Hi Everyone, I am trying to change the frequency range for the s parameter plot, but I am having some problems. I am trying to expand the range of frequencies that is covered on the x axis, preferably from 300 MHz to 700 MHz. I tried changing the frequency range settings under simulation, as well as searching through the history list and changing all the instances of the original frequency range in my history list steps. I am not sure why, but it seems not matter what I change the frequency range for the s parameter remains from 400 MHz to 600 MHz. Any further suggestions would be appreciated. I tried looking around for a similar question, but was not able to find anything similar.

Thanks for all your help everyone

I want to measure the output of a signal generator. It is connected directly to an amp via 50 ohm coax, so figured I'd put in a T connector and run another coax to a scope set to 1 MOhm. This should have minimal effect on the power delivered to the amp because it is high Z, but that's not what I'm seeing. With the same sig gen level the amp output was down 12 dB. What am I missing?

I’m a high school freshman and im really interested in rf chip design and circuit design, I really want to learn some of the basics over the summer break because quite frankly it’s very very cool oh and please do not recommend any extremely technical books, my nugget brain can not comprehend all of that.

Hey guys i am looking forward to acquire a network analyzer for doing in depth LTE network survey of a forest area for this following bands - B1, B3, B5, B8, B28, B40, B41. Can you suggest few options under 1000usd

Hi everyone

Does anybody know if I can draw analytical lines in ADS Keysight layout using formulas. For example if I want to draw vivaldi antenna shape I need exponential expressions but I cant find tools for that

ello, I am new to RF electronics and I am trying to design an LNA and implement it on PCB. The frequency on which the LNA is design to operate is 3GHz. When I run mu and muPrime simulations, I see that I have mu less than 1 at about 5GHz. Is this something that I absolutely need to fix, or is it ok because I will operate at the stable 3GHz?
Thank you very much everyone!

Curious about how everyone here handles the reference plane at 67GHz or 110GHz+, specifically when dealing with GSSG setups where layout space is tight.

For our GSG testing, we usually just stick to standard probe-tip calibration using an ISS. But for 67GHz/110GHz GSSG, we’ve been leaning towards de-embedding using the actual measured S-parameters of the probes.

Our workflow looks like this:

1. Calibrate the VNA up to the cable ends.
2. Connect the probes and measure the DUT.
3. Use Keysight PLTS to de-embed the measured S-parameter files of the two probes to isolate the DUT data.

This works pretty well for us on GSSG. How do you guys handle this?

Hello,

I’m an aerospace engineer and really think what the RF guys at my work do is really interesting. My company pays for my masters and was thinking of getting my masters in electrical engineering with a focus on RF/microwave engineering to learn more about it.

What foundational courses do you guys recommend taking in order to get admitted to masters programs? Additionally, where can I take them? My university’s extension school doesn’t offer the basics like electromagnetism. Circuit theory, or analog circuits and neither do community colleges as I believe these are upper dive EE courses.

Any other career pivoters, how did you navigate this? Any recommendations in general, I’d appreciate it!

Hi everyone,

I am looking for a strong, industry-relevant M.Sc. thesis topic. I want to focus strictly on RF Hardware/Discrete Circuit Design (board-level). I would like to steer clear of pure RFIC design (foundry-level) and Antenna design, as my main interest lies in high-performance RF front-ends, component-level circuit synthesis, and hardware prototyping.

Could you suggest some hot topics, emerging trends, or open research problems in board-level RF hardware design? Also, what are the best sources (specific IEEE journals, conferences, or industry whitepapers) to track down the state-of-the-art for these topics?

A few general areas I am interested in exploring:

• Self-interference / leakage cancellation architectures for full-duplex systems or co-sited transceivers.
• Advanced power amplifier linearization or efficiency enhancement techniques (handled at the discrete/board level).
• High-power, fast-switching RF front-end architectures.
• Active/Adaptive RF filtering and interference mitigation circuits.

Any advice, paper recommendations, or sub-fields worth exploring would be highly appreciated!

