A bit of background, I'm a 17 year old nerd from Finland, and I've been tinkering with electronics for around 5 years now. I recently (around 6 months ago) got into the RF side of things, through SDRs and satellite reception. But now I'd like to learn about actually understanding how stuff works. The way I learnt electronics was mostly stumbling my way through it, and not really "studying" stuff. How should I get into RF? Is there any projects I could just follow along?

Hi, I thought i would try messing with some RF as i have avoided it in the past. This is my attempt at a 32MHz Colpitts oscillator, and I'm getting no luck.

I first tried replacing the 22uH inductor with a 270 ohm resistor, as I realized the self-resonant frequency of my inductor was only 15MHz. This did not help oscillation. Next I tried increasing C2 to 680pF as many Colpitts i see have a larger capacitor here, presumably to stabilize the operation a bit and load the collector less. This still did not work.

The tank inductor is 10mm diameter, 15mm long, 6.5 turns, should be about 214nH according to https://m0ukd.com/calculators/air-cored-inductor-calculator/
Wound with 0.2mm wire, as it's what i had on hand.

When power is applied, the collector stays at 5V (with 22uH inductor) / 3.68V (with 270R). The base is at about 1.26V, emitter at .56V.

I've built a Colpitts with a more primitive design a while ago at 1.3MHz, worked perfectly first try on protoboard, I did not figure stepping up to 32MHz would be this much harder, although there's probably something obviously wrong here, after all I haven't ever gone past that 1.3MHz oscillator.

Hi everyone,

I’m starting passion project that may turn into product: medium-cost Vector Network Analyzer capable of reaching 20 GHz.

As we all know, commercial units at these frequencies are incredibly expensive which makes it nearly impossible for hobbyists, students, or small startups to get their hands on high-quality data. My goal is to bridge that gap by designing a unit that maintains good performance while keeping the price point accessible.

I’ve started a build log here (empty for now): https://patryksi11.github.io/20ghz-vna-blog/

I want to make sure I’m building something that people actually want to use. I’d love to hear from the community:

1. What is your "must-have" feature?
2. Price Point: How much are you willing to pay for 20 GHz VNA?

I'm trying to balance "good performance" with "affordable manufacturing." Any feedback is appreciated!

EDIT: To give everyone a clearer picture of the project scope, here are the intended specs:

Form Factor: Similar to the Libre VNA (no integrated screen; just ports and USB/Ethernet connectivity).

Configuration: Full 2-port VNA.

Frequency: 20 GHz capability on the fundamental frequency (No harmonic mixing).

Limitations: No output level adjustment (keeping the design as minimalist as possible).

I’m developing a low-cost, multi-band Direction Finding (DF) system specifically targeting commercial and custom drones comm signals

Most commercial counter-drone solutions rely on multi-channel phase-coherent receivers, making them prohibitively expensive.

My goal is to build a high-performance single-channel receiver that combines Amplitude Comparison, Pseudo-Doppler Phase Shift, and RF Signal Classification.

Target ISM/GNSS Bands

900 MHz (902–928 MHz telemetry)

GPS/GNSS L1 (1575.42 MHz)

2.4 GHz (WiFi/OcuSync/ExpressLRS)

5.8 GHz (FPV / OcuSync)

A single receiver channel significantly reduces cost and calibration drift, but standard RF switching introduces transient phase glitches during FHSS hopping. Below is the refined system architecture using band-specific front-ends and a pseudo-Doppler RF switch loop:

Looking For:

Technical Partners: RF Hardware Engineers (PCB layout for 6GHz RF front-ends), FPGA/Zynq Developers (DMA, custom IP cores for Doppler demodulation), and DSP/ML Engineers (protocol classification).

If you’re interested in collaborating, send a DM!

I am currently in the brainstorming phase of designing this TX/RX FM project. I plan to use an ESP32 and then RDA5807 for RX and KT0803I for TX, would a PAM8406 be good to drive 2 (stereo) 3w 4 ohm speakers? How can I power it on batteries without unwanted RF noise?

