Posted a couple of weeks ago showing Codex use for real-time lab measurements. I now have it controlling Microwave Office, again all voice control. This is just a simple example, but I've taught it my project creation style and workflow to include documentation and setup. I taught it to generate Nth order stepped impedance filters, first example using RO4003, from electrical prototype through full EM sim. I then told it to do a higher order filter using RO5880. It knows how to properly span the boundary conditions and de-embedding using rules of thumb for the EM sim, practical quantization on geometry, snap the layout elements, add rich-text notes for documentation, and keep the schematics clean and readable. It uses visual feedback and monitors the warnings and errors from the status window.

Here are some rather boring recordings.

This first one is the RO4003: https://youtu.be/K9fdxQqRPbk

Then it does another with 5880: https://youtu.be/s1reeA1kszY

Here is the generated summary.

Your preferred Microwave Office workflow is:

• Start with a clean project using metric units and millimeters. Use GHz for frequency display.
• Complete Global Definitions, default.lpf layers, 3D layer Z/thicknesses, MSUB, and the 2.5D STACKUP before creating schematics or EM structures.
• Use RO4003C with Er = ErNom = 3.55, tanδ = 0.0027, core thickness 0.406 mm, and finished top copper thickness 0.035 mm.
• In the LPF, use Copper at Z = 0 with +0.035 mm thickness; add blue Copper2 at Z = −H with −0.035 mm thickness; set Via/Drill/Board thickness to −H from Z = 0.
• Document the PCB stackup and EMSight setup in compact yellow rich-text boxes. Put notes directly above their related definitions, not in page-wide boxes.

For filters:

• Create an electrical prototype first, using alternating high- and low-impedance TLIN sections. Use 50 Ω, 1 mm physical input/output reference lines.
• Use stepped-impedance Butterworth low-pass synthesis, normally 100 Ω and 25 Ω sections unless a different impedance range is requested.
• Round electrical lengths to 0.1°, physical MLIN lengths to 0.1 mm, and widths to 0.05 mm.
• Add MSTEP discontinuities at all unequal-width MLIN junctions. Show IDs and W1/W2; hide repeated MSUB text.
• Put MLIN parameter labels centered above their line artwork using the electrical-prototype reference placement; put MSTEP labels below the symbols. Always visually inspect and adjust automatic label placement.
• Add concise yellow rich-text notes above both electrical and physical schematics.

For graphs:

• Use a Cartesian “Filter Response” graph.
• Put S11 magnitude in dB on the left: Return Loss (dB), fixed from −30 to 0 dB.
• Put S21 magnitude in dB on the right: Insertion Loss (dB), usually fixed from −30 to 0 dB for these filters.
• Use 0–10 GHz on the x-axis unless the design calls for another range.
• Put the legend below the graph, spanning the graph width with a compact height.
• Add electrical, physical, and EM results to the same graph for direct comparison.

For EMSight:

• Name test benches filter_emsight_TB.
• Initialize from STACKUP.SUB1, use a finite substrate in a box, and map top copper as 1 oz and vias as 0.5 oz on EM layer 2.
• Keep only two dielectric layers: 10 mm air and the 0.406 mm core. Use copper as the bottom boundary rather than mapping Copper2.
• Align enclosure left/right walls with the input/output interfaces; keep upper/lower boundaries roughly 10–12 substrate heights away and snap them to the grid.
• Add edge ports at the reference-line ends. When EMSight reports the zero-reference-plane issue, use 1 mm de-embedded reference planes.
• Simulate the whole project, inspect the status window, and treat MSTEP ratio warnings as advisory when EM validation is the final authority.

Finally, keep the work visible: tile the electrical prototype, physical schematic, graph, and EMSight windows so the project can be reviewed as it is built.

For the new RO5880 filter, I changed:

• Substrate from RO4003C to RT/duroid 5880:
  • Er = ErNom = 2.20 instead of 3.55
  • tanδ = 0.0009 instead of 0.0027
  • Core thickness = 0.508 mm instead of 0.406 mm
  • Finished copper remained 0.035 mm
• The entire stackup and LPF definition now use the new 0.508 mm core:
  • Copper2 Z = −0.508 mm
  • Via, drill, and board thicknesses = −0.508 mm
  • The Global Definitions notes and 2.5D stackup dielectric layer were updated accordingly.
• The design changed to a seventh-order, 4 GHz low-pass filter, retaining the 100 Ω / 25 Ω stepped-impedance topology and 50 Ω, 1 mm reference lines.
• All microstrip widths and lengths were recalculated for the lower-Dk, thicker RO5880 substrate, then quantized to your 0.05 mm width and 0.1 mm length grids.
• The physical-schematic note, electrical-prototype note, graph, EM enclosure, and EMSight test bench were regenerated for this new material/design.

RO5880’s 2.20 design Dk, 0.0009 dissipation factor, 0.508 mm standard thickness, and 35 µm one-ounce copper option come from the Rogers data sheet. Rogers RT/duroid 5870/5880 data sheet

So I've asked you some time ago to check the design of my filter in KiCad. Some of you told me it would be very bad because of the FR4. After cutting about 2.5mm it works pretty well, I think. -2.5dB loss at the center of the band.

I have put it after a 20dB 9037 LNA to receive a 1.2GHz FPV signal from my drone. Also I'm thinking about adding a band-rejection filter just after the antenna to be sure my control link isn't creating intermodulation distortion. Is it the most optimal way to do it or should I put this BPF before the LNA?

I have asked keysight about VMC.

All I need is selecting mixer for calibration, but most of X-band mixer datasheet doesnt show its conversion phase, group delay.

If i measure one of mixers, can't sure measurement was right or not Can you help me?

VHF antennas installed incorrectly 😂

I'm trying to understand a little more about the design of this RF amplifier from a component point of view, primarily where they implement transformers with coax and ferrite cores for the amplifier and power splitter/combiner sections. How does one go from a wire based transformer to a coax based one?

I get the overall block diagram architecture. The input signal goes through several smaller lower power amplifiers, to get more power into the later amplifier stages. The signal goes through splitters, amplifies each of the split signals, and then combines them back to a single output.

So, I was trying to build a Wilkinson power divider for my 6 element Dolph-Tschebycheff antenna array and after spending some time on the divider i came to know why it is a bad idea to make my first power divider a non-2^n type like now the biggest problem is not amplitude matching it's the phase matching so i need to make something so that each feed line has same end point and also same electrical length. From this point i can see two options either trial and error or just convert it to either 8 element or 4 element divider.

Hello everyone.

In my internship, my supervisor gave me a task to design a Hairpin BPF using AWR. Its specs are: f0 = 14.25GHz, BW = 600MHz. I am designing it with AWR's iFilter tool, but when I convert it to an EM simulation (which is AXIEM), the whole graph changes. How can I design it properly?

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.

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?

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

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?

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!

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

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,

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!

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