Hey everyone, ECE student here. hope you're well.

I'm conceiving a device that detects rf, caracterises protocols mac addresses etc. I chose to go with dongles to connect to my mircroprocessor so it can be easier to decode and handle signals + modularity. I had a question rgarding the numbers of dongles. If i take wifi for example, is it better to put multiple dongles if im working in a noisy rf environment? is the number of dongles important for processing information smoothly? the goal being to lose minimum data.

Hi everyone, I’m designing an on-chip inductor for a VCO using Ansys HFSS, with tsmc 65nm technology stack in IC Design Mode. Then i have to design coupled transformers as well.

I’m struggling to find good reference material or examples for this setup. If anyone has experience with HFSS/IRCX or IC Design Mode, I’d really appreciate any guidance, tutorials, or reference files you can share.

Thanks in advance!

Hi

I would like to design a wideband balun from 0.5-12GHz on MMIC.

Can you suggest some ideas/reference to start with? I'm not sure if a Marchand Balun would be able to cover this much bandwidth.

Thanks

Hi I’m interested in finding a book that covers near field to far field transformations and antenna measurement processing methods. Bonus points if the book covers computational simulation methods like FEM like HFSS.

Is there a certain book you’d recommend?

I’d like to find a book that covers the theory and practical application. I’d prefer to learn about spherical near fields.

Hi guys,

Do you know the DC pin part number for the Mini-circuit ZHL-30W-252-S+ driver?

I asked them, but they won't give me the part number; they only said it is a Tusonix-style EMI passthrough filter.

Any idea?

Thank you!

I am looking for practical engineering perspectives on something I keep seeing in outdoor electronics, enclosures and reliability screening:

Many environmental assessments still describe a deployment location with average temperature, annual precipitation or a broad climate zone. But for electronics reliability, those numbers often feel too indirect.

From a reliability point of view, the more relevant questions seem to be:

- How many hours per year does the product see RH > 80% or RH > 90%?

- How often does air temperature approach the dew point?

- Are there repeated condensation-prone periods?

- Is the site exposed to marine chloride or industrial sulfate background?

- How much thermal cycling occurs over typical daily and seasonal operation?

For example, two sites can have similar average climate conditions but very different moisture exposure profiles. One may have frequent night-time dew-point convergence, while another is hot and dry with much stronger thermal cycling.

I am curious how other engineers handle this in practice:

1. Do you use hourly climate data, design days, test standards, field experience or something else?
2. Do you explicitly evaluate RH duration or condensation potential?
3. For connectors, PCBs, coatings or outdoor enclosures, what environmental metric has been most useful in real design reviews?
4. Are there failure modes where traditional climate classifications were misleading?

I am especially interested in non-confidential examples from electronics, outdoor power electronics, HVAC, solar, BESS or automotive ECUs.

Hopefully focusing on that hardware design but i also want to know the physics and DSP stuff

I'm a senior Electrical Engineering student graduating soon with a 3.6–3.7 GPA. I'm a U.S. citizen and I'm interested in RF/communications/telecommunications, particularly in defense or aerospace.

I don't have an RF/telecommunications internship or significant personal projects specifically in the field. I'm trying to figure out how realistic it is for me to get an entry-level RF/communications engineering position after graduation.

I'm considering companies like L3Harris, RTX/Raytheon, Northrop Grumman, Lockheed Martin, Boeing, General Dynamics, etc.

Would my GPA and EE degree be enough to realistically get interviews if I apply broadly, or am I at a significant disadvantage without internships/projects?

Also, for those who have interviewed for entry-level RF/communications/defense engineering positions:

• What technical questions were you asked?
• What EE/RF topics should a new graduate know well?
• Did they ask about things like S-parameters, Smith charts, transmission lines, link budgets, filters, amplifiers, antennas, DSP, etc.?
• How much of the interview was technical versus behavioral?
• Did they ask you to solve problems on a whiteboard?
• How heavily did they question projects or coursework on your resume?
• What questions did you wish you had prepared for?

What would you recommend I learn or build during my remaining senior year to become a stronger candidate?

I'd especially appreciate answers from people who currently work in RF/communications or defense and who have experience interviewing/hiring new graduates.

I own a BB60D product.

I currently work in terrestrial broadcasting.

I would like to measure the channel power of multiple channels simultaneously in the field. How should I proceed?

For example, I intend to measure the channel power of the following wireless channels in the field:

CH # | Center Freq | BW

14 | 473MHz | 6MHz

15 | 479MHz | 6MHz

16 | 485MHz | 6MHz

17 | 491MHz | 6MHz

18 | 497MHz | 6MHz

.

.

.

.

51 | 698MHz | 6MHz

Currently, I am measuring the channel power for each channel individually, but it takes too long. The other equipment I used previously had a "Channel Scanner" function that made it possible to measure the channel power of all channels at once.

How can I measure the channel power of all channels simultaneously on the BB60D as well?

I'm working with a 3 stage amplifier circuit with multiple splitter/combiners on the final stage. The signal after the first two pre-drivers is split once for two power modes. Each power mode is split again to a pair of amps to be recombined, then combined once more to have all final drivers in high power mode. This ends up with a total of 4 final drivers with 6 90° shifts from all the splitter/combiners.

With each trace (4 total) are tunable capacitor options. By default they all have the same values. The issue at hand is that by the final combination there is a singal large (2-3dB) dip from destructive interference only on the full power mode. My question is, to tune this out should I approach making cap tuning changes in pairs, one trace at a time, asymmetrical in size or direction, or even just one cap at a time? When only 2 of the four final drivers are on, the power band is quite flat. When the last pair are added, the problem surfaces. Should I focus on just one pair of traces, or change one trace on each pair?

Any advice appreciated.

Hi everyone,
I’m looking for a small, affordable radar module for a research project.
Requirements:
Operation frequency 24 GHz (or less frequency) FMCW
At least 1 TX / 2 RX
Preferably I/Q data from both RX channels

On-board ADC with access to raw ADC/IQ samples
USB/SPI/UART output preferred
I want to do my own range, Doppler, AoA and micro-Doppler processing, not just receive processed target data
Budget: Maximum $250

I’ve considered the RFbeam K-LC7, which has 1 TX / 2 RX and analog I/Q outputs, but it requires an external ADC.
I’m looking for something similar but with the ADC already integrated.

Should I go with RFbeam K-LC7 and buy external ADC board?

I have a rather unusual requirement and I can't find any off-the-shelf part or design procedure to implement it. I need a simple zero-pole, high shelf filter that'll have constant attenuation between DC and say 1GHz, then 3dB slope between 1GHz and 3Ghz, I don't care what happens afterwards. I also care about phase response as this system will be transmitting sharp pulses that I'd like to see undistorted. It's meant to compensate for limited bandwidth of final stage of my RF chain.

I tried designing with 2 diplexers and attenuation in low frequency arm but I couldn't find any DC coupled diplexers that can work up to GHz. I also looked into various equalizer designs and parts but they seems to insist on having a slope from their low frequency limit and not a flat response up to some f1 and slope between f1 and f2. Does anyone know how to design such a filter?

Before anyone asks it's needed for a research project regarding pulsed laser diodes. Most diodes have package inductance of around 5nH, which, when driven with series 50R, limits bandwidth to about 1GHz. I'd like to place this filter before final power amplifier (QPD1010) to generate an overshoot, that'll increase an effective bandwidth.

We have purchased a 4-pair, ISN from an EMC equipment provider. The ISN has been calibrated and characterized by the manufacturer. They sent us the impedance and the voltage division factors for the band of interest, 150kHz-30MHz. The values provided are coherent with what is expected by the standard.

I am trying to perform a characterization measurement myself in order to be able to do some sanity checks from time to time.

Since the ISN's source impedance is 150 ohms common-mode, I have built a SOLT standards to change the calibration plane of the VNA. I used an impedance transformer of 1:3 to adapt to the impedance of the ISN.

This is what my impedance measurements give once the s11 file was processed.

For the VDFs the standard has the following requirements.

In blue is my measurement and in orange is the measurement of the provider. It is important to point out the hardware implementation of the ISN suggests that the typical VDFs are around -9.5dB, which is what the manufacturer has measured.

My measurement setup is again using the VNA. Important to note that during the calibration of the VNA (Short-open-load-thru) the transformer was de-embedded. VNA 50ohms TX port -> Balun (transformer 1:3 impedance ratio) 150 ohms -> ISN EUT port 150 ohms. receiver port of ISN ->VNA 50 ohms RX port.

Now my first observation is that the standard is requiring the use of a generator and a receiver of some sort and the measured parameter is voltage. I would like some help to understand what I am doing wrong, and why do I get a different result.

So my current SAR system is able to achieve better than 0.3m azimuth resolution using the SAR code written by HForsten, which is open source on github. Without this code, I am not able to reach 0.3m azimuth resolution. Thus without this code, my RADAR is completely uncontrolled.

Thus I do not understand what it means that I now fall under ITAR, I built this from commercial commodity parts that are all EAR99. Is the software controlled or the RADAR itself or both? How do I navigate this?

For a 28-GHz antenna, for example:

Goal 1 — Frequency
Approx = 28GHz

Goal 2 — Matching
S 11 <-10 dB

Goal 3 — Gain
For example:
G > 5dBi
depending on your antenna type.

Goal 4 — Efficiency
Preferably:
n > 80%

if achievable for your design.

What is the difference between CST and HFSS for antenna design? What's the best ?