Hi, RF newbie here. I am an IT database engineer and data analyst. I play badmington, tennis, and pickleball, all in doubles. In doubles, there is a lot of analysis on team formation and partner separation distance. I am thinking about using UWB boards to track player positions. I would like about 5-10 observations per second, for all 4 players. The UWB board I have in mind is Qorvo DWM3001CDK, which retails at about $30. I would get 4 boards as anchors and 4 boards as player tags. Then I like one more board as the data collection gateway, and have it tethered to a Macbook via USB cable. During a game, data would be streamed into the Macbook.

The tags would need to be programmed so they send a data packet every 2-5 seconds, to the data collection gateway board. The positions don't need to be super accurate. I think 15-20 cm will do the job.

Plz help me understand whether this setup is feasible. What additional factors should I be thinking about? I hope to use this setup both indoors and ourdoors. I am aware that UWB signal cannot penetrate human body because it is mostly water. I will use enough anchors so each tag has clear line of sight to at least two to three anchors.

I'm in my junior year of college and I still haven't landed an internship. For context, I am an EE major with a decent GPA(3.5) and one independent project, which is a 900 MHz bandpass filter I designed and simulated (still haven't had the opportunity to do the PCB, have it fabricated, or take measurements with a VNA)

As it currently stands, my interests are mostly in the realm of wireless communications/RF and analog electronics. My school rarely offers RF classes, so any learning I would be doing would have to be done independently.

Do I have a realistic shot of landing an RF internship for this upcoming summer? if not, what can I do in the meantime that will improve my chances? are there particular RF topics, projects, or skills that would be especially valuable for an undergraduate trying to break into the field?

Thank you

Hey guys,

I’m very interested in diving into radar systems and communication technology as an engineer.
I was wondering how to Beginn. Any recommendations?
My background is from control systems, so I know what Fourier transform is for instance.

Thanks

seeing the recent news with astera and progress towards AGI , has me a bit worried about a career in electronics/RF engineering in general

should i just shift my focus towards more management type roles and leave the R&D/academia research dreams aside?

some more info/clarification/discussion on this whole ai and EE intersection topic would be nice aswell

hoping this post could add some confidence back into me becuase the news i am reading now is just gloom and doom

thats all thanks.

This antenna is 35.3 from tip to tip of the circle and distance between the loop is 2cm, i wanna do 433mhz bidirectional communication with this antenna, I was planning to build a yagi uda with this of 5 directors, I dont know much about rf and i have just been following tutorials, I could only find 2mm hard aluminum wire so i used that to build the antenna, are there some things i have to look out for before connecting it to my telemetry radio (its a drone telemetry that uses MAVLink for bidirectional communication) Oh and the distance between two wires in end is 1cm.

Hi everyone,

I’m facing a bit of a career dilemma and would love some perspective from senior engineers in the industry.

To give you some background, I finished my PhD 3 years ago at a European university. My dissertation focused on developing large phased array antennas—mostly EM simulation, radiator design, and that side of things. During my PhD, I closely collaborated with a local defense contractor, and I really wanted to join them as an employee after graduating. My supervisors from the company even recommended me to the head of the antenna group. However, despite holding Western European citizenship, my non-EU birth and early childhood background triggered strict security clearance roadblocks, so they couldn't offer me a position.

Right after my PhD, I joined a commercial satellite company where I have been working for the last 3 years. I'm currently a Senior RF Engineer, working on a massive project developing a multi-thousand-element phased array. Despite my PhD focusing on antenna radiators, I also had a solid grasp of RF electronics fundamentals and a strong interest in the field. Because of that, my manager put me on the RF frontend design team so I could bridge the hardware and antenna domains. We already have a dedicated, veteran antenna engineer handling the radiator design, and because the project is in full swing, management won't move me to a different role in the middle of it. In my current role, I work as a frontend design engineer while also supervising, mentoring, and guiding two junior RF engineers.

While the work is interesting, my day-to-day is almost entirely RF electronics. I really miss the core EM and radiator design work I did during my PhD, which is what I actually find fulfilling. My manager has promised to consider transitioning me to an antenna role once this current project phase wraps up in next 3-4 years, but I'm starting to worry about my long-term positioning.

