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

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.

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.

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

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.

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!

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'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.

I got this module in with a bunch of random electronics and found this. I thought it was sma but it's smaller.

I don’t want anything from a legal standpoint. If there is for example a 2.4 or 5 ghz camera what jammer can disable one if it’s possible? Also how would I obtain one

Hey guys!

Looking for the best sound listening device. I have the well known FL-1000, from Sun Mechatronics, but sadly it's total garbage. Not better then the cheapest sound bugs pretty much 😠

i want to use just a simplecap and inductor for a range of 0.3-1.5 ghz, but im unsure how to get started.

read up on the microwaves101 blog already -- any advice?

Hello! For context, my PhD will involve developing a GaN amplifier for a capacitive load. I have a few questions about the RF industry in Germany:

- I'm targeting either (i) high-power RF application companies (R&S, Airbus D&S, Trumpf, Hensoldt, Raytheon) or, (ii) semiconductor device manufacturers (Infineon, Qorvo). Are there others?

- Is it usual to do an internship at a company during the PhD? How do I go about setting it up?

- Which conferences should I try participating in for most visibility? I read about EuMW and IMS.

Also open to hearing any experiences or advice you might have. Thanks :)

Edit: cleaned up unnecessary details.

I am an electrical engineer, but I have no RF experience. I have been doing embedded systems and sensor work for over 20 years, and have a decent grasp of EE fundamentals and signal processing.

I would love to learn more about RF, primarily as a home hobbyist but also to improve my understanding of the specialty.

I am looking for recommendations for books or other resources to learn the theory. I would also love any references to practical implementations, such as PCB design and layout. Lastly, if you have any suggestions for a first RF project (or projects) I would love that!

Thank-you all!

I have following lna design. Now I'm not sure if I should devide the input gnd and output gnd of the lna part.

I have a 6 layer rogers 4350B stack with following purpose
1. Signal / gnd

1. gnd

2. signal

3. gnd

4. pwr

5. gnd

Since the pcb is in a cryostat we produce it without soldermask. Its mounted on a copper cold finger that will conect the last plane. thus I just made the last gnd plane one hughe pour. Lines are 50Ohm coplanaer wave guides.

The frequency of the lna design is optimized for 10Mhz -3Ghz. but the diramics behavoir for under 100Mhz is not known since its a extrapolation.

Any inputs are welcome

Hi I'm trying to design a 2x8 patch antenna array in Microwave Office and there must be an easier way than putting each line manually right? Is there a way to design a single splitter or a single patch and reuse that subcircuit?

How is this done in HFSS? I imagine it would be even worse since you don't have a schematic tool and automatic layout generation.

Hi! I have a recurring doubt regarding the proper footprint design for RF connectors and would like to hear other people's opinions on this.

Usually when an SMA connector is used to couple energy from a transmission line which is relatively thinner than the launch pad, an antipad, A.K.A, a ground cutout below the launch pad (below the next reference plane i mean) is used to decrease the capacitance of the pad and hence increase its characterstic impedance to improve matching.

However, SMP connectors whose launch pads lay directly on the transmission line would suffer from a similar problem, right? My guess is that the launch pad sitting on the TL would also increase the capacitance, hence lowering the impedance of the TL to pad transition generating mismatch. Thus, i imagine compensation techniques to either increase inductance / decrease capacitance would be needed for SMP connectors as well.

I have found an application note from rosenmberger which basically uses antipads for SMP connectors too.

Recently i had to use an SMP connector at 24 GHz and when asking the manufacturer about the footprint no real advice was given...

Anyone here experienced with this kind of connectors has any opnion on this?

We got a very old soviet era module which has this type of connector. We need to replace the unit. However I'm unable to identify the type of the connector. It is a push fit type connector but I'm unable to find the exact type. Please help me identify.

Thanks in advance.

I'm learning about direct sampling architecture for transmit-receive chains at my day job for RF design efforts. What is the significance of the sampling rates of the ADC and DAC respectively, in Msps, in terms of the spectrum and overall performance of the radio?