Useful converters and calculators. For example, if you wish to input "25000000", just type "25M" instead. Signal generators are usually rated in dBm output (for 50 ohm systems) which can be converted to peak volts, as needed. Q is the quality factor of a parallel RLC circuit (dimensionless),. ) In contrast, a 600-Ohm line matched to the antenna presents a 12:1 impedance. 675 ohms. 🔄 Convert Volt to dBm Formula VRMS = SQRT (Z/1000)*10 (PdBm/20) where Z is the. The air lines currently used as impedance standards are discussed in section 4, below. Asymmetric and symmetric versions of a stripline can be implemented with this calculator application. You can do it with a couple of slightly. Example : INPUTS : Fc =900 MHz, Z0 = 50 Ohm OUTPUTS: L = 1. Ideally you will have an impedance that you have been asked to achieve, typically something in the range of 40 to 90 ohms. Four-Step Guide: Determine the ohms rating for each speaker. So the phrase "minimum loss pad" is a cruel joke indeed!Coaxial Cable Impedance (Ohms) Impedance is the amount of resistance waves moving through the coaxial cable encounters. It depends on the speaker’s efficiency and design, but a rough estimate is that a 4-ohm speaker can handle around 50-100 watts RMS power. The inductive reactance in ohms will also be calculated. 15% survive three. Try our differential stripline impedance calculator, built based on Wadell’s equations. 75 ohms is quite close, and 140 ohms through a λ 4 λ 4 of 75 ohms comes out to be 40 ohms. Above 5 GHz, you'd generally want to carefully design your via to maintain impedance matching as well as possible. Their combination results in the transformation of the load impedance into 50 Ohms at the input of the second line section. The most common values of coaxial cable impedance are 50 and 75 ohms. Headphone. distribution of impedance is minimum at the center and maximum on the both edge of patch. 3mm) and calculate the anti-pad (AP) size that is required to present a nominal 50 Ohm impedance at this point. The radius of the circle is the reflection coefficient G , where the radius to the edge is 1. also attenuates line noise with a current. 0 value of the line to this point on the chart—50 Ω for a 50-Ω line, for example. To use the calculator, select your drive voltage units from the dropdown, enter your two known values into the appropriate fields, click calculate, and the converted power, drive voltage, or speaker. PCB Impedance-Calculation: Help with the dimensioning of the impedances of your circuit board. 6mm thickness and the connector is a SMA. The quick answer is that 50 ohms is a great compromise between power handling and low loss, for air-dielectric coax. You also want enough turns so that the magnetizing inductance is sufficient, at the lowest frequency, to provide a primary impedance much larger than 50 ohms (>10 times) with no secondary load. Using the Microwaves101 microstrip calculator, we see that 50 ohms on 10 mil alumina corresponds to 9. In fact, striplines often make components such as band-pass filter's more accurately, with more symmetric roll-off and no lower cutoff frequency. The differential pair impedance calculators you'll find online provide a good first estimate of the impedance you can expect for your particular geometry. Figure 1. Output field. This L1 is equivalent to a short power line of 25m from a low Z distribution transformer to the DUT. 2, the following formula can be used: Zo = 138 * log10 (D/d) / sqrt (εr) where Zo is the characteristic impedance, D is the diameter of the outer. (Default Values Below Usually Work Well For Line to Mic Attenuation) Input Impedance (Source impedance) (600 ohms for modern rigs) Impedance matching on antenna is done by measuring reflections in a splitter or the maximum Return Loss by trimming dipoles for example. This tool helps you create a matching circuit so that optimal power transfer occurs between unmatched loads. Our capacitive reactance calculator helps you determine the impedance of a capacitor if its capacitance value (C) and the frequency of the signal passing through it (f) are given. While commonly constructed using printed circuit boards, this structure can also be built using other materials as long as the…Inductance of the inductor (L) H. Why is 50 ohm used? The 50-ohm impedance is commonly used in RF (radio frequency) systems due to its compatibility with coaxial cables and minimizing signal reflections. You can use the web calculator provided and here's an example of matching 50 Ω to 300 Ω at 10 MHz: -. Z RLC is the RLC circuit impedance in ohms (Ω),. At low frequencies near 0 GHz, the input impedance is inductive since. Both the S-parameter and input impedance are complex numbers (R + jX), where R represents the real component, and the X represents the imaginary component. The calculator produces more accurate results than the IPC formulas for impedance because it. USA. This standard was the. 39 for the effective dielectric constant. This calculator is designed to help calculate the value of the resistors R1 and R2 to be used in T-pad attenuator. Fortunately, a 1/4 wave each of 50 ohm and a 75 ohm paralleled will provide a 30 ohm cable. The 50 Ohm line is connected directly to the load, usually the antenna. This technique doesn’t work for wide band requirements, but is a simple way to achieve this at a specific. Z is the impedance of the circuit, typically measured in ohms (Ω Ω). The following formulas are used for the calculation: where . 