A few specific things are on my mind:

First, if I stay here working on the frontend for another 3-4 years, am I going to get permanently pigeonholed as an "RF Engineer"? I'm worried it will get harder and harder to pivot back to core antenna array design the longer I stay away from it.

Second, does system scale matter more than the exact role type? Is it better for my resume to stay on a highly complex, massive array project even if I'm on the frontend side, or should I jump ship to a company designing smaller, simpler antennas just to get back into core EM design?

Third, given my current title, if I try to move over to a pure antenna role at a new company, will I be forced to take a step back to a mid-level or junior role because my recent industry experience is on the frontend? Or does the combination of a phased-array PhD and senior system-level experience carry over to a senior antenna position?

Finally, the European market feels a bit restrictive. Because of my security clearance limitations, I have to stick entirely to the civil/commercial sector (commercial aerospace, satcom, or telecom).

Are there any specific companies or commercial hubs you would recommend targeting in Europe that work on ultra-large phased array designs but operate purely in the civil domain? And for anyone who has made a similar pivot—how do hiring managers view frontend work on a massive phased array versus basic radiator design for smaller antennas?

Thanks in advance for any insights or advice you can share!

(Note: This post was written by me with the help of AI to protect anonymity and organize my thoughts clearly.)

I am attempting to simulate (OpenEMS) the reflection and transmission in a PCB that uses grounded coplanar waveguides (via via's) with a soldering pad discontinuity. The resulting S11 and S21 values do however not seem realistic to me. I included pictures of the geometry below:

Green is the top ground, pink the dielectric, purple the signal path and brown the vias.