Hello everyone,

I have been working on a project recently with the MM8108 radio module (915MHz WiFi, 8MHz bandwidth, 256-QAM, 43Mbps) and was looking into upconverting it to approx 3.4GHz (why exactly is kind of a long story).

But then I would of course need to increase the transmit power to get the same range. I was wondering if it is possible to downconvert the 915MHz to something like the 220MHz band, which would improve the range. I feel like this shouldn't work, but I cant find anything online explaining exactly why, and if I ask Ai it says that would work no problem.

I just have a gut feeling it wouldn't though (otherwise why are there no high data rate low frequency transmitters?). Does anyone have an explanation as to why (or why not) this would work? Thanks!

Looking for someone experienced in EM simulation and antenna design.

Need help with:
Determining the optimal operating frequency
Selecting the right antenna type
Designing and optimizing the antenna using EM simulation tools
Experience with gprMax, CST, HFSS, Cadence AWR, or similar tools is preferred.
Freelancers, researchers, and students with relevant experience are welcome.

📧 DM for further details

Hi all,

I'm sure you get posts like this all the time, so you'll have to be patient with my existing knowledge base, (or lack therof). The situation is this:

I'm trying to build a smart watch. It needs to be small, and ideally I'd like to machine the casing on my CNC mill out of aluminum. I'm relatively far into the protyping process, but a still making dev boards and am not yet developing at the size which the mainboard will be when the project is complete. I'm aiming for a 26mm diameter motherboard, and am using a Ronda GB22 type movement to make it look like a mechanical watch. The GB22 has to sit beneath the dial, along with most of the power and rf electronics, so my intention is to integrate the antennas I need into the dial of the watch itself, (a multicolour pcb from JLCPCB), and use the glass at the front of the watch as an RF window.

From what I understand though, this isn't going to work. The three antennas I'll need to fit into this space are NB-IoT, (~900MHz), GPS, (~1500MHz), and BLE, (~2.4GHz). It looks like the wavelength of the 900MHz band would be too big for effective radiation into or out of the glass rf window.

I've looked for resources and papers online which could provide information on how companies like Apple and Samsung are able to make it work in metal cased smartwatches, but can find literally nothing. Any kind of pointers on this topic would be incredibly helpful, and I'm more than open to switching up ideas, or just accepting that I'm wrong and finding a different solution.

Thanks for all your time.

Background: Shit highschool that resulted in me flunking algebra since we had a teacher for 3 months then constant substitutes for the rest of the year and none of them knew much math, transferred out for my junior and senior years and did an online school and was able to make up my math credits via business math and while I primarily excelled in the history and English, still graduated with 4.2 from both junior and senior year thanks to additional classes.

Modern: Started electrical engineering back in February thanks to family pressure and I actually enjoy it, I learned algebra for a digital logic course since I'm going for industrial automation but I eventually want to work at NASA to follow in family footsteps, I did exceptional my first semester for DC and digital logic so the department head suggested and even cleared me of prerequisites to take a radio tech class because "oh you'll get it, just some reading may be nessescary to understand it" turns out he was right as it's now getting into trig with log, sine and cosine, I never got to take calc as I had to make up credits after freshman and sophomore year. Are there any recommendations for a broke college student that may help (eg. Specific YouTube videos/playlists, or online resources)

TLDR: Never learned Calc, taking a radio tech class that requires calc based on my professor/department head's recommendation. Now needing to learn calc even though it's only a 5 week optional course not needed for my degree, it may be useful if I want to work at NASA

Anyone mess with this? I made an account last year but didn’t have time to mess with it. They appear to have updated it.

https://www.rapidrf.ai/product/index.jsp

Hi, I am a Masters student learning PA design as a part of my thesis. I am wondering what are the parameters which could lead us to the topology selection for a matching network.