7 gives 49. Factors affecting this are the size and materials of the cable. 50Ohms) and Z_A the impedance of the antenna at its footpoint. 8-j0. Make sure it is within your headphone's input limits to avoid damage. The wave propagates in both directions down the transmission line until the ends are reached. If we make the line width wider, we have to make the dielectric thicker to preserve the 50 Ohms, and this keeps the capacitance the same. One useful rule of thumb is that a trace will have approximately 50 Ohms impedance when the trace width is double the height from trace to plane. 5 = 12. For a pure inductor of inductance L Henries, the impedance ZL= jωL Ohms. where X c is the capacitive reactance. 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. 7 MHz and the reference impedance is Z 0. Here, my simulation source is a simple AC source (labelled V2, found in the Simulation. This is 1. Since the load has a real part of 9. f c = 1 / (2π × 3. Pi LPF calculator. Square both R and X, and add the two products together. Background S11 is the input reflection coefficient with a. This calculator helps you calculate the characteristic impedance of a coaxial cable given its dimensions. This shows the return loss of the L-network with a coaxial 75Ω load from 88 to 108 MHz. Lcoax ≈ μ0μrL 2π ln( D d) L c o a x ≈ μ 0 μ r L 2 π l n ( D d) Where: Lcoax L c o a x = inductance of the coaxial cable in henries (H) μ0 μ 0 = permeability of free space = 4π×10 −7. 50 Ohm Transmission Line Calculator; Circuit Board Trace Width Calculator; 50 Ohm Pcb Trace; 50 Ohm Trace Width Calculator Formula; The above screen shows that the target parameter is 'Trace Width (W)' and the fixed parameters are 50 ohm Char. Enter the inductance and frequency values, select the units and click or tap the Calculate button. For this article, we are going to design an L-Network that matches a 75 Ohm source (function generator) with a 1 kΩ load (resistor). DDR4 Impedance Values. The impedance of this line in ohms can be estimated with Eq. In practice, we will never have a perfect, ideal system. Matching Pi Attenuator Calculator. The L-match impedance matching circuit is one of the circuits used to match the impedance between two points, usually a source and a load. This calculator computes the trace width of a stripline if the maximum current, trace thickness, temperature rise, ambient temperature and length are given. Activity points. Enter the source characteristic impedance and the load impedance then press "Calculate" below. I - Current. Matching T Attenuator Calculator. The solution built into the above calculator enforces. 4. Following is the list of useful converters and calculators. Enter the inner diameter, outer diameter, and relative permittivity of a coaxial cable to calculate its impedance, inductance, capacitance, and. A transformer turns ratio calculator; calculates the turns ratio needed to match a given primary impedance to a given secondary impedance. The formula to calculate impedance is: Where. - For the obtained Zo in your Smith Chart calculate. The gap changes to retain these ratios for different 50 Ohm cables. 913 2. To enter the Infinity value, just type inf in the input box. Headphones with impedance of 32 ohms would be louder than 48-ohm headphones with the same signal voltage because there would be more power on account of the lower load resistance – provided that the amplifier has low source resistance. φ is the phase difference between the total voltage V T and the total current I T in degrees (°). ω = 2πf is the angular frequency in rad/s, . There are at least two ways to calculate it. This calculator will determine the Power in dBm when the voltage value (V) is entered into the input. This calculator is designed to calculate the characteristic impedance of a microstrip - a flat conductor suspended over a ground plane with a dielectric between them (see diagram below). Figure 3. 8 Ω. The following formulas are used for the calculation: where . INPUT DATA : Source Impedance: Ohms: Load Impedance R: Ohms: Load Impedance J: Ohms : RESULTS : Absolute Load Impedance: Ohms: Load Reflection Coefficient: Load VSWR: Load Return Loss: dB: Load Mismatch Attenuation: dB :I wanted to use Altium to calculate the width of the trace automatically, so that it had a 50 Ohm impedance. Characteristic Impedance Matrix [ohms]: 1 2 1 49. 75 mm=30 mil). Access a free differential stripline impedance calculator tool for PCB transmission lines. 