https://forum.microwaves101.com/categories/13/general-questions/feed.rss Wed, 15 Jul 2026 20:02:14 Z General Questions - Microwaves 101 Discussion Board en https://forum.microwaves101.com/discussion/234/broadband-load-on-printed-circuit-board Sun, 15 Mar 2026 20:14:40 Z UnknownEditor 234@/discussions Anyone care to contribute their favorite trick for getting a fifty ohm load to behave on a circuit board, say, from DC t0 40 GHz? Looking at ways to improve just a fifty ohm resistor grounded through a via hole with catch pad. Could be stripline or microstrip, I am just curious how you compensate... https://forum.microwaves101.com/discussion/229/multi-carrier-signal-back-off Sat, 27 Dec 2025 01:31:27 Z UnknownEditor 229@/discussions Is there some estimation about how much to back off output power when amplifying a multi-carrier signal? Asking for a friend... Steve https://forum.microwaves101.com/discussion/240/looking-for-60-year-old-germanium-transistors Sun, 12 Oct 2025 20:14:10 Z UnknownEditor 240@/discussions I have a Super Vox Continental from 1967, the two-keyboard version of this: https://www.youtube.com/watch?v=ILtgCDot5kU The active components are all germanium PNP transistors, here is the part number NTE102A We have replaced quite a few, but need more. Does anyone have any idea where to buy some... https://forum.microwaves101.com/discussion/228/text-book-survey Wed, 06 Nov 2024 23:54:25 Z UnknownEditor 228@/discussions Does anyone buy text books these days? Do you buy paper books, or e-books? How many microwave books do you have on your shelf? Do you buy books at a discount at trade shows, or just buy them on-line? What do you think the future of technical books (and websites) will be now that AI is becoming a... https://forum.microwaves101.com/discussion/224/measure-noise-figure-of-something-with-really-low-noise Sat, 28 Sep 2024 13:50:54 Z UnknownEditor 224@/discussions Say you had a really nice LNA with 1 dB noise figure expected but you were measuring 1.5 dB. What are the sources of errors? Reflection coefficient of the LNA (which is not good)? Could some low-level bias line oscillation ruin the data? Which is better, PNA with NF option or spectrum analyzer... https://forum.microwaves101.com/discussion/220/micrrowaves101mtt-s-ims-special-session Fri, 02 Aug 2024 23:38:46 Z UnknownEditor 220@/discussions We are discussing holding a special session on Microwaves101 at the 2024 IMS conference. This is still in development, topics might include 1. Some perspective on the site from the Unknown Editor 2. IMS committee comments on collaborations, which will focus on getting people to contribute content... https://forum.microwaves101.com/discussion/222/ask-mtt Sun, 24 Mar 2024 22:06:01 Z UnknownEditor 222@/discussions This is a new resource from IEEE MTT-S, accessed through LinkedIn https://www.linkedin.com/groups/8161702/ They went from 0 to >500 members in a short amount of time. My understanding is that questions will first go through a screening process, to eliminate inquiries about design details, possible... https://forum.microwaves101.com/discussion/214/reactive-power-combiners Sat, 23 Mar 2024 18:55:13 Z UnknownEditor 214@/discussions Suppose you are designing an SSPA by combining four GaN MMIC amplifiers. You are considering a reactive power combiner... if the amplifiers behave the same in phase and amplitude, they will see the same impedance match that the power combiner output provides (generally quite good). If a single... https://forum.microwaves101.com/discussion/219/anyone-recognize-the-marking-here Wed, 14 Feb 2024 01:46:13 Z rfdave 219@/discussions Does anyone recognize the vendor on this part? It's a final drive stage in a 30-40 W PA I've got? Looking for a datasheet if possible. (How can I get the image to show up? It's on dropbox now) https://forum.microwaves101.com/discussion/218/phase-shifters-and-tdus Sun, 14 Jan 2024 19:43:50 Z UnknownEditor 218@/discussions In future AESA designs, with the advent of digital signal processing reaching microwave frequencies, does anyone think that analog phase shifter and TDU designs are going the way of the buggy whip? Maybe phase shifters