# 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.

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### Determine inductance for lossless microstrip transmission line

Given the following parameters: Lossless microstrip transmission line of 50 Ω Capacitance from stripline to ground of 35 pF/m How can I determine the inductance of the line? This is a revision ...
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### Microstrip on FPC board

Do anyone know, what is the strange track on FPC board on image below? My guess is, it is something like a microstrip track. The image is for a FPC board, that measure cell voltage of batteries.
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### Maximum RF power for microstrip

Microstrip line have couple parameters that we can change. It's track width (W), copper thickness (t) & substrate thickness (h). The question is "How much RF power we can transfer by this ...
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1 vote
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### Lumped Element Equivalent Circuit for Microstrip line

I am breaking my head already for 2 days on this problem I have. I want to represent my microstrip line in lumped components. My microstrip line has the following characterstics:  Z_0 = 50 \text{ [\$\...
1 vote
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### Properly grounding an SMA connector (bottom ground plane only)

I’m currently designing my own breakout board for the RFM95W (LoRa module). I’ll be operating at ~900 MHz. The board has two layers. The top layer contains all the signal tracks (no ground pour). The ...
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### Spurious resonance in microstrip transmission line

We were trying to study the broadband response of a microstrip line on a 1.5mm thick Rogers AD1000 substrate whose Dk=10.7 and loss tangent=0.0023 at 10 GHz. The trace width is 1.2 mm. The S21 is ...
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### Name or class of this "square-wave" shaped microstrip antenna

I'm interested in researching/designing a microstrip antenna shaped like this one: But I'm not sure what phrase to type into google. I can see that this is very similar to an inverted-F antenna, but ...
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### Homogeneous magnetic field inside aperture of PCB

I need to create a homogeneous magnetic field of a certain strength across a 10mm diameter opening of a PCB by using a current track on said PCB around the opening. The signal sent through the ...
1 vote
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### How do you combine 3 existing band pass filters to make a triplexer with 50 Ohm ports?

I have designed 3 microstrip band pass filters that each have a good 50 ohm match at the target frequencies (2 m, 70cm and 13cm bands) and I want to combine them into a triplexer to split one signal ...
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1 vote
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### Ground plane for a GSM spring antenna with 4 layer PCB

We are looking to build a 2G GSM based device with a helical spring antenna like this. The work in progress layout is as shown below: We are using a 4 layer PCB with top layer for signal, inner 1 ...
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### Routing ethernet differential pairs over ground plane

I am routing a flexible PCB which connects a panel-mount ethernet connector (without integrated magnetics) to a rigid PCB which contains the ethernet magnetics. I plan to route the differential pairs ...
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### How can I replace lumped capacitor and inductor with microstrip line?

This is a spst switch working on 2.4 GHz. I want to replace the inductor and capacitors with microstrip line. What is the easy way to do that?
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### How do you calculate the power limits and heat dissipation of microstrip filters on a PCB?

We are designing a microstrip diplexer with a high-pass and low-pass filter. What are the power-limiting factors of such a design? The low-pass is a T configuration with two spiral inductors and a ...
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### Via fence distance to the trace?

We have a board design with four layers that uses coplanar waveguide with ground plane: The trace has via fences. Originally, the design was: W=0.35mm, S=0.2mm, and H approximately 0.2mm (for one of ...
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### Matched termination of a microstrip using absorber foam

I have open ended microstrips in an RF circuit (operation freq. 18 GHz) and they cause unwanted back reflection into the rest of the circuit. Now, I wonder if it is possible to eliminate / reduce ...
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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 ...
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### 2.4/5.8 GHz Microstrip Antenna Design

SE, I am trying to replicate the F-shape microstrip antenna design shown in: https://www.researchgate.net/publication/330747527_Dual-Band_Monopole_Antenna_for_RFID_Applications in Keysight's ADS, I ...
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### Best way to connect coax along a microstrip

I have an open-ended (stripped, if needed) coaxial cable that I would like to use to insert a signal into a microstrip. The circuit (operating at ca. 18 GHz) however, is made in a way where I can't ...
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### microstrip patch antenna representation as an array of two slots

from the article bellow we can see the microstrip antenna as an array of two radiating slots which are separated by half a wavelength As shown in the photo bellow.these Electric fields cause magnetic ...
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### Does an increase in frequency affect a capacitors value?

When looking at an open circuited microstrip line, when the frequency is increased the value of the capacitance is changed. When looking at an ideal capacitor the value does not change with increased ...
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### Single Section Branch Line Coupler at 73 GHz

SE, I am having trouble making sense of my simulation charts for a branch-line coupler tuned to 73.5 GHz. I followed Keysight's tutorial given by the link below. https://www.keysight.com/us/en/assets/...
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### Dual sided uFL connections

I am laying out a dual sided PCB, 1.6mm (62mil) thickness. I'm wondering if I can drop a via on the feedline to a uFL connector and place another uFL on the other side. Will this cause unacceptable ...
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### Bad Reflection from SMA Board Connector at 4-8 GHz

recently I have tried to design a simple SMA-to-microstrip connector PCB intended for 4-8 GHz. The connectors used are vertical with surface-mounted centerpin (link). The design idea was to simulate ...
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### Ground plane size of microstrip

I am trying to design an rf mems switch whose conpcept is shown in the image. I am thinking to use microstrip for transmission of signal. Is there any recommendation for minimum width of ground plane ...
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### Coupled Line Bandpass Filter

I am trying to design a microstrip bandpass filter in ADS with a center frequency of 2.4GHz and a fractional BW of 10%. My results from the schematic look great: When I move to the layout and EM ...
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### How to find the distance between two arms of a hairpin resonator?

In this picture I want to find the value of W_cap(the distance between two arms of hairpin resonator). I have the length, width, quality factor and coupling co-efficient of the resonator.
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### I need help with hairpin filter design. Can anyone help me with the design steps and equations? [closed]

I have the coupled line design. But don't know how to convert it to a hairpin structure.
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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 ...
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### What spacing to use between microstrip trace and ground plane on same layer?

I am designing a 4 layer board (1 - signal, 2 - GND, 3 - power, 4 - signal) and I have some microstrip lines on top and bottom layers. Should I fill the top and bottom layer with ground? What do you ...
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I was trying to implement this design in ADS. I have used coupled lines with all the dimensions but didn't get the expected result. Can anyone instruct any better way.
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### How to provide gap between two separate structure or microstrip lines in ADS(Advanced design systems)?

I want to provide gap between two resonators. Here is an image. How do I provide those gap M12 and M23.
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### Feasibility of rat-race as RF mixer without active devices

My understanding is that RF mixers generally use some sort of active device (sometimes diodes) to produce output rich in harmonics, and rat-race couplers can be used to get the sum or difference ...
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I finished the schematic for my 2.4GHz microstrip Wilkinson power divider. I am moving to the layout and trying to do the EM simulation, but I cannot figure out how to put a lumped element in the ...
1 vote
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### Impedance of an embedded microstrip with different sub- and superstrate

I have been trying to find a formula to calculate the impedance of an embedded microstrip where the substrate has a different dielectric constant to the superstrate (so the stack up is conducting ...
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### Microstrip Wilkinson Power Divider

I am trying to design a microstrip Wilkinson power divider in ADS for 2.4GHz. My schematic is shown below: The calculations all check out but I am not getting the best RL at 2.4GHz: If anyone could ...
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### Bias line using Microstrip

I need to bias a transistor amplifier operating between 12-15GHz. I will be using a microstrip bias line to connect DC to the collector as well as the base. I came up with the following simple design ...
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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 ...
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### How do I EM-Extract a subcircuit and define a different em/drawing-layer than the original circuit in AWR?

I have a 4-layer project in AWR/MWOffice and have built a parameterized microstrip inductor schematic (named "spiral") with a "Line Type" of layer1 that I wish to reuse on another ...
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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 ...
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1 vote
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### I have been designing a micro strip patch antenna with inset feed and I have a few HFSS simulation questions

Substrate dielectric: 3.5 Substrate height : 1.5mm Frequency: 2.5GHz I followed a particular video on YouTube to guide me, and used an online calculator for the width and length of patch, inset feed ...
193 views

### Effect of feeder length in microstrip patch antenna

Summary of the question : Why reflection coefficent changes with microstrip feeder line length ? Explanation of the question: I'm working on re-simulating this paper : Microstrip Patch Antenna Array ...
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### Couplers and dividers as baluns

Can every divider and coupler that provides 3dB amplitude divison and 180 degrees phase difference be used as balun? Rat race coupler and lange coupler provide the two conditions mentioned above. ...
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### Antenna range calculation

I'm trying to build a microstrip antenna for my BLE module to increase its range. I'm more of a hardware Design and firmware guy and the last time I designed an antenna was in college back in 2015. ...
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### Microstrip blocking capacitor ground cutout -- large cutout size

I'm attempting to minimize the $S_{11}$ of a $10\,\text{pF}$ DC blocking capacitor on a microstrip trace for my signal frequency range, which is $5.3-5.9\,\text{GHz}$. My microstrip trace width ...
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1 vote
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### Microstrip linear taper effectiveness

I'm trying to optimize the behavior of a DC series blocking capacitor at microwave frequencies (my signal range is from $5.3-5.9\,\text{GHz}$). By optimize I mean keeping $S_{11}$ as low as ...
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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 ...
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250 views

### Non-90deg mitered bends

Is there an approximate equation giving the optimal miter for a non-90degree mitered bend? In particular, I'm trying to determine the correct miter for a 45degree bend. There are a number of resources ...
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### Avoiding microstrip line to become CPWG

I have been designing RF PCBs for a year for an RF front-end system. One of my PCBs has very strict constraints about its size measurements. So, I should design it very densely. The problem with ...
I am trying to calculate the wavelength on microstrip transmission lines. From what I have understand I should use the following relationship: $l = c/(f*\sqrt(Er))$ where Er is the dielectric ...