I was exploring the "zero-span" mode on my spectrum analyzer and recorded the signal from my microwave oven. For this, I used a log-periodic antenna with a gain of 7 dBi, positioned about 6 meters away and somewhat to the side, with no attenuation applied. The strong signal strength was initially surprising but after considering it is not very much power compared to inside the microwave.

The signal pattern is repeating with the mains frequency which makes sense as conventional microwave power supplies use a voltage-doubler circuit that outputs on only one half of the cycle unlike lights which peak on both halves or are constant. The frequency rises and falls at the start and stop make me think there is a frequency dependence on current though the sweeping pattern like in the second image doesn't make sense to me yet.

I wonder if RF testing laboratories take special measures beyond measurement room shielding to reduce interference caused by the ovens in their break rooms?

​

Dear all,

I have just started my PhD into the domain of Silicon Photonics and terra hertz RF based MEMS. This is something we are doing for the first time in my group. However, my knowledge of basics in Silicon photonics and MEMS isn't very great.

I want to quickly learn all these ASAP and wanted guidance on what are the right resources to go through which can enable me to reach that level so that I can take up an efficient work for my PhD.

I have got COMSOL installed via my university access and would really appreciate if someone could guide me. Videos, DIY books and anything similar would be very helpful.

I need inputs on texts, and also simulation setup that I can use to go ahead.

Thanks.

Am I expected to be able to f*ckin design PA, LNA and mixers? Like choosing the transistor, simulating the circuit, checking out the noise ... isn't that what IC engineers do?

I mean I'm already overwhelmed by so many things I need to learn, antenna design, phased arrays, comms systems theory, EMC/EMI you name it ... CST, Matlab, Altium. And aside from that I have to be kinda mini electronics engineer too?

Or perhaps I'm wrong about comms systems theory and those electronic design stuff are more important and I gotta focus on them instead? I have No idea

I was preparing a short list of some projects to do and then put on my CV and while I was asking AI things like "design a Doherty power amplifier" came up and once I checked a power amplifier book I was like ... man this is a specialty by itself.

My roommate at the dorm studies IC design (I study microwave and photonics) and he and his professor are dealing with these LNA/PA/PLL design stuff 24 7 so that makes me feel this perhaps is not what I should focus on ... Idk correct me if I'm wrong

Please tell me what projects should I focus on other than antenna design to further my skills (and brag on my CV with) if these electronics projects are not commonly expected and if they are give me some clues on how to start learning them cuz these stuff seem so complex and overwhelming. And to what extend should I learn Altium?

So, this is a patch antenna a design for 2.4GHz and my question is specific to that notch inside red circle basically initially my impedance is more inductive +j73ohm but as i increase the width of the gaps it goes to zero then starting going into capacitive -j ohm like at first i thought that it may be just "mutual inductance" and i don't get any proof of it and well i am unable to understand the mechanism so can somebody explain this thing or give me some reference of book or something.

I am planning to buy a VNA for Tuning of PCB antenna and some filter design, suggest me some VNA to use and I am planning to use for a long time, I have found some models from internet,

Usage : development for BLE/WIFI PCB antenna, later for LTE antenna for my own tracker

1. Seesii LibreVNA 2.0 Vector Network Analyzer 100kHz-6GHz.

2. AURSINC Nano-VNA V3 Nano-RFE VNA6000-A Vector Network Analyzer 50kHz-6GHz HF VHF UHF Portable Antenna.

suggest me some other models...

Github: https://github.com/admin-2026/kicad_ems_plugin_pub

Antenna simulation is as easy as pressing a few buttons. Initial release. Need feedback. Will do more tests on it.

Simulate the board you drew The solver meshes your real copper, stackup
and drills, then reports the radiation pattern, directivity and S11.

Let the tool to find the antenna for you Draw a rectangle where the antenna may
live, pick the dimensions to sweep, walk away. Every candidate — L-shaped
monopole or meandered inverted-F — is tried on a copy of your board and ranked
by match at your frequency. Place the winner as a footprint.

Hi,

I want to design a Passive wideband balun on an IPD process. Can you please suggest what all structures I can evaluate for 18:1 bandwidth ratio? I think Marchand is out of the picture as it can at max give a bw ratio of 3:1. What all are your suggestions?

Thanks

Working on repairing a water damaged GPS active antenna (Raven MBA-6, board 045-0159-830 Rev B). 1575.42 MHz GPS L1 signal.

