This configuration of the CPW is known as the conductor-backed coplanar waveguide. Coplanar Waveguide Calculator. Microstrip lines, coplanar waveguides. Coplanar Waveguide Calculator. Choose a routing style (microstrip, stripline, coplanar waveguide, single-ended vs differential) Calculate the trace width needed to give the required impedance; After everything is routed, it’s now a question of whether it’s appropriate to fill in the unused regions of the surface and internal layers with the grounded copper pour. Apply the Havel-Hakimi algorithm by iteratively performing the following steps: a. The line has a conductor resistivity and a tangential loss factor. This chapter presents the characteristics of a coplanar waveguide with a lower ground plane. Width (W) in micrometers: Gap (G) in micrometers: Height (H) in micrometers: Substrate Height (Hs) in micrometers: Calculate. 0 of permitivity) at. Enter values for R1 and R2 to calculate attenuator loss and impedance. The modeling of differential coplanar waveguide is similar to that of single ended waveguide as shown in Figure 4 d. The formulas to. A grounded coplanar waveguide (GCPW), as a millimeter wave special transmission line, can be used to calibrate broadband oscilloscope probes. generally the top of a dielectric substrate. A differential stripline pair refers to two traces located between two reference plane layers, which are routed as a differential pair. Ω. This free online calculator help you to check the vectors coplanarity. All of this includes contributions from coupling. and the conductor thickness is thinner than 0. Ramo, J. MAX2605EVKIT. There are some advantages to using a microstrip transmission line over other alternatives. More importantly, it can provide extremely high frequency response (100 GHz or more) since connecting to CPW does not entail any parasitic discontinuities in the ground plane. e. In effect, the role of a differential pair impedance calculator is to calculate one of the odd-mode or differential impedances, and then use this to calculate the other while assuming the two ends of the pair obey specific geometries. Odd-mode impedance defined in terms of differential impedance. Alternatively, Generate R1 and R2 for a wanted attenuation. 3. Guide. Stripline Impedance Calculator. 1. A single-ended microstrip line has only constraints for. 2. 45 for gold. The PCB Impedance Calculator in Altium Designer. Coplanar GB waveguide calculator C-Coupled Resonator designer---- Butterworth Prototype---- Chebyshev Prototype Coax Impedance calculator Chip Resistor De-rating calculator dBm/Linear power converter. Some example broadband signal integrity metrics are:. Coplanar waveguide with stitching vias. 75 mm track on a 0. When in doubt, use 1 for copper, . 1 © 2016 ANSYS, Inc. Otherwise, find a "coplanar waveguide" calculator as it'll compensate for the nearby ground plane. In this paper, the methods used to analyze FGC, FGC waveguide propagation characteristics, and how FGC may be. They are also used on single-layer boards that lack a ground plane. Thus a "differential pair" any long distance apart will have an impedance of 98 ohms, without any coupling between the lines, i. If you’re designing an RF PCB. If you recall my earlier article on microstrip vs. Our free impedance calculator for coplanar waveguide can help you with your design features to ensure your PCB is working as you intend. Flat Wire Inductor For a flat wire, ribbon or PCB track, showing the formula used. From here, we can see that there are specific stackups where a CPW and a microstrip/stripline will have 50 Ohm impedance and the same trace width, even though the ground clearance is quite close to the trace in the CPW. The edge couple differential microstrip transmission line is a common technique for routing differential traces. A waveguide is a transmission line that contains microwave signals inside a hollow tube and prevents them from radiating outward. You can use an online coplanar waveguide calculator to play around with your design. Added calculation for Electrical Length as Air Line equivalent; Added calculation for Delay time ;. In fact, striplines often make components such as band-pass filter's more accurately, with more symmetric roll-off and no lower cutoff frequency. 4 Conventional Coplanar Waveguide on a Finite Thickness Dielectric Substrate and with a Top Metal Cover 21 2. Each tool is written in Javascript and the user can view the page source should they wish to examine the. I've calculated the characteristic impedance of a CoPlanar Wave Guide (CPWG) type transmission line on my 8-layer stack-up between L1 - top layer and L2 - GND1 directly underneath it. )May Need to Strap Grounds together on Either Side of Trace, every 1/20th Wavelength. Thread starter tennythomas; Start date Aug 30, 2010; Status Not open for further replies. Grounded Differential Coplanar Waveguide Calculator. Don’t forget to check out our other. Radio Frequency Engineering Calculator. Can anyone provide Grounded Differential Coplanar Waveguide calculator? Thanks in advance. 3. 