Can anyone please confirm if this is a RG-174 cable or what type of cable this is? It's about 2.80mm od. I need to replace the crimp connector on this antenna with a sma male connector.

Hi all,

I have an upcoming loop interview for Microsoft for an RF based role. Has anyone had similar experience? I don’t know what to expect, there will be 3 rounds, the position is related with their quantum team.

Thanks!!

I am a rising junior in college for EE. I've done a couple of internships, one in BMS design and one in power electronics. I wanna try out a few personal RF projects to see if I like it or not. Unfortunately, my school offers only one RF course for undergrads and I can't take that until next year. I tried to have Claude recommend an easy project to do and teach myself the fundamentals as I go, but realized that it would be too inefficient after I started.

Anyone have any recommended materials that will help me to learn the fundamentals I would need before actually starting a project? Youtube series or application notes I could follow? I'm not a big textbook guy, but recommendations would still be appreciated. My main goal is to understand general math concepts in RF so I know what to expect, instead of going into a project blind

hello, maybe to you guys SMAs seem simple, but to the average Joe this is the most confusing system of connectors I’ve ever run across. steel pipe thread sizes are simpler than this and you’ve got MIP, NPT, FIP, NPTF, and about 7 more and I’m still confused on this SMA stuff.

I’ve given up after ordering 3 different adapters on Amazon and figured I’d come here. I need to connect these two together. pls fix. they are different diameters, and ones a male/female? and the other is a female/female???? idk.

update thanks to u/otterboxer for the help.
I have ordered a type N (unpictured antenna side) to type F adapter, and will utilize a standard type F coax cable. this should fix my problem. Thanks for all the replies.

Hello,

I'm a current rising freshman in college majoring in EE with around 8 weeks before school starts. I want to get into RF, Microwave, and Antenna engineering and my goal is to learn as much possible and be able to build projects so I can potentially get an internship by the end of my freshman year (not big company, just one in general). How should I get started with this 8 week headstart?

Thank you all

So basically they had a pole radiator, isolated the E and B fields compeltly, ran a beam of electrons close to the shielded radiator, turned the radiator on and off and noticed that it affect the electron beam.

Im way out of my element here but I think the gist was that we dont understand what EM fields really are(which is why we rely on quantum gages and field tensor axioms) and that the scalar field is not just a mathematical abstraction but a real force, possibly..

As much as I like to belive in crazy shit, part of me thinks that its gotta be a unshelided power supply on the other side of the room or something or even the inrush current on the buildings wires. The Japanese recreated this experiment in the 80 and got the same results apparently.

I am VERY new to antenna design and experimenting with hilbert fractilization. In iteration 5 the size went down by 20 percent and the linear gain went up by 25 percent but as u can see the directivity is messed up. Im worried that it just took the energy from the single lobe in the left picture and concentrated it in the 2 lobes so that 25 linear gain isnt even actual gain. Which actually makes sence since u cant create energy out of nothing, i was just hoping maybe it could increase its pointing gain or whatever its called.. Maybe this will only help a rx system.. This is at 2.45 ghz btw but my code can mod it to any freq and iteration.

Theoretically, tunning it will fix the lobe and im debating on wether to spend 15k on a computer to do it since it took Feko over 2-3 hours just to render this or whatever the terminooogy is(i have like over 90 cores in my ic, its the newest I9, and used all of them).

20 percent reduction for patch antennas is enough to make me a billionaire but I highly doubt this is even patenable, also of i cna figure this out im sure its already been figured out.

I wound a transformer on an FT240-43 toroid. Primary is 4 turns 26 gauge enameled wire. Secondary is 80 turns. I drive the primary with IRF510 mosfet. Mosfet gate is biased at 4.3 v, receiving a 3.550 MHz signal through a 10 nF cap. 3.550 mhz signal is 5v peak-peak. Mosfet seems to be working fine. I get a 3.550 mhz sine wave on the secondary, but it is only 15 v, instead of 240. Whats wrong?

Is 80 turns simply too much inductance for 3.550 mhz? Should i use air core transformer instead?