4 j Plot this at point z1. The microstrip is a very simple yet useful way to create a transmission line with a PCB. Yes, we did that without a calculator. Calculations are made using the formula below: Where: Enter the frequency and inductance into the calculator, choose the. High-quality circuit boards as prototype and series at reasonable prices. Reactance is a more straightforward value; it tells you how much resistance a capacitor will have at. Enter Secondary Impedance (Z sec ): Ohms. Post subject: 50 Ohm TO 75 Ohm Posted: Wed Feb 21, 2007 12:53 pm . The tee (T) attenuator (pad) formula in the calculation for resistor values is measured in Ohms. Since inductive impedance is proportional to frequency, the lower the frequency, the more turns are required for a given impedance. Set the scope input impedance to 50 Ohms. This transmission line calculator calculates the impedance at input and attenuation of a given transmission line once terminated with the given load. This calculator will help you determine the correct values for the inductor and capacitor in a Pi match impedance matching. Q = √ ( (R2/R1) – 1) where R2 > R1. 077 x 10-12 farads Pi low pass filter Formula. Overview. 68 are connected in star to a 400 V (line voltage) 50 Hz symmetrical three-phase supply. It is a current source (hi-Z) driving a voltage sink (low-Z) . R is the resistance in ohms (Ω),. RF & Wireless. Typically, a bias tee is designed for a 50 ohm impedance, allowing it to match the impedance of the RF system. A matched impedance network is always 50% lossy yet maximum power is transferred. 2. 50 ohm output is pretty much standard for function generators, as it is a match for the 50 ohm coaxial cables that are often used to interconnect equipment. The board contains two inner layers of GND and a ground plane around the RF track: To decide the thickness of the RF track, I used an online calculator:. In this case, the total effective resistance is 2 Ω. In schematic, write an equation for port 2 Term Z to be 35 ohms above 400 MHz: Z = if freq < 400 MHz then 50 else 35 endif. Analyze. Fortunately, a 1/4 wave each of 50 ohm and a 75 ohm paralleled will provide a 30 ohm cable. The Datasheet says that the target impedance of the RF Trace should be 50 Ohms as a controlled impedance. 50-60nF), which means variable capacitors are not a viable option. Spacing and width value pairs that will give a differential impedance of 100 Ohms on Dk = 4. A cable with a characteristic, or surge, impedance of 50 ohms behaves as a 50-ohm resistor to any voltage surges impressed at either end,. What levels of impedance are there?. 50 Ω and 75 Ω. 75 Ohm cable depends heavily on what radio frequency you're trying to transmit. D D = coaxial cable outer diameter. Set the attenuation to 40 dB in the second box of the calculator. Use DigiKey’s Ohm’s Law calculator to calculate the relationships between current, voltage, resistance, and power in simple resistive circuits. INPUT DATA. 87° (Equation 1). 4mil. Board. At very high frequencies, certain 75 Ohm cables work better than 50 Ohm. It will make at least a small reflection. An embedded microstrip is a microstrip transmission line or flat conductor separated from the ground place via a dielectric material. In order to match your 50 ohm cable to the 75 ohm cable, you'd need to insert a 1/4 wave section of transmission line between the two. Z RL is the RL circuit impedance in ohms (Ω), . Right-click on ‘Net classes’ >> click on ‘Add classes. Left-Hand Circuit: 50 ohm line-to-line, no chassis connection 5. 1. A Delta Match is intended for matching a driven element to 300-600 Ω balanced feed line. 76 x 10-8 Henries, C = 7. 03556mm. You’ve probably also seen some calculators. The decision to use low impedance, 4 ohm or 8 ohm loudspeakers, or a high impedance (often called “Constant Voltage” or “70Volt”) system is not a straight forward matter in system designs that use large format loudspeakers or are distributed over a substantial distance. These equations are relatively simple compared to other transmission line. The second major factor which affects impedance is the distance from trace to the nearest plane. This calculator computes the trace width of a stripline if the maximum current, trace thickness, temperature rise, ambient temperature and length are given. 52mm. Note: Units for width and height must be consistent Calculation Width: Result: This online microstrip impedance calculator calculates the characteristic impedance of the microstrip (Ω), W/H ratio, and effective dielectric constant (εe) by entering the value of dielectric material relative permittivity (εr), the width of the copper trace (W), and dielectric height (H). The Pythagorean theorem is written: c 2 = a 2 + b 2. You can build an RC low-pass filter with a cutoff frequency of 1 kHz using a 3. A 50 to 75 Ohm matching pad which always exhibits 5. The history of 50 Ohm impedance goes back to the late 1920s/early 1930s, when the telecom industry was in its infancy. impedance ratios other than 1:1 because accommodation must be made for the impedance of test instrumentation, which is generally a constant 50 or 75 ohms. The input capacitor, C1 acts as an open circuit and. The Ohm's law formula can be used to calculate the resistance as the quotient of the voltage and current. The reflection coefficients at each boundary in Figure 7. I am developing a 4-layer FR-4 board containing a GNSS receiver (L1 + L2). An Inductor Impedance Calculator is a tool used in electrical engineering and electronics to calculate the impedance of an inductor in an alternating current (AC) circuit. IPC 2141 Trace Impedance Calculator The IPC-2141 trace Impedance calculator will help make initial design easier by allowing the user to input basic parameters and get a calculated impedance according to the IPC-2141 standard. b. Following is the list of useful converters and calculators. 