clear; clc; % Initialize CSX structure CSX = InitCSX(); %% 1. Key Physical & Simulation Parameters f_mesh   = 4.5e9;  % Max frequency for grid resolution calculation f_center = 2.9e9;  % Gaussian excitation center frequency f_bw     = 1.4e9; c0 = physconst('LightSpeed'); % Speed of light (m/s) % CPW Dimensions (all in mm unless specified) h_sub   = 0.254;   % Substrate thickness eps_r   = 3.48;    % Substrate relative permittivity w_trace = 0.5;     % Standard signal line width gap     = 0.2;     % Gap between signal and coplanar ground t_metal = 18e-6;   % Copper thickness (18 um) - only used for vias now via_dia = 0.6; via_pitch = 1; via_step_gap = 0.5;  % was 0.1 -- tune this down if grounding integrity suffers % Domain boundaries x_min = -20; x_max = -15.95; y_min = -6;  y_max = 6; z_min = -h_sub; z_max = 0; %% 2. Define Materials CSX = AddMetal(CSX, 'cpw_cond'); CSX = AddMetal(CSX, 'cpw_gnd'); CSX = AddMetal(CSX, 'vias'); CSX = AddMetal(CSX, 'bottom_ground'); CSX = AddMaterial(CSX, 'my_substrate'); CSX = SetMaterialProperty(CSX, 'my_substrate', 'Epsilon', eps_r); %% 3. Define Geometry % Substrate CSX = AddBox(CSX, 'my_substrate', 1, [x_min, y_min, z_min], [x_max, y_max, z_max]); % Signal conductor line segments CSX = AddBox(CSX, 'cpw_cond', 2, [-20,     -0.25, 0], [-17,     0.25, 0]); CSX = AddBox(CSX, 'cpw_cond', 2, [-17,     -0.75, 0], [-15.95,  0.75, 0]); % CSX = AddBox(CSX, 'cpw_cond', 2, [-15.75,  -0.75, 0], [-14.7,   0.75, 0]); % CSX = AddBox(CSX, 'cpw_cond', 2, [-14.7,   -0.25, 0], [-12.2,   0.25, 0]); % Coplanar Ground Planes (Top) CSX = AddBox(CSX, 'cpw_gnd', 2, [x_min, 0.25 + gap, 0], [-17 - gap, y_max, 0]); CSX = AddBox(CSX, 'cpw_gnd', 2, [x_min, y_min, 0], [-17 - gap, -0.25 - gap, 0]); CSX = AddBox(CSX, 'cpw_gnd', 2, [-17 - gap, 0.75 + gap, 0], [x_max, y_max, 0]); CSX = AddBox(CSX, 'cpw_gnd', 2, [-17 - gap, y_min, 0], [x_max, -0.75 - gap, 0]); % CSX = AddBox(CSX, 'cpw_gnd', 2, [-14.7 + gap, 0.25 + gap, 0], [x_max, y_max, 0]); % CSX = AddBox(CSX, 'cpw_gnd', 2, [-14.7 + gap, y_min, 0], [x_max, -0.25 - gap, 0]); % Bottom Ground Plane (GCPW)  CSX = AddBox(CSX, 'bottom_ground', 2, [x_min, y_min, z_min], [x_max, y_max, z_min]); % Vias  for i = -19.4 : via_step_gap + via_dia : -17 - gap - 0.2     CSX = AddBox(CSX, 'vias', 2, [i, -via_pitch/2, z_min], [i + via_dia, -1*via_pitch, 0]);     CSX = AddBox(CSX, 'vias', 2, [i, via_pitch/2, z_min], [i + via_dia, 1*via_pitch, 0]); end % for i = -17 + gap : via_step_gap + via_dia : -14.7 - gap %     CSX = AddBox(CSX, 'vias', 2, [i, -via_pitch - 0.5, z_min], [i + via_dia, -via_pitch/2 - 0.5, 0]); %     CSX = AddBox(CSX, 'vias', 2, [i, via_pitch/2 + 0.5, z_min], [i + via_dia, via_pitch + 0.5, 0]); % end %  % for i = -14.7 + gap + 0.2 : via_step_gap + via_dia : -12.8 %     CSX = AddBox(CSX, 'vias', 2, [i, -via_pitch/2, z_min], [i + via_dia, -1*via_pitch, 0]); %     CSX = AddBox(CSX, 'vias', 2, [i, via_pitch/2, z_min], [i + via_dia, 1*via_pitch, 0]); % end %% 4. Define Lumped MSL/GCPW Ports (Vertical Excitation) % Port 1 (at X = x_min) [CSX, port{1}] = AddLumpedPort(CSX, 2, 1, 50, ...     [x_min, -w_trace/2, z_min], [x_min, w_trace/2, 0], [0 0 1], true); % Port 2 (at X = x_max) [CSX, port{2}] = AddLumpedPort(CSX, 2, 2, 26.82, ...     [-15.95, -1.5/2, z_min], [-15.95, 1.5/2, 0], [0 0 1], false); %% 5. Non-Uniform Mesh Generation (Optimized) lambda_min = c0 / (f_mesh * sqrt(eps_r)) * 1000; % Minimum wavelength in substrate (mm) max_cell = lambda_min / 10;                  % Global max cell size (~2.12 mm) % Only detect edges from the traces/grounds/substrate, NOT the vias. % forcing sub-mm cells across the entire via region in x. Excluding vias here mesh = DetectEdges(CSX, [], 'SetProperty', {'cpw_cond', 'cpw_gnd', 'bottom_ground', 'my_substrate'}); % Manually add mesh lines bounding the via regions so the solver still % resolves the via fence approximately, without following every via edge. via_region_x = [-19.4, -17 - gap - 0.2, -17 + gap, -14.7 - gap, -14.7 + gap + 0.2, -12.8]; mesh.x = unique([mesh.x, via_region_x]); via_region_y = [-via_pitch, -via_pitch/2, via_pitch/2, via_pitch, ...                 -via_pitch-0.5, -via_pitch/2-0.5, via_pitch/2+0.5, via_pitch+0.5]; mesh.y = unique([mesh.y, via_region_y]); % Define target resolution rules mesh.x = SmoothMeshLines(mesh.x, max_cell, 1.4); mesh.y = SmoothMeshLines(mesh.y, max_cell / 2, 1.4); % z now only needs to resolve substrate thickness + via depth (both already % bounded by z_min and 0); no more 18 um top-metal sliver forcing fine cells. mesh.z = SmoothMeshLines([z_min, 0], max_cell / 2, 1.4); % Add Air padding around the structure air_padding = lambda_min / 4; mesh.x = [mesh.x(1) - air_padding, mesh.x, mesh.x(end) + air_padding]; mesh.y = [mesh.y(1) - air_padding, mesh.y, mesh.y(end) + air_padding]; mesh.z = [mesh.z(1) - air_padding, mesh.z, air_padding]; mesh.x = SmoothMeshLines(mesh.x, max_cell, 1.3); mesh.y = SmoothMeshLines(mesh.y, max_cell / 2, 1.3); mesh.z = SmoothMeshLines(mesh.z, max_cell / 2, 1.3); CSX = DefineRectGrid(CSX, 1e-3, mesh); % Convert mm to meters %% 6. Setup FDTD Solver Parameters FDTD = InitFDTD('EndCriteria', 1e-4); FDTD = SetGaussExcite(FDTD, f_center, f_bw); % CHANGED: PML depth reduced from 8 to 6 cells on all boundaries. Verify % against your previous PML_8 result that S11 noise floor is unaffected; % if so, this is a straightforward cell-count reduction with no accuracy cost. FDTD = SetBoundaryCond(FDTD, {'PML_8', 'PML_8', 'PML_8', 'PML_8', 'PML_8', 'PML_8'}); % Save data file mkdir('temp'); WriteOpenEMS('temp/test.xml', FDTD, CSX); % Display 3D model CSXGeomPlot('temp/test.xml'); %% 7. Post-Processing: Calculate and Plot S-Parameters freq = linspace(1e9, 3.8e9, 401); % Frequency sweep from 1 GHz to 3.8 GHz % Read port voltages & currents port = calcPort(port, 'temp', freq); % Extract S-parameters s11 = port{1}.uf.ref ./ port{1}.uf.inc; s11_db = 20 * log10(abs(s11)); s21 = port{2}.uf.ref ./ port{1}.uf.inc; s21_db = 20 * log10(abs(s21)); % Plot Results figure('Name', 'S-Parameters'); plot(freq / 1e9, s11_db, 'r-', 'LineWidth', 2); hold on plot(freq / 1e9, s21_db, 'b-', 'LineWidth', 2); grid on; xlabel('Frequency (GHz)'); ylabel('Magnitude (dB)'); title('GCPW Circuit S-Parameters'); legend('S_{11} (Reflection)', 'S_{21} (Transmission)'); ylim([-40 5]);

