Hey everyone, I recently got an on-campus offer as an RF Radar Engineer at a startup. I'm currently finishing up my M.Tech in RF Design from a Tier-1 college. The new job is mostly focused on the passive devices side, but I really want to switch over to RFIC design in the future. The catch is, I don't have a lot of background in RFIC yet.

How should I balance this job while preparing for an RFIC transition? I would really appreciate a complete roadmap—specifically, what core subjects I need to learn and what kind of hands-on projects I should add to my CV.

Was simulating the rf pcb board which has 16 layer stack up and around 500 ports in one layer

So now if I have to draw a rectangle with one end gnd and the other edge at trace and then assign lumped ports is too long job

Any suggestions?

Pls help!!!!!!

Hi guys,

I have designed a PCB-based power amplifier using Keysight ADS.

After I fabricate it and perform an initial CW sweep, I found the frequency shifted from 3.5 GHz (in simulation) to 3.3 GHz (measurement).

I wonder how do I model this frequency shift in the simulation, or I just tuned the board based on the 3.3GHz results? Previously, I just directly tuned the board instead of going back to the simulation to model this issue. I wonder if there is a better way to do it.

When I say 'better,' I mean the simulator should guide me to the exact place on board to touch.

What is your suggestion?

Thank you!

Hi, for purposes of building RF switches in HF band, is it just me or do PIN diode datasheets not contain any useful information? E.g one out of ten I found had a plot for Ron vs frequency, and not a single one mentioned the minority carrier lifetime at all.

Of course this probably isnt every datasheet, but has anyone else noticed this trend?

And also, for people who have made ham frequency switches with these, how do you pick them if they dont mention anything in the datasheet?

My initial assumption is that a yagi-uda with 20dBi gain, is simply filtering out the radiation coming from directions other than that with peak gain and doesn't actually "catch" more radiation from that direction than a regular dipole? Meanwhile the reflector design "catches" a large surface area of parallel radiation and condenses it at the feed, meaning it performs BOTH tasks of filtering out non-incident radiation AND collecting more radiation from the direction of highest gain?

But If that were the case, and I must assume I just misunderstand how dBi works, then wouldn't the simulations for a yagi-uda just have 0dBi in the target direction but massively negative dBi in other directions instead of say, +20dBi in one direction, and then falling off to single digit and negative figures off-axis?

If somehow the yagi "magics" extra energy despite not having more aperture, then I guess it's to do with the waves interfering with the parasitics and having more chances to interact with the EM field, and thus more energy is received?

Need some genuine career advice from people in semiconductor packaging/SI-PI roles.
Right now I’m working in an OSAT-type environment where my role is kind of a mix of Advanced Package Design and SI/PI. Over the last few years I’ve worked on things like:
• Advanced package/RDL/substrate design
• High-speed routing
• SI/PI simulations and debugging
• UCIe/LPDDR/HBM related issues
• Package bring-up and coordination with different teams
• A bit of NPI exposure too
The problem is I’m now at a stage where I need to decide whether I want to go deeper into SI/PI specialization or move more toward package design + NPI/program side responsibilities.
I currently have two offers:
1. AMD
• More SI/PI focused role
• Feels more aligned with deep technical work in high-speed/package architecture
• Slightly lower compensation
2. Broadcom
• More package design + NPI focused
• Better compensation
• But honestly, a lot of what I read online talks about very long working hours and higher pressure/workload there
Long term I want to stay in advanced packaging/interconnect technologies and maybe eventually move into areas like heterogeneous integration, photonics integration, advanced architectures, etc.
I’m honestly confused about which direction is better for long-term growth.
A few things I’d really like input on:
• Is going deeper into SI/PI a better long-term specialization?
• Or does package design + NPI open broader opportunities later?
• Which path tends to have better stability and growth in the industry?
• How different are the cultures at AMD vs Broadcom in reality?
• If you were early/mid career in this field, which one would you pick and why?
Would really appreciate advice from people actually working in these areas instead of generic internet opinions.

Hello everyone,

in my company we want to enhance the bandwidth of our analog circuits to 5GHz. Up to now we have been working with 2 layer FR4 PCBs. To minimize loss and noise contribution, we want to make the step to a material like Rogers 4350B. Furthermore, we would like to use a 4 layer stack up. While gathering information on costs on different online pcb calculators, I realized that Rogers 4350B seems to be common in thicknesses of 0.254mm and 0.168mm. A costeffective solution limits the spacing/clearance to 0.1mm. In my understanding it is importand to keep the microstrip mode as low as possible in a GCPW (Grounded CoPlanar Waveguide), and by this the ratio of the slot width G to the dielectricum heigth h. This leads to a cummulation of the rf energy in the slots and by this to lower loss and noise impact. So I'm a bit confused, why common dielectrics for rf pcbs seem to be have a low heigth as bigger dielectrics should lead to better signal qualities. Do I understand something wrong? Maybe someone can give a hint which Rogers 4350 heights he is using with GCPW?

thank you in advance for every comment.

I just participated in my first transmitter hunt. It was a lot of fun! I built a dual channel direction finder for 2 meters out of a Pico2 and about $5 in parts (FH146). Super fun little project! I found the handheld was best for getting me in the general area, but the direction finder made it pretty easy to pinpoint the transmitter.

If you've never tried a transmitter hunt, I highly recommend trying one!

Hello everyone,

I'm someone with a background in control systems (e.g. PID, LQR, MPC) and am currently doing a master's in said field. Recently I've gotten interested in RF and was wondering what are some applications of control theory in the RF domain. I'm considering taking some electives in RF related stuff to get some domain knowledge but I'd like to know if that would be useful for someone with a controls background.

Thanks in advance!

Hello everyone,

I’m currently working on a project to build a GPS tracker for our pet. I know there are some on the market, but they don’t quite meet our requirements.

The device connects three different antennas: a LoRaWAN, an LTE and a GPS antenna. So we have three antennas in a fairly compact design. Do you have any tips on the best way to arrange these within the device, or whether it might be possible to combine several antennas into one antenna?

I hope you can help me.

Thanks in advance!

Curious on how I can better learn the delay characteristics of a signal propagating across a wire. I know there are two factors that contribute to the delay: speed of light flight time and the RC delay. I'm not sure if these delays are purely additive (since the RC delay is basically derived from the elmore's delay of the wire, which is a approximate transmission line model without inductance).

I know certain factors like frequency of the signal, unit RLC, and wire length will all impact the delay, but uncertain how I should go about approximating the delay (at what point is the RC dominated vs at what point is it speed of light dominated)

I 'm currently in my last year of bachelor / integrated master in ece. PHY telecom seems like a very niche field and i wonder what the job market especially for 6g and iot satellite iot is. I ve over invested into it with both rigorous math understanding and hands on experience sdr projects on gnu radio with expensive equipment. Am i wasting my time when it comes to managing to be able to aqcuire a high paying job on that field easily ?

Hi, I see a lot of designs of (basically) SDRs and stuff that use active mixers such as ADL5801/ADL5802/LT5560/etc, and not a lot of modern designs that use single or double balanced diode mixers.

Why is this? I get that the active mixers have gain and diode mixers don't so they would have terrible noise figure if not amplified first, but why not just put an LNA followed by a diode ring mixer?

Edit: For example, Henrik Forsten seems to basically only use active mixers: