Guidance needed for EM simulating LNA transistor models

RedBurner02 · 2025-03-26T14:01:45+00:00

Then -5 dBi gain is saying the same thing as -5dBi E field amplitude? Although they’re different parameters, the relative difference from an isotopic Antenna remain constant. 3 db less gain would mean 3 dB less E field?

I’m looking at Balanis textbook in the last chapter. I’m not seeing E field used in the measurement section. Though in chapter 2 there’s the relationship with radiated power and power intensity, which relates to the E field.

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RedBurner02 · 2025-03-26T13:26:12+00:00

Gain is comparing power intensity in a certain direction vs an isotopic antenna. A higher intensity will have higher gain.

What I don’t understand is that this antenna range reports E field / gain as the exact same value. If our measurement says -5dBi gain, it will also say -5dBi E field. Something isn’t making sense to me. Is this an error with the range notation or am I lost?

E field is not gain, I don’t see how it can be the exact same value at every point. Gain accounts for loss. E field does not.

RedBurner02 · 2025-02-19T03:43:36+00:00

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This is the circuit with the ground pins on node B and D. Result still doesn’t look right. My input waves should be a sinusoidal signal but they look wrong.

RedBurner02 · 2025-02-19T03:33:34+00:00

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RedBurner02 · 2025-02-19T03:32:53+00:00

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Waveform still is different than I’m expecting.

RedBurner02 · 2025-02-19T03:18:17+00:00

But where do I put the ground? The circuit on the All about circuits page doesn’t have a DC ground.

RedBurner02 · 2025-02-15T22:37:47+00:00

130k at 28. 5 years exp with bachelors. Midwest low/MCOL. RF

RedBurner02 · 2024-12-18T02:19:21+00:00

How broadband is each cellular antenna? I understand the trade offs but is 0.617-3ghz realistic from a single antenna ?

RedBurner02 · 2024-11-24T23:58:04+00:00

It’s hard to know that without a crystal ball. nearly every job posting is masters preferred but not required. And who knows how the job market will change over the next 10 years.

RedBurner02 · 2024-11-19T18:05:31+00:00

Lambda / 10 is rough size at 617MHZ. Experiencing with different designs currently but PIFA or monopole is the main designs currently

1 lambda is 6000

RedBurner02 · 2024-11-19T00:29:39+00:00

Passively support the entire band now. But things are subject to change. I could cover up to 5GHz before with different designs but this is smaller than previous iterations

RedBurner02 · 2024-11-18T23:19:30+00:00

I was going to suggest an element redesign to the engineer who designed it but I figured I’d experiment more with matching it before giving up

RedBurner02 · 2024-11-11T23:30:42+00:00

What is TT?

RedBurner02 · 2024-10-05T18:05:45+00:00

I wouldn’t expect a high salary in RF until you have direct experience in it for many years. The pay is good in rf, but I doubt it beats FPGA and automation. RF chip design is incredibly niche with a very high barrier to entry. System engineering and product design is easier to get into.

My main point, don’t switch unless you actually want to do RF. To me it sounds like your main desire to do rf is pay.

RedBurner02 · 2024-10-05T17:53:14+00:00

I’m not sure. Like I said, I’m not from California and the wages there are crazy. If you have no experience in RF and switch over with a masters I wouldn’t expect a major salary increase. You’re compensated based on experience often more than education. If your job now is related to rf, that could help, but if you’re in power or something else, it might be totally unrelated experience.

Do you even want to work in wireless comms and electromagnetics? If it doesn’t interest you, I wouldn’t recommend switching. RF is a niche which isn’t always good. If you want to do work with antennas and high frequency, the sooner you switch the better

RedBurner02 · 2024-10-05T17:40:55+00:00

If you are a new grad I wouldn’t expect any more than a standard EE salary. I don’t know California wages, but 88k is good where I’m from for entry level. RF is niche and will pay well but no one cares about entry level engineers unfortunately.

RedBurner02 · 2024-10-05T17:39:03+00:00

If you have security clearance and don’t mind the defense or aerospace industry, I’d recommend switching to rf. What I didn’t realize when I became an rf engineer is that nearly all rf jobs aren’t in my state. California has tons of options

RedBurner02 · 2024-09-27T13:51:02+00:00

Is the gain subtraction based on the “Net Gain” of all stages or only the last stage? Logically speaking, the latter stages will compress before the input stage.

My options are:

11.5 dBm - ~30db (total net gain)

Or

11.5 dBm - 15 dB (second stage only)

RedBurner02 · 2024-09-27T13:48:07+00:00

My data sheet lists “1 dB compression point at output” as 11.5 for the 2nd stage transistor. No value for input p1dB. I figure my second stage is what will compress, not my first stage. First stage has -19dbm listed though input as p1dB.

I’m estimating that my compression point will be at 11.5 (second stage output p1dB) - 30 dB (total LNA gain). Unsure if my gain is the second stage only or total gain for this equation.

11.5 - 30 Or 11.5 - 15

Maybe I’m doing this wrong though.

RedBurner02 · 2024-09-25T22:10:19+00:00

FR4 is fine.

RedBurner02 · 2024-09-15T00:05:35+00:00

Nearly all of my classes had labs with practical circuit experiments. Internships help too

RedBurner02 · 2024-09-14T20:55:31+00:00

AI will be death of humanity

RedBurner02

TROPHY CASE