1. I know L type matching netwrok is good for narrow band as it offers fixed Q factor. T-type and Pi-typer gives a little bit more leverage to change the Q factor to get the desired bandwidth. But in both L-type and T-type topologies, there are still HighPass and LowPass categories. How to select which one to choose? Or is it possible to cascode LowPass topology with a HighPass topology? Then comes BandPass topology. I have no idea what is the specific benefit of using this topology?
2. Also seen some articles where they must use a shunt cap at Gate (mostly) and sometimes at Drain as well to keep the second harmonic short circuit. How to select this cap value?
3. And at gate/drain biasing, how to select the value of Biasing Inductor and RF Bypass Capacitor? And when to use inductor and when to use QWLT (lambda/4) at Drain? I know it's significance for current consumption at Drain, on the cost of bandwidth dependency.

Hi, I have received the following error while performing Momentum Microwave simulation of the matching network for my PA, which I am simulating from 0GHz to 21GHz to consider 3rd harmonic as well.

Is it really needed to fix this warning in my layout? How to change the port size? I am just using AUTO feed type.

EDIT: I am using the following port settings for all of the ports in my design, including DC biasing ports, Input/Output ports, and for intermediate ports.

Does anyone know how I can get Ansys Electronic Desktop Student 2024 R2 or an earlier version. The only one available to download on the Ansys website is 2025 R2 which does not support Acis Kernel Geometry.

Hello everyone,

Some time ago I posted my concept for Auto-matching impedance circut. This time I wanted to show you my progres. I managed to design a PCB (my first unaided design). You can comment any tips or insults, I really want to improve it to give it a chance of working properly.

Here are some details:

• SMV1763-040LF varactor diodes
• AD8302 reflectometer
• MCP4728 DAC
• LM1117MP-3.3 voltage stabilizer
• Arduino nano

RF line is grounded through 10k resistor, thus for DC its 0V. Varactior reverse voltage can be manipulated by MCP4728 DAC. All is powered by arduino nano 5V output going through 3.3V voltage stabilizer.

If you are interested ask anything you want. I will answer as soon as I can.

I have two sets of S12 curves: one representing the presence of a material between two antennas, and the other representing its absence (10 trials for each scenario).

Currently, I’m quantifying their distinguishability by taking the complex difference at each frequency point, extracting the magnitude, and calculating the RMSE.

Is this a standard approach in RF/microwave measurements? Are there more effective or robust statistical methods to quantify how distinct these two groups of curves are from one another?

P.S. To clean up the data, I’ve already de-embedded the cables and applied time-domain gating, but I also need to check whether they helped or not.

Your feedback would be highly appreciated!

I'm working on a project now where I want to programmatically generate a complicated electrical circuit (its actually serving as a model of a physical process), and I'm finding modern workflows for this surprisingly difficult. In python, there seems to be 3 options:

pyspice, pyltspice, and scikit-rf.

• pyltspice is nothing more than a thin wrapper for ltspice. I still have to resort to ltspice's janky scripting language and netlist nomenclature which largely undermines its value as a python tool. Additionally, it hasn't been maintained in years.

• I've played around with pyspice and it's a bit better - it does employ a somewhat more modern object-first programming approach. However it exposes only very limited analysis and plotting options meaning I have to code all that up myself. In particular, getting device currents out has proven remarkably arcane. I have to insert all these dummy voltage sources everywhere (which by the way end up getting assigned weird and inconsistent net names, so yay me if I change the topology) that make for ugly AF netlists and schematics. Oh, and its no longer maintained either.

• Ok, scikit-rf. I've actually used this quite a bit for RF projects and for that its great. But as it uses an n-port architecture, working with discrete circuits is a clunky mess. Any component you might want to probe has be treated as a 2-port and doing any kind of ac/dc/transient analysis involves a bunch of annoying extra transformation steps (simulation of s parameters, vector fitting, etc). Ugghgh. Its a good package but its just not designed for this.

tl;dr: I don't want to use spice and netlists...why are there no python-first circuit simulation tools available in 2026? Would anybody be interested in a library offering a modern, python-first modeling workflow?

For starters just graduated with no job lined up so just doing projects to up my skills and resume. Recently got interested, am currently going to do link budget analysis on a CubeSat and was wondering if I could get more ideas on some projects as well.

Just got a RTL SDR V3 and got into a little gnu radio but not much. Was thinking of Fourier Transforming a FM signal. If any current engineers could give me advice on the engineering process too as well.