As an experiment I decided to swap the inductor with a crystal at 4mhz at first nothing worked at all after removing the capacitors the circuit started oscillating beautifully even though the feedback wasn’t even properly connected. After connecting the feedback the oscillation persisted but with significant distortion connecting the capacitor resulted in the waves seen here. The really missed up part is that when I adjust the oscilloscope to work with 100msps it shows a wave around 4mhz but I decrease the sampling rate to 500ksps it shows a wave at 480hz.

so i made my antenna in student license but while simulating i got hit by the mesh limit, so i wanted to simulate it in a licensed version in my college desktops but apparently student version files cannot be opened in the commercial version. Any workaround to convert or do i just have to recreate again in the commercial version??

Hi, I'm currently working on a hobby project with a large prime focus satellite dish, that I can't get a feedhorn for. Making the feedhorn isn't a problem but connecting it to the LNB is a bit more difficult. I need to make an adapter to go from an odd diametre to a WR-75 compatible mount for the Ku-Band LNB.

I drew two versions of the same adapter in CAD and I'm wondering which one would be better? The top one uses tangential swep-blend avoiding discontinuity, and the other one is much simpler using just a linear transition. The linear one is of cause much easier to manufacture than the tangential one.

Which one should I go for? Would they perform the same or would this create impedance problems or reflactions or high attenuation? I'm a mechanical engineer, not a RF engineer so this is more like magic to me at this point to be honest.

It no works, not sure exactly why? And why the frequency is way off than what it should be (around 2 MHz) but hey something is always better than nothing.

Edit: I think I flipped c1 and c2 in the diagram.