Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [microstrip]

A microstrip is a transmission line fabricated on a printed circuit board (PCB). They are much less expensive than a traditional waveguide although they typically have higher losses and less power handling capacity.

129 questions
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Microstrip through passive components

I am a bit confused with the implementation of a microstrip line to an u.FL connector. In order to maintain a 50Ohm line, the trace width would need to be ~0.1 inches wide, I have a pi matching network for 'just in case' implemented in line with the…
MadHatter
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What is Negative Inductance?

I am experimenting with a stripline square spiral inductor in Sonnet and the graph is showing both a positive and negative inductance. What does it mean to have a negative inductance? Why does it swing above and below 0? What does it mean about the…
KJ7LNW
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USB trace impedance calculations, with termination resistors

I'm designing a PCB featuring a Renesas RZ-A1 microcontroller, and want to check that I'm doing my USB D+ and D- traces correctly. This application note from Fairchild (alternative link), which is one of the top Google results, says that D+ and D-…
beammy
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What is wrong with my 50Ω microstrip?

I'm currently working on a 6 layer board that has both an applications processor and a GNSS module (along other things), and I find myself in a certainly puzzling situation. Let me describe: I have a 6 layer board manufactured by JLCPCB, with prepeg…
Aleix
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How to calculate signal propagation speed through vias?

There is a need to have a group of signals arrive simultaneously to their respective destinations, given that they start their journey at the same time. However, due to physical constraints it is not possible to have them routed on the same layer,…
user3812
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Microstrip over power plane

I am designing a 4-layer PCB with 16 channels of LVDS (differential signalling, 480MHz). My layer stackup is Signal-GND-Power-Signal. A microstrip design for the LVDS channels is usually traces over a ground plane. However, I was wondering if it was…
cksa361
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RF Ground Stitching in Proteus Ares 8

I am using Proteus Ares 8 to create a PCB for a simple RF circuit. I have a double sided copper board, filled with groundplane on both sides, with a single 50 Ohm microstripline across the board to two SMA sockets, just as an example: What I am…
M1GEO
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How can I guarantee 50 ohm impedance on PCB trace?

I have a question. Imagine that I need to have a 50 ohms impedance in a PCB trace. For simple cases it's just applying the formula found all over the internet or use one of the online calculators While looking for this information online I came…
morcillo
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Matching RF traces

The datasheet for this part states the input and output are internally matched to 50 ohms. However what exactly does this mean? For example the output, would I still need a 50 ohm microstrip to connect the output to a SMA connector? Could this…
Mike
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Why is there a solder mask opening over a microstrip line?

I have always wondered why there is an opening in the solder mask whenever a microstrip line is laid out on a PCB. For reference consider the following board: There is clearly a large opening in the board around the microstrip lines and stubs. Does…
hacker804
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Can differential USB traces be routed relative to Power (not Ground) planes?

I would like to route my USB 2.0 (12MHz) signal on the bottom layer of a 4-layer PCB. However, the edge-coupled microstrips would then be referenced to the power plane, not the ground plane. The signals are going to the USB pins of an STM32F105…
bitsmack
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Consensus on microstrip trace impedance calculations?

I'm designing a PCB that has a 2.4GHz signal that I'm routing to an SMA jack. I'm trying to figure out the geometry of the necessary microstrip trace. This is the first rf PCB I've worked on. The problem is that if I feed the values into different…
bitsmack
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Qucs simulation of quarter wave microstrip stub doesn't match ideal calculaton

I'm trying to simulate the resonant frequency and insertion loss of a 3 mm open stub on a 10 mm microstrip transmission line (50 Ω) on a FR-4 PCB (εr = 4.0, height = 0.1 mm). I calculated that the microstrip width should be around 0.188…
比尔盖子
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2.6 GHz microstrip patch antenna with 100 MHz bandwidth

I'm trying to design a microstrip patch antenna @ 2.6 GHz. The result I got is good but the antenna is very selective and I haven't been able to increase the BW. Currently, the BW is 40 MHz and I need it to be 100 MHz (S11 = -10 dB @ 2.55 GHz //**//…
teleco
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How to route a trace on PCB with 50 Ohm impedance?

I used some online calculator to calculate parameters of trace so it has 50 Ohm impedance. I use FR-4, so H=1.5mm, T=0.035mm and Er = 4.5. 2-side PCB, one side with signals, the other with GND. I set the calculator to "microstrip" and for this data…
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