5mm pitch flat flex as differential coplanar waveguide for routing 1000Base-T ethernet, and I'm using a single ground trace between the differential pairs, sketch attached. Relative Dielectric Constant ( εr ): Track Width: mm. The via spacing is to create a virtual wall the the RF energy. This calculator determines the impedance of a symmetric differential stripline pair. R. If you’re designing an RF PCB for microwave or higher frequencies. This transition consists of a differential line inserted from the narrow wall of. Grounded Differential Coplanar Waveguide calculator. (This image shows CPW with a ground plane, but you can have CPW on a single-layer board) As a rule of thumb, for standard 50-Ohm microstrip, the trace width ( w) is approximately twice the. From here, we can see that there are specific stackups where a CPW and a microstrip/stripline will have 50 Ohm impedance and the same trace width, even though the ground clearance is quite close to the trace in the CPW. For design purposes, a theoretical transmission-line model for the coupler is established, which is based on the characteristic parameters of the related coupled CPW structures. However, both the top an bottom are flooded with ground plane as shown. Grounded Differential Coplanar Wave Guide. 9: Differential coplanar. Choose a routing style (microstrip, stripline, coplanar waveguide, single-ended vs differential) Calculate the trace width needed to give the required impedance; After everything is routed, it’s now a question of whether it’s appropriate to fill in the unused regions of the surface and internal layers with the grounded copper pour. Figure 8a. V-shaped conductor backed coplanar waveguide (VGCPW). 29mm, space between trace and top ground is also 0. Just like differential microstrips, two central strips are routed alongside each other on the surface layer and are driven with opposite polarity. This metal layer is typically connected with vias to the metal layers above the dielectric. Coplanar waveguides are open quasi-TEM waveguide geometries that use copper pour and a ground plane to provide shielding along the length of a PCB trace. The standard coplanar waveguide can be placed above a ground plane, or it can be placed without ground (i. Rs =. The image below shows a typical coplanar waveguide with ground. Design. Spacing and width value pairs that will give a differential impedance of 100 Ohms on Dk = 4. If you. - Dk = ɛ-jɛ’, where: ɛ = energy stored, and ɛ’ = energy lost. Coplanar Waveguide Calculator. Posted August 19, 2020. Embedded microstrips are commonly crafted using printed circuit boards, although other. To answer, Zac. TX-LINE software is a FREE and interactive transmission-line utility for the analysis and synthesis of transmission-line structures that can be used directly in Cadence ® AWR ® Microwave Office ® software for matching-circuits, couplers, and other high-frequency designs. Mixer Spurious Product Calculator. 45 for gold. The edge couple differential symmetric stripline transmission line is a common technique for routing differential traces. In this example, the impedance a coplanar conductor-backed waveguide is calculated using the FDE solver’s Power and Impedance Integration tool, and the result is compared with the approximate analytic result from an online impedance calculator [1]. Therefore, dx and dy in real space scale into Mdx (= du) and Mdy (= dv) respectively in the mapped. 81. The ultrawideband design approach is based on the excitation of a coplanar waveguide (CPW) mode and a coupled slot line (CSL) mode in the same double slotted planar waveguide. 3 Conventional Coplanar Waveguide on a Dielectric Substrate of Finite Thickness 20 2. The advantages of coplanar waveguide are that active devices can be mounted on top of the circuit, like on microstrip. g. Coplanar Waveguide Analysis/Synthesis Calculator. A Coplanar waveguide is a common type of transmission line used in any PCB implementation of RF and microwave components. If there is something in the microwave universe that you need a different calculator for, drop us a note and we'll see what we can do to include it here. 5 resin). 1 Conformal Mapping and Partial Differential Equations A point in the w-plane can be related to a given point in the z-plane with a func-tion. Don't need to leave clearance, just calculate it for the appropriate trace impedance. The length tuning interface for differential microstrip pairs in Altium Designer. Users need only specify the material properties for. The backside of the strip can be made of air or metal (grounded coplanar waveguide). 