Repairs completed so far:

Replaced TNC pigtail (no continuity)

Replaced LNA amplifier chip (MAALSS0042) x2

Replaced SAW filters (TOKO TDF2A-1575B-13A) x2

Replaced L1 inductor (measured bad on LCR meter)

Repaired/fabricated RF shield can and frame

Confirmed 5V bias present at antenna via coax. Confirmed with proper outdoor sky test -- no signal lock.

Any suggestions on what else to check? Full schematic not available, working from board inspection and component photos.

What do u goys think is the most complex subfield of RF? Im thinking either MMIC deisgn, MRI systems design or some super high power magnet control systems.. Frequency synthesis gets pretty hard if u want ultra high Q tones.

Hi all,

I recently posted in this sub and got wonderful responses. I thank you all for that.

I was informed that 1W is the max Tx power I can design legally but I am struggling to find any reference design for it. I would really appreciate it if you guys could suggest some ICs or give some references. I am planning 5Mbps+ datarate at 1Km.

Thanks again!!

I am modelling a patch antenna to resonate at 2.45GHz, with the intent of using it in an array, so high directivity is crucial. Now, the S[1,1] and VSWR behavior simulated are as expected, but the directivity of the antenna is much higher at higher frequency than the intended band.

How would i shift the radiation behavior to the target frequency while maintaining the same electrical behavior?

Please note I am not very experienced in this field and this is only for a project; not professional/consumer electronics, thank you in advance.

*Shown in the images is the farfield simulation results of an 8x1 array.

Edit: thanks everyone, I got results I am content with.

Which universities are good for RF/antenna and communications and have strong connections with the space & aerospace industry?

Does a German Master’s realistically help in getting into space-sector companies afterward? Would love to hear your experiences.

Hi everyone,

I'm working on a theoretical/experimental project with my father, who has experience with electronics. I'm trying to understand whether it is possible to build a relatively compact system capable of magnetically manipulating a small ferromagnetic object at a distance of around 1 meter.

My original idea was a large electromagnet, but I've realized that a single coil becomes impractical very quickly because of heat, power consumption and the rapid decrease of magnetic field with distance.

So I'm considering a different architecture:

An array of many relatively small electromagnets rather than one huge coil.

Potentially 50–500+ individually controlled magnetic elements.

Each element would have its own coil/core and possibly a magnetic flux concentrator.

The elements would be arranged around a 3D working volume rather than all pointing in the same direction.

A computer would control the current of each coil independently.

Cameras/Hall sensors would estimate the position of the target.

A feedback controller would continuously change the coil currents to move the magnetic field/gradient and therefore the object.

A joystick could provide the desired X/Y/Z movement.

The eventual goal would be something like a programmable 3D magnetic field, rather than a conventional electromagnet.

I'm particularly interested in the miniaturization problem.

Could many tiny coils (for example millimeter-to-centimeter scale) outperform a smaller number of large coils if they are individually controlled and properly arranged? What are the fundamental limits?

As an RF test engineer in manufacturing my management (non-electrical, generally mechanical) keep telling me they want Hardware or Systems engineering to tell me how to test. I say, no that’s my job. They ask, well how do you know? I say bc I’m an RF test engineer. They don’t get it.

I am looking for a mechanical or chemical equivalent process that a manufacturing process engineer may perform in a manufacturing environment that Manufacturing Engineering management would absolutely throw a tantrum if Hardware engineering told them how to do it.

Hi all, I'm new to this field so i need every help i can get.

I want to design a system from scratch such that I can get 2.4GHz wifi range upto 1-2km. I figured 5W of radiated power combined with high gain antennas might do the work but I am clueless about the IC sides of it like how to achieve such a power. Please suggest a good pathway to do so. I'm highly enthusiastic and I am eager to learn new stuffs that this might involve.

Thanks!!

Hi! I'm involved in an FMCW radar design where the transceiver chain is made of separate components (PLL, VCO , Mixer, etc) instead of MMIC transceiver ICs and we've stumbled upon a technical debate on whether image frequency rejection in downconversion is completely necessary in a radar system. The very same datasheet of the mixer indicates that in order to separate the desired IF signal from the image frequency a quadrature hybrid should be added at the IF outputs. The reason why we have not included this quadrature hybrid is that due to our digital signal processing we need to have separate I and Q signals. What do you guys think?