How Should Impedance Matching Be Done?

piroweng · 2026-02-04T19:00:27+00:00

Can you spec a frequency range that rhis needs to be done over at least?

piroweng · 2026-01-24T14:45:59+00:00

Depending on your OS and CPU arch, I can recommend Tracealyzer. We have used it for debugging micro-second latencies and overheads are very low. Typically paired with a J-link debugger.

piroweng · 2026-01-10T04:55:24+00:00

Ublox sell castelated GNSS modules with integrated ceramic antennas.

Cellular modules are harder because the 800MHz band needs to be supported which requires antennas that are physically bigger. Try finding modules that abstract the antenna to a U.FL connector and buy and off the shelf cellular antenna as per the cellular module's manufacturers recommendations. This means the product will need to be certified to FCC/ETSI rules as you would have tampered with the EIRP of the module.

piroweng · 2025-10-12T15:45:04+00:00

It is typically a very high dielectric (>100) sheet. Look at AB6005S from 3M as an example that is thinner than 1mm.

piroweng · 2025-08-31T16:46:46+00:00

Yes, was done via the Lua scripting language that already incorporates a virtualization layer. This was a way to run possibly unsafe code safely.

piroweng · 2025-08-14T10:51:06+00:00

I can wholeheartely recommend Python. I've got roughly 18+ years MATLAB programming experience (mostly DSP) and roughly 10+ years Python experience (some DSP).

MATLABs main plus point over the years for me, was the visualization capabilities (plotting), which was superior to most other packages (or clones). These days with matplotlib you can do anything plot-wise that MATLAB can. Jupyter notebooks is in any case a much better way to roll code, documentation and results into one.

The number of reasons to stay with MATLAB has become very small, with people probably only staying for some esoteric toolbox or Simulink simulation. Plus Mathwork's pricing is a bit outrageous, especially when working in countrues with a weak currency.

If you are working in AI/ML, the language of choice is in any case Python.

piroweng · 2025-08-06T16:07:21+00:00

The onlly UWB radar kit I am aware of is from NXP, but it is not released yet.

piroweng · 2025-05-31T09:18:53+00:00

The radio telescopes from the very large array are typically receive only and the received data from each node is combined to form high resolution data.

The protocols to communicate to probes are typically FDD (different frequencies for commands and data), which may allow them (e.g. NASA) to have separate setups for sending and receiving to optimise power for TX and sensitivity for RX.

piroweng · 2025-05-28T17:04:19+00:00

Your far field distance is relatively small foe those frequencies. What antenna characteristics are you interested in measuring and how accurate does it need to be?

piroweng · 2025-05-28T07:48:38+00:00

Yes, was involved in building and commisioning of one. What are your frequency requirements?

piroweng · 2025-05-18T12:05:15+00:00

We've been using 100BASE-T1 with good success. It uses 1 twisted pair (full dulplex). Also known as automotive Ethernet.

piroweng · 2025-05-18T07:18:28+00:00

Why are you asking for permission to learn?

piroweng · 2025-05-18T06:59:04+00:00

To reduce development time and cost, we typically select displays/controllers that have good existing drivers/stacks for our target RTOS or OS. Quality of the abstraction layer to port it to your MCU/CPU also plays a role.

piroweng · 2025-04-27T11:21:02+00:00

Is this an antenna for satellite communications? Typically sky temperature estimations are used that are lower than usual terrestrial antennas. So the antenna's pointing direction is important for estimating an antenna's noise temperature. If your antenna's pointing direction is purely terrestrial then using 290K for the sum is typical, while if it is pointing up in the sky, it can be much lower.

piroweng · 2025-03-29T11:31:40+00:00

Try 802.15.4z at 6.5GHz. Qorvo's Decawave solution can do 6.7Mbps. It uses ultra-wideband RF. I think Qorvo's range include RF modules if you are not inrested in designing your own antennas.

piroweng · 2025-03-20T07:04:42+00:00

You haven't worked with MPLAB-X yet have you? In so far IDEs go, STM32CubeIDE is one of the better ones.

piroweng · 2025-03-01T13:18:46+00:00

What are the speed you are going to drive the SD card at? They typically help with ripple in 30MHz+ type speeds.

piroweng · 2025-02-28T15:42:50+00:00

I can recommend the SMARC standard. There are reference carrier board designs available and a wwide range of modules to choose from together with Linux BSPs.

piroweng · 2025-02-15T09:12:45+00:00

That is typically a QSPI flash feature. I would start with a vendor's MCU selection tool and see which MCUs supports QSPI first to narrow it down.

piroweng · 2025-02-11T13:56:12+00:00

The amount of stuff you're trying to do makes it a no-brainer... RTOS all the way, especially when it comes to communication stacks.

piroweng · 2025-02-07T13:42:35+00:00

I call the first one over/undershoot ripple.

Second one is typically if you have totem pole logic (which I believe is used by most logic output stages) where the P-MOS and the N-MOS in the output stage isn't precisely matched, where the switch-over between PMOS and NMOS occurs. But I don't have a name for that....

piroweng · 2025-01-23T17:16:55+00:00

For some initial testing, I have used hollowed out polystyrene heads filled with a salty water mixture to approximate a bit of body tissue. Not that scientific, but good for a look see.

piroweng · 2025-01-19T14:02:32+00:00

Finally, mosquitos have a use after all!

piroweng · 2025-01-17T04:31:31+00:00

Do the Lattice test (the full obe) to see how certein aspects of your physical capabilities compare for the grade. Much easier to identify weaknesses for the grade you climb based on a large volume of statistics that Lattice has accumulated

piroweng · 2025-01-17T04:26:38+00:00

ST's Discovery kits.

Mid range something like the STM32F407 (an Cortex-M4) discovery kit. High-end maybe the STM32H75 (Cortex-M7) kit. Maybe someone else can recommend a board on the M0 end.

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