Unanswered Questions
722 questions with no upvoted or accepted answers
7
votes
1
answer
1k
views
IIP2 Second Order Intercept Rule of Thumb
I'm faced with the problem of explaining the harmonic production in a system where the second order intercept points of the cascaded components are unknown. As a way to bolster my explanation, I would ...
CommunityBot
- 1
5
votes
0
answers
369
views
How to match an edge launch SMA connector to a pcb with coplanar waveguide with ground?
I'm trying to develop a pcb that is capable of handling signals over 6GHz and created a test board to see how the pcb and connectors perform. The pcb is a relatively low-cost 4-layer FR-4 TG155 board ...
- 123
5
votes
1
answer
308
views
RFID reader array using row/column RF switches (multiplexers)
I need an 8x8 grid of RFID readers arranged on an 8"x8" board. The RFID tags will be placed only millimeters above each antenna.
I was wondering if I could use one 1:8 RF switch (e.g. pSemi PE426482) ...
CommunityBot
- 1
4
votes
0
answers
97
views
Microstrip PCB Design
I am designing a microstrip PCB with frequencies ranging from 100MHz to 8GHz.
There are no significant issues at lower frequencies, but the signal loss becomes quite high as approaching 8GHz.
...
- 71
4
votes
0
answers
78
views
RF circuit/component to generate a chirped waveform (from 0.5 GHz to 1.5 GHz) over 100 ns
I need to generate a 1 GHz bandwidth chirped pulse, 100 ns long. In the past, I have done this using fast arbitrary waveform generators (Keysight M8195A), but this is an expensive and very general ...
- 41
4
votes
1
answer
73
views
Why would a non-nichrome resistive element be desirable?
While working on a circuit design the other day, I happened across a datasheet for a high-frequency resistor that specifically mentions that it uses a "non-nichrome resistive element". In ...
4
votes
0
answers
156
views
High Frequency Oscillations on Mosfet Gate
I am working on a circuit that drives an inductor at its resonant frequency. However certain models of MOSFET I simulate the circuit with experience oscillations at the MOSFET gates as pictured below. ...
- 41
4
votes
0
answers
226
views
bearing ambiguity resolve (direction finding) for multiple sources
I am working on wideband direction finding algorithms for passive sensors.
I started with Music algorithm. For practical reasons, the spacing can not be maintained lambda/2. For greater antenna ...
- 96.8k
4
votes
0
answers
83
views
Is a board with on-board radio disabled an unintentional/intentional radiator?
If a board with the onboard radio (e.g., Bluetooth) chip disabled by software using a jumper, would it be considered to be an intentional or unintentional radiator? That is, the onboard radio can be ...
- 1,557
4
votes
0
answers
175
views
High Frequency Ferrites for Transformers
There are many Ferrite material grades Available.The optimum frequencies start around 20KHz and extend well into the MHz range.There are also many core sizes to go from watts to Kw .Planar cores are ...
- 15.2k
4
votes
0
answers
932
views
Getting the best range with XBee-Pro 900 XSC S3B
I have a pair of 900 XSC S3B xbee pros and a couple 2dBi duck antennas. I just did a simple outdoor range testing and only got about 2,000 feet. I was outdoors without any buildings in the way, but ...
- 243
4
votes
1
answer
322
views
When are 1:1 baluns worth it?
I am trying to build an antenna to connect to the GOES-16 satellite (downlink at 1690,1MHz, linear polarization) with my SDR. My plans are using a 1m offset parabolic dish with a biquad feed connected ...
- 72.5k
3
votes
0
answers
138
views
50 Ohm-Terminated Antenna Oscilloscope Readings
As a follow up to my previous question about measuring antenna performance via amplitude at 88 MHz to 108 MHz on a DSOX1102G oscilloscope, can I trust these new readings? Measurement channel is on 1:1 ...
- 570
3
votes
0
answers
106
views
Unequal resistive power splitter
I'm looking at a 3-port, unequal resistive power splitter design like the dashed-line box in the diagram.
1 is the source, whereas 2 and 3 are two loads of impedance, say Z0. All 1, 2, and 3 are ...
- 131
3
votes
0
answers
155
views
Square vs Round Air-core Inductors for RF filters: When would you use one vs. the other?
The Kyocera AS-series Square Core Inductors boast that "the unique square cross section of the air core inductor provides better performance, and offers manufacturing advantages over toroidal ...
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