move from GaAs to silicon and stops there and stays analog. Digital phased... https://forum.microwaves101.com/discussion/216/are-signal-flow-graphs-used-much-anymore Sun, 07 Jan 2024 17:42:20 Z Michael Maassel 216@/discussions Good day. I had a student ask me about signal flow graphs and if they are still being used. I could not give him an answer since I have not seen them used for a few years. I just wanted to check with a broader field of people to see if Signal Flow Graphs are still useful and still being used. Thank... https://forum.microwaves101.com/discussion/215/ieee-mtt-s-and-microwaves101 Thu, 16 Nov 2023 14:41:29 Z UnknownEditor 215@/discussions We once had a partnership with MTT-S. Lots of people worked for several years trying to make this work, but it fell apart for a few reasons... 1. MTT-S paid for someone to redesign and host the site but left us hanging with limited editorial access, quite a few back-end bugs, and considerable... https://forum.microwaves101.com/discussion/200/supply-chain-issues Sat, 05 Nov 2022 00:05:29 Z UnknownEditor 200@/discussions Just looking for any horror stories about recent supply chain issues .... I have seen problems with resistors, capacitors, diodes, RFICs, connectors, housings... what supplier thinks 52 weeks delivery time is gonna land a future order? Maybe we should work with a Tarot card reader to assess the... https://forum.microwaves101.com/discussion/197/active-bias-used-in-radio Mon, 05 Sep 2022 20:52:32 Z UnknownEditor 197@/discussions Hello out there... we could use some content on active bias networks, for GaN and GaAs amplifiers. While on the subject, here's a question... if you were designing a power amplifier that is modulated all over the place in terms of power, such as 64-QAM, and you use an active bias network to hold... https://forum.microwaves101.com/discussion/190/gpr-using-high-isolation-duplexor-using-a-circulator-and-pin-diode-switch Fri, 20 May 2022 18:29:15 Z Norman grody 190@/discussions After completing my radiometer book I started a new project constructing low power Ground Penetrating Radars (GPR's) at 4 and 12 GHz. The transmitters are simple Dielectric Resonant Oscillators (DRO's) that generate only about 5 milliwatt's of CW power. The DRO is pulsed every microsecond using a... https://forum.microwaves101.com/discussion/186/revenue-cycle-management-solution-for-a-clinic Sat, 02 Apr 2022 21:25:10 Z Soni0812 186@/discussions I have been looking for Revenue Cycle Management Solution for my Clinic. Can someone suggest a few companies in the USA that can help me make my cash flow procedure faster? https://forum.microwaves101.com/discussion/178/passive-tripler Fri, 25 Feb 2022 15:52:52 Z UnknownEditor 178@/discussions Does anyone have any information on designing a passive tripler? Looking for an output north of Ka-band.... Thanks in advance Steve https://forum.microwaves101.com/discussion/182/balun-combined-amplifiers Fri, 25 Feb 2022 15:50:07 Z UnknownEditor 182@/discussions Just wondering what kind of trouble could lie ahead when combining MMIC power amplifiers with external baluns. A low-loss balun has poor isolation... could this cause an oscillation? would it be a transient thing on startup and then die down or could it oscillate all the time? Does it matter that... https://forum.microwaves101.com/discussion/180/harmonics-in-solid-state-switches Sat, 08 Jan 2022 20:19:04 Z UnknownEditor 180@/discussions Does anyone have an experience with PIN diode or other solid-state switches where a signal is being passed at, say, 2 GHz and it generates harmonic spurs at 4, 6,... 8 GHz? There must be some harmonic content when you hit the compression point, right? But what about 10 or 20 dB below compression?... https://forum.microwaves101.com/discussion/170/wilkinson-resistor-test Sat, 09 Oct 2021 18:08:18 Z UnknownEditor 170@/discussions We've all used Wilkinson power dividers... the network shorts out the resistor. So how do you know the resistor value is within specified tolerance? OK, maybe the tolerance could be +/-10%, so it would be hard to screw up a thin-film job. Or maybe you are attaching 0402 (or even 0201) resistors to...