amThe OP already has a CMU200, maybe you missed that ?

author: EEVblog
author_rank: Unknown
timestamp: March 13, 2022, 09:17:47 am
content: Quote from: electronic_guy on March 13, 2022, 06:20:17 amOften it's not for RF signals as such, it's for signal integrity (remember fourier) measurements, fast timing measurements etc.To get anything useful from a >500MHz scope, you really start to need expensive active probes, or DIY high bandwidth resistor probes. The highest bandwidth passive probes stop at 1GHz (I think Tek are the only makers of those?). Everyone else is 50MHz.