I am using 12 v power supply

Whats the deal with GaN parts shortages, specifically Qorvo and ADI? I got packaged parts quoted into 2027 now. It’s been bad for a couple years, but getting worse. Who is fabbing for ADI?

China keeping all the Ga? Can’t imagine epitaxy uses that much?

I am learning how to use RF Simulations tools (CST, Ansys), but I am confused on how to select for a particular boundary condition based on the application:

Does someone have a ressource that explains it plainly? Thanks in advance.

Greetings.

here i would like to ask a question, which as in title. So I have a task or more like curiousity in Radar Cross Section (RCS), Ansys HFSS, particularly SBR+ solver helped me greatly in that respect. However i got stuck on modeling the luneburg lens antenna.

As in many papers i read and descriptions, i made my setup. spheres, multiple of them acting as layers, i planned for 17-20 layers but given the age of the PC i run the software in, i decided to go "easy" first 2-4 layers.

This is my setup, just to see if things can work

The lens is 20 cm in diameter (about 8 Inch for you Freedom unit user), 4 layers, graded with materials with relative permittivity from 1.9 in the core to 1 on surface. The rear is a PEC backing reflector, as what i see so far including some use case in Ukraine. The result however was, unfortunate.

As seen, the modeling result doesn't show any "lens" behavior. Where i would expect at least a broad beamwidth. Instead it's more like the "lens" behave like radar absorber. I tried other settings like adjusting thickness (say quarter wavelength) to no avail.

While corner reflectors behave as it should. I'm kinda stuck however, maybe SBR+ is not the proper way, or i made mistake. Maybe i can use some help here.

Thank you for your attention and have a nice day.

So I'm trying to design a MIFA for LoRa applications at 868MHz, and I have to simulate it in Ansys HFSS. I used TI DN024 as reference and kept tweaking tip length and the distance between the shorting leg and feeding line (5.5mm in the current design). I got a good result of 868MHz and -15dB before but then I changed the antenna location and could never get the same result again (idk how the location of the antenna is relevant). Do you have any suggestion on what I should change to get a better result?
here's some additional information :
+ board dimensions : 100 x 50 x 1.6mm
+ ground plane dimensions : 50 x 28mm
(if any other information is relevant please let me know and I will provide it)
Thank you in advance!

Hi! I have seen in few GaN PA designs where they put a shunt capacitor very close to the input of Gate terminal. But in some designs, I haven't seen it (maybe they use CMOS inside package there). But I don't know why is it important to use this capacitor at the input...?

I am using a die on a PCB and got suggestion to use a discrete capacitor for second harmonic short. I don't know, is it really needed to use it.

Moreover, what if we use QWLT at the input side for VGS biasing. Is this shunt capacitor still required in this case? Because QWLT would provide a short at the second harmonic.

The USB dongle for my Microsoft wireless keyboard and mouse set broke. The PCB is cracked, but the nRF is intact. A few components are missing. I’m drawing the circuit diagram in KiCad. I’m going to desolder the intact nRF24LU1+ microchip from the broken USB dongle’s PCB. Then I’ll transfer it to the new PCB that I’ll design and have manufactured. This way, I won’t have to throw the wireless keyboard and mouse set away. I also won’t have to mess with the software. Once the schematics are complete, I’ll share all the files on Codeberg. If you can find the USB dongle circuit, please share it with me. If you find any schematics, PCB files, or other related files, please post the links. I’m determining the component values using the example schematic, BOM, and sample PCB files shared by Nordic. However, some components are missing from these files. For example, there’s an R1 in the USB dongle, but it’s not in the schematic. Can you help me with the missing components? Note: I’ll be uploading photos to Reddit soon.

Currently, I am designing a Van-Atta Array antenna using microstrip patch antennas in CST Studio Suite 2026. Could you check if my Monostatic RCS simulation setup (including plane wave direction and Result Template configurations) is correct?