2. You will likely need to use an EM simulator if you want to account for ground pours near the signal traces. The STLC online tool enables the user to precisely calculate the wave impedance of all commonly used transmission line types on PCBs by applying a powerful 2-D field solver technology. In this design there is a coplanar ground plane a controlled distance away from the trace that is close enough that it significantly affects the impedance of the trace. A novel edge-coupled coplanar-waveguide (CPW) directional coupler with a floating backed conductor is proposed. <P>The coplanar stripline (CPS) consists of a dielectric substrate with two parallel strip conductors separated by a narrow gap. LineCalc was used to calculate the length and width for a quarter wave transformer. List of our impedance calculators Following is the table of 82 impedance calculators that are designed and categorized based on the different trace geometries: To use this calculator, simply input your microstrip geometry and Dk value, and the tool will return the differential impedance value for a pair of microstrip traces. When in doubt, use 1 for copper, . Whinnery and T. PCB Coplanar Waveguide Calculator RF PCBs can be complex boards that need careful interconnect design and layout. try port width 3 (2g+w) and height 4h, where g is the gap between conductor and side ground, w is the width of conductor, h is the height of substrate. Differential pairs should be tightly coupled throughout their entire length, so try to avoid variations due to pads, vias, or components along the routing path. Characteristic. calculate the surface impedance instead of using scaled surface impedance. Applies to Transverse ElectroMagnetic propagation. The characteristic impedance (Z o) of coplanar waveguide with ground or microstrip lines with signal side ground plane can be calculated using the active calculator or the equations at the bottom of. the structure without a lower ground plane) and set the ground strip separation dimension, D1, so it is 20 x that of the Trace Separation dimension, S1. TX-LINE software enables users to enter either physical or electrical characteristics for common transmission mediums: microstrip, stripline, coplanar. *The structure may propagate in 3 modes: coplanar waveguide, coupled slot lines and microstrip. BrandCoplanar waveguide. In cst, when I simulate my structure, it calculates the s-parameters by considering the input impedance if the exciting waveguide port. GCPW achieves an extra level of grounding and isolation by fabricating a. The microstrip calculator determines the width and length of a microstrip line for a given characteristic impedance (Zo) and electrical length or vice versa. What is coplanar waveguide. 9: Differential coplanar. Figure 1 - 3D model of the transition from microstrip line to CPW (a) top view of the model, (b) bottom view of the model. 2. nm um mm cm m mil inch. Solve Now. Either the desired impedance at a specific frequency is used to determine the waveguide width, or the width is entered and the impedance is calculated. Cohn). Edit: The following image shows the differences between the coplanar and microstrip transmission lines. 5 mm. This calculator requires symmetry in the trace widths and location between plane layers. To download this add-on:. Use the coplanarWaveguide object to create a coplanar waveguide transmission line. It is always better to use the top layer for the coplanar waveguide and the second layer for ground. Radio Frequency Engineering Calculator. If you run ground pour right next to the analog traces, you’ve just created a coplanar waveguide, which has high isolation and is a common choice for routing high-frequency analog signals. Coplanar waveguide vs stripline. , in u-v plane), where M(u,v) is defined as in eqn. Create your website today. The same is true to calculate common to differential mode conversion. Thickness: Thickness of the microstrip conductor. Fast Coplanar Waveguide analysis of five of the most popular microstrip structures. Single and differential coplanar structures; Multiple adjacent dielectric layers, with different dielectric properties. b. Vilcins-Czvitkovits, D. For this case the capacitance per unit length of the line is given by analytic results [1] C(cp,a)/L =4ǫK(κ)/K(p 1−κ2) (11) ≃ (4ǫ/π)ln[2(1+ √ κ. b. COMPARISON WITH COPLANAR LINES This theory may be tested against analytic results for the geometry of a coplanar waveguide with centered width w and separation s, as illustrated in Fig. Calculating the Differential impedance is a two-step process, first Calculate the single ended impedance Zo and then use this value to calculate the differential. download the Integro-Differential Modeling Framework for MATLAB. Width (W) in micrometers: Gap (G) in micrometers: Height (H) in micrometers: Substrate Height (Hs). < 0. Microstrips and striplines also come in the coplanar and differential varieties, and all of these have certain advantages when used for high-speed or high-frequency signals. A coplanar waveguide transmission line is defined in terms of width, spacing, and thickness on a given relative permittivity substrate of a certain height. Electro-optic modulators (EOMs) based on a thin-film lithium niobate (TFLN) photonic integration platform play a crucial role in loading electrical signals onto optical signals. I read it. 2021 — Online Calculator . 如何利用Q2D計算共面差分帶對的差分阻抗視頻顯示了使用Q2D計算共面差分帶對的流程The video shows the flow to calculate coplanar. The coplanar option designs a grounded coplanar waveguide structure. 11. This voltage difference is applied through the multielement uniform type of a lumped port that equally divides the signal between two ground planes. The Si8000m adds enhanced modelling to predict the finished impedance of multiple dielectric PCB builds and also takes into account the local variations in dielectric constant on close spaced differential structures. conductor backed coplanar waveguide (CB-CPW) [2]. *Solder resist PCB coating will have the effect of lowering the impedance (due to the 30um or so of Er 3. 6 2009/02/11 00:00:28 dan Exp $ Development Kits. 1. from publication: Accurate study of the electromagnetic and circuit. By the way, waveguide is technically NOT a transmission line, but it serves the same purpose. This limi- tation has become increasingly important with the proliferation of miniature, integrated-circuit wave-Equivalent circuit analysis. The calculator below uses Wadell’s. You can specify multiple name-value pairs. Edge Coupled Stripline Differential Impedance Calculator. A grounded coplanar waveguide is a modified version of FB CBCPWs, in which the coplanar side grounds are connected to the lower ground planes using vias. *The structure may propagate in 3 modes: coplanar waveguide, coupled slot lines and microstrip. Differential Amplifier; Inverting Amplifier; Inverting Comparator with Hysteresis • Schmitt-Trigger;. Calculator. cpw ('ConductorWidth',0. If you can simulate or calculate the S-parameters. There is a closed-form solution for the two-dimensional stripline problem, that is, for infinitely long coplanar strips. Flat Wire Inductor For a flat wire, ribbon or PCB track, showing the formula used. 13 HFSS Wave ports are used for: •Closed structures like waveguides and coaxial cables • multiple propagation modes •Surfaces exposed to background object •Structures with uniform waveguide or transmission line where the port attachesTransmission Lines – Microstrip, Coplanar, and Coax. Edit: The following image shows the differences between the coplanar and microstrip transmission lines. A coplanar line is a structure in which all the conductors supporting wave propagation are located on the same plane, i. PCB Coplanar Waveguide Calculator RF PCBs can be complex boards that need careful interconnect design and layout. All transmission line structures, such as microstrip, stripline, or CPW. Overview. For a coplanar waveguide, the width required for 50 Ohms impedance on the same substrate is ~20 mils. cifomibeq's Ownd. ”. The. The capacitance calculated using this tool is the capacitance between two coplanar flat conductors. This new transmission line is called Finite Ground Coplanar (FGC) waveguide and is illustrated in Figure 1c. Height: Height of the substrate. A method to change the through-hole structure to widen the GCPW is investigated in this paper. 1. 3) creates an RF coplanar waveguide transmission line with a width of 0. Grounded Coplanar Wave Guide. But the choice of transmission-line technology, such as microstrip or grounded coplanar waveguide. GEGCalculators. **Note: Like our stripline impedance calculator, all of our RF calculators allow SI prefix input. To avoid microstrip modes, have h >> (w+2g) and extend component side ground away from the trace by > (w+2g). What is the effective dielectric constant of a coplanar waveguide? The effective dielectric constant of a CPW depends on the geometry and materials used but is typically in the range of 2 to 5. Solve Now. The coplanar waveguide (CPW), coplanar stripline (CPS), and the slot line are uniplanar transmission lines with all conductors, the signal and ground conductors, on one side of the substrate. 2. This parameter is used for the loss calculations. FleetRF Pvt Ltd. The calculator below automates this for you, giving you the odd-mode impedance for a single trace and the differential impedance for the pair. the structure without a lower ground plane) and set the ground strip separation dimension, D1, so it is 20 x that of the Trace Separation dimension, S1. The return loss in this paper is 20 dB, which is 10 dB higher than the full-wave 3D simulation experiment of transmission line carried out by Peerouz Amleshi . 2020 — Apply the values to the differential calculation, e. If you’re designing an RF PCB for microwave or higher frequencies. The line has a conductor resistivity and a tangential loss factor. html,v 1. Thickness: Thickness of the stripline conductor. GROUNDED COPLANAR WAVEGUIDE TRANSMISSION LINES AS PICKUPS FOR BEAM POSITION MONITORING IN PARTICLE ACCELERATORS A. Adjustments in lens design and materials can help manage its influence. Instructions are below the calculator and don’t forget we can make and test your controlled impedance printed circuit boards too. Coplanar waveguide (CPW) (Figure (PageIndex{1})(b)) [1] supports a quasi-TEM mode of propagation with the active metallization and the ground planes on the same side of the substrate. This class is highly inspired by the. When you want to determine the width and length of a microstrip line for any given characteristic impedance and electrical length, or vice versa, a microstrip calculator is the right tool to do so. Do math problem. The microstrip is a very simple yet useful way to create a transmission line with a PCB. Properties not specified retain their default values. There is no one size fits all, but using a 5 thou to 6 thou track width as a starting point helps narrow things down. The calculations are pretty standard and supported by many freely available calculators. Step 2: In the second optimization step, the coplanar gap was held fixed at 5. These aren't very common, but I think the Saturn PCB toolkit does it? Saturn doesn't have it. Figure 1: Antenna input trace. TX-LINE software is a free and easy-to-use Windows-based interactive transmission line calculator for the analysis and synthesis of transmission line structures. Learn how to model structures that are not included in the Si8000m and Si9000e calculators, such as semi-coplanar, offset coplanar strips, and differential surface coplanar waveguide. 1524mm (I've used this for the differential. structures is addressed in this Letter. There are four different types of impedance used in characterizing differential trace impedances. 2 < < 10. Coax loss will be about 10X higher (in dB). This calculator is designed to calculate the characteristic impedance of an edge-coupled microstrip. 9. For example, a single 0. MMCONV Visualization. Slotline. The same limitations for S and G apply in this topology as for the grounded coplanar. (This image shows CPW with a ground plane, but you can have CPW on a single-layer board) As a rule of thumb, for standard 50-Ohm microstrip, the trace width ( w) is approximately twice the. Single Ended Impedance Ω. After each subtraction, re-sort the sequence in non-increasing. This parameter is used for the loss calculations. The coplanar waveguide (CPW), coplanar stripline (CPS), and the slot line are uniplanar transmission lines with all conductors, the signal and ground conductors, on one side of the substrate. Although its not shown since I haven't done the copper pour yet (or the via fence), these tx lines are grounded coplanar waveguides with width 0. Coplanar Waveguide formula: ? TransCalc is an open-source impedance calculator of various transmission lines based on common closed-form approximations. 3 Conventional Coplanar Waveguide on a Dielectric Substrate of Finite Thickness 20 2. There are four different types of impedance used in characterizing differential trace impedances. So, the results are normalized on this reference impedance. Cadence/AWR. e. The grounded differential coplanar wave guide is the differential version of the grounded coplanar wave guide and is used in high-speed digital systems that require maximum noise immunity. Enter the relative permitivity, width of the trace, the ground plane spacing, and the substrate thickness to calculate the characteristic. download the Integro-Differential Modeling Framework for MATLAB. Cohn). Note that the y-axis is on a logarithmic scale for clarity. Optical modulator length should be changed only if the effective phase shift length changed (doped length). GCPW S-Parameters and Digital Signals. Differential coplanar waveguide with ground light sensor wiring harness Radar systems, wireless systems, high frequency analog systems…all of these need to include measures to ensure signal integrity. PCB Coplanar Waveguide Calculator RF PCBs can be complex boards that need careful interconnect design and layout. Transmission-Line Calculator. This is common in semiconductors where it is difficult to access a ground plane and the distances are very short. Ramo, J. See how in your microstrip example the traces are 192 um wide while in the coplanar design they are 117 um wide. Differential Coplanar Waveguide; Differential. but it's probably the fastest solution. Edge Coupled Stripline Differential Impedance Calculator. i know that i can use. However, convention and some literature quote return loss as a negative value akin to an S (1,1) measurement on a Network. Grounded Differential Coplanar Wave Guide. The JLCPCB Impedance Calculator computes track width values and recommended stack-ups from user-input values of board layer, thickness, copper weight, target impedance, trace spacing (for edge-coupled pairs), and impedance trace to copper gap (coplanar waveguides). One routing structure, called a substrate integrated waveguide, provides a useful alternative that is ideal for engineering the electromagnetic field along an. . The grounded coplanar waveguide (and its variants) is probably the most well-known interconnect structure among RF engineers that work with microwave frequencies. We offer an affordable online solution to calculate the line impedance on printed circuit boards (PCB). Conductors are assumed to have zero thickness. The lower ground can be used for heat sinking purposes while providing mechanical support and preventing the fields from coupling to interconnects on lower circuit layers [3], [4]. HomeMicrostrip Impedance Calculator. Round Coaxial Cable Calculator. This chapter discusses CPS and its variants, including asymmetric CPS (ACPS), the CPS with an infinitely wide ground plane (CPSWG), and the CPS with. If you’re designing an RF PCB for microwave or higher frequencies, controlled. 2. 946 for silver, or 1. The substrate has a relative permittivity of 9. coplanar waveguide coupling into, and out of, the device. The differences between the two structures can be seen in the illustration below. This way the adjacent coplanar grounds will be far enough away to have negligible influence. Coplanar Waveguide Analysis/Synthesis Calculator. This function converts of a set of conventional, 2-port, single-ended S-parameters into a 1-port differential impedance. Grounded Coplanar Wave Guide. Calculate a wavelength in the presence of a dielectric. To model it, we may use the Si6000b Differential Surface Coplanar Waveguide by spacing the coplanar reference planes far away from the signal tracks until there is no further increase in impedance. Frequency: Frequency at which the stripline is analyzed or. INPUT DATA. This medium consists of a center conductor with ground planes on either side and below (Figure 4). C = Speed of light. Coplanar GB waveguide calculator C-Coupled Resonator designer Coax Impedance calculator Chip Resistor De-rating calculator dBm/Linear power converter. e. When use the calculator, put values in the velocity of propagation field and the dielectric constant field. a Cross section of a differential coplanar capacitor, with metal conductors from − ∞ to − b , − a to a , and a to ∞ . But practically (especially in a dense design like your example), they also interact with surrounding conductors, and the coplanar ground, or ground beneath a differential microstrip will affect the characteristic impedance. Don’t forget to check out our other. RF and microwave transmission lines connect different components on a PCB board. Click here to see the user guide of our impedance calculator. The electric field distributions of these two. Based on:Coplanar GB waveguide calculator C-Coupled Resonator designer---- Butterworth Prototype---- Chebyshev Prototype Coax Impedance calculator Chip Resistor De-rating calculator dBm/Linear power converter. Coplanar Waveguide Calculator. After optimizing the mathematical model of strip coplanar waveguide, reference plane and differential vias, we built a simulation model of the backplane passive link which met the 100GBASE-KR4. The backside of the strip can be made of air or metal (grounded coplanar waveguide). Track Thickness: mm. @emilysilver. 36 Differential coplanar structures Reduce time to market Graph production variations Single ended and differential modelling Calculate the effect of resin rich areas Enhanced soldermask models Optional track resistance calculator Si8000m – comprehensive modeling of over 100 structures. Differential surface coplanar waveguide with ground calculator. But the choice of transmission-line technology, such as microstrip or grounded coplanar waveguide. 9. Unfortunately, TxLine doesn't do coplanar waveguide for differential traces. This is (in part. The following formula is used to calculate the cut-off frequency, lower & higher operational frequency of the rectangular waveguide. 2. A differential length in real space (i. This paper based on the theory of transmission lines, according to the coplanar waveguide (CPW) structure, designed a high-speed differential connector which was separated by air. 2. As a quick comparison, microstrip circuitry features a signal conductor fabricated on top of a dielectric layer, with a conductive metal ground plane on the bottom of the dielectric material. This means putting vias to 'stitch' the top and bottom planes together, along both sides of the conductor, to surround it with the ground connection. Coplanar Waveguide With Ground For Coplanar Waveguide with ground or Microstrip lines with signal side ground plane, showing the formula by Brian C Wadell. To further reduce the trace width, you can go for a "differential coplanar waveguide with ground" topology. To avoid microstrip modes, have h >> (w+2g) and extend component side ground away from the trace by > (w+2g). *Strictly, a loss quantity when expressed in dB should be positive. Gupta in [3] lists various types of CPW: CPW with finite dielectric thickness, CPW with finite width ground planes, CPW with a cover shield, conductor-backed CPW with a cover shield, conductor-backed CPW, multilayered CPW, asymmetric CPW and asymmetric CPW. PCB Coplanar Waveguide Calculator RF PCBs can be complex boards that need careful interconnect design and layout. This technique is preferably used in a multilayer PCB design, and the signal trace is backed either with or without by the ground. This kind of port simulates an infinitely long waveguide connected to the structure. Assuming FR-4. It acts like a filter, allowing only microwave signal frequencies within a certain bandwidth. Rho: Conductor resistivity relative to copper. Where, f c = Cut-off frequency of rectangular waveguide in GHz. Ls =. The coplanar option designs a grounded coplanar waveguide structure.