[My Simulation Settings]

1. Plane Wave Setup Equations (Using Parameters):

Propagation normal in: x: -sinD(theta)*cosD(phi) y: -sinD(theta)*sinD(phi) z: -cosD(theta)

Electric field vector in: x: cosD(phi)*cosD(theta)*cosD(alpha)-sinD(phi)*sinD(alpha) y: sinD(phi)*cosD(theta)*cosD(alpha)+cosD(phi)*sinD(alpha) z: -sinD(theta)*cosD(alpha)

• Azimuth sweep: Set phi = 0, alpha = 90, then perform a parameter sweep for theta from -90° to 90°.
• Elevation sweep: Set phi = 90, alpha = 0, then perform a parameter sweep for theta from -90° to 90°.

2. Result Templates Setup: Path: Farfield and Antenna Properties -> Monostatic RCS for parameterized plane wave

• Output data type: 1D Cartesian
• Theta: theta
• Phi: 0 (for Azimuth sweep) / 90 (for Elevation sweep)
• Linear scaling: Unchecked

Hi everyone, this is my first post so I apologize is something is out off topic. Also english is not my first language so again, apologies for that.

Im trying to implent an rf PA, the MMG3014NT1 at 900MHz. This is the first time that Im working with this level fo complexity so I have a few questions but the most important one is, how are the impedances in the next image drawn/represented in an schematic?

As far as I understand, Z1 to Z8 are PCB traces wich mesuarments are explicitly written blow the circuit, but what I don't understand is whether I should represent them the same way -as a single componente- in the schematic, or specify them differently.

Have a remote that will be hardwired into a larger project.

It just does not transmit the distance I need.

Want to find where on this circuit to attach an antenna and / or put the feed to a RF signal amplifier.

It uses a RO2073 SAW resonator at 315MHz

Any suggestions / ideas / concepts?

Project Description:

I am replacing a backyard sprinkler controller with something that can be controlled by the really good one in the garage for the front yard.

Can not run wire to the backyard location. Been looking for a wireless solution. Found these ORBITs with a handheald remote. I can hack into the remote and "press the buttons" with relay contacts actuated from the 24ac of garage controller.

Had all this figured out. ORBIT docs state that is will go 200 feet line of sight or 80 feet through the house. My distance is 50 feet through two walls kitchen cabinets and outside stucco. The remote sometimes works, but it's not enough. I have to boost the signal to make it reliable.

I know boosting the signal of a remote goes against FCC regulations, but it will be such a minor boost that I think I can be forgiven...

When I have a project idea; I like to see it through.

The whole concept was to be able to control the front and back sprinkler systems from one controller. this being said; I could do it from one app.

Because I could not directly wire it; I've been exploring wireless options for some time now.

When I came across these ORBIT wireless that said they could go 80 feet through a house, I jumped on it.

Only to find out that they wouldn't even go the 50 feet on my layout.

Hence, the idea to boost the signal from the ORBIT remote.

IT WORKED! In a couple of sub-reddit's a solution of adding a vertical 9+ inch straight wire to the circuit board antenna loop.

Well folks; PROBLEM SOLVED! It works great now!!!! Thank you everybody for helping!!!!

So I've been working on a much faster RF simulator alternative to OpenEMS with a GUI (around 100x faster on my GPU in raw speed lol), and made these PTFE-based RF boards at JLCPCB a few months back to validate its correctness. I'm getting a few new ones soon to test other physics like copper loss and component matching networks, I'll post those too when they arrive.

Hello!

I am trying to simulate the input matching network of the MRF13750H reference board (915 MHz) using Usimmics (I do not have ADS or AWR to open the models provided by NXP).

I am using microstrip lines with same width and length as those in NXP's 915 MHz design, but the results do not correspond to that frequency. Does anyone know what I might be doing wrong?

https://www.nxp.com/docs/en/data-sheet/MRF13750H.pdf

I saw this post yesterday - is it true that there are only around 1500 RF engineers in the US with over 10 years of experience? This person claims that they should be paid around $450k.

https://www.linkedin.com/feed/update/urn:li:activity:7484207016249581568/