1) Enter the required input impedance, output impedance and attenuation then press "Calculate" below to obtain. Z = Impedance of circuit element (i. f is the frequency in hertz (Hz), . The image below shows an example Smith chart used to plot the impedance Z = 1. Speaker impedance (Ohms): Fill in the speaker Ohms value for as many or as few speakers as you’d like. 5. You want to set R T to equal the differential characteristic impedance of 100 Ohms, so there is no reflection. You want to set R T to equal the differential characteristic impedance of 100 Ohms, so there is no reflection. The twisted pair helps create a more uniform inductance and capacitance per unit length of wire to ensure a constant impedance, by keeping the return path as close to the signal as possible. The microstrip calculator determines the width and length of a microstrip line for a. Enter the values of trace width (w), trace thickness. Equation. It is a theoretical thing. You need at least a 2D field solver. Simulate and then insert a list ofThe purpose is to stabilize variations in line impedance using L1 which raises the impedance to above 50 Ohms above 150kHz for conducted emissions between 150kHz and 30MHz. To use this tool, enter the desired value of dB attenuation. This page allows you to calculate the impedance required for a 1/4 wave (electrical) section of line. Z O is usually a real impedance. The second major factor which affects impedance is the distance from trace to the nearest plane. Consider a DC photovoltaic Solar cell. 5mm pitch. It helps you determine the total impedance (in ohms) when connecting speakers in series or parallel. All the S parameters r available in. The Tee attenuator. A sine wave signal generator with 50 ohm output impedance that produces a reasonable level is needed. Stack Exchange Network. This tool will also compute the resistance of the stripline, the voltage drop on it, and the resulting power dissipation. This can be achieved by regulating the inner and outer diameter of the coaxial cable, along with the. Impedance is a complex quantity that characterizes how a component, like an inductor, resists the flow of AC current. space. Attenuation field. From the voltages measured, I'd estimate the output impedance of the Nano at around. Z is the impedance (usually RF systems have 50-ohms impedance)Our headphone power calculator is designed with user-friendliness in mind. Yoni Calculator Online Test System Configurator ezSample (Free Samples). This tool will help you create a matching circuit so that optimal power transfer occurs between unmatched loads. A via represents such a small part of the overall track impedance that the via can be ignored except for extremely high frequency signals. 1-2 GHz is kind of a messy middle ground where you might get. Bookmark or "Favorite" this microstrip line impedance calculator page by pressing CTRL + D. 36, from Equation 6. Captain. Keep in mind that the reactance of the ideal inductor has the same magnitude as its impedance. Coaxial Cable Impedance Calculator. For dipole antennas with an impedance greater than 50 ohms you will need a step up impedance transformer (e. Just enter 2 known values and the calculator will solve for the others. This tool calculates resistor values to build an attenuator that matches this value of impedance. Display the answer in ohms. 25 inches and a dielectric constant of 2. A Target Impedance of 50. 25 x 50 ohms). The impedance of the line is mainly depending on your PCB characteristics. Using the calculator, the recommended amplifier wattage is between 1800 W and 2400 W and the impedance should match the impedance of the sub at 2 Ω. For example, a 1 Watt power amplifier (source) optimized for use in a 50 Ohm system will. This will give the highest bandwidth measurement and lowest noise level. The circuit got its name because the inductor and the capacitor form a Pi symbol (see schematic below). 1) If using 50-ohm series resistor on each signal line, do the traces still need to be 50-ohm impedance controlled on PCB? 2) And if so does the impedance need to be controlled. One useful rule of thumb is that a trace will have approximately 50 Ohms impedance when the trace width is double the height from trace to plane. Just as simple as Ohm's law itself. φ = 0° if 1/2πfC = 2πfL. Online impedance calculator. Figure 7. Values of 50 Ω 50 Ω and 75 Ω 75 Ω also offer some convenience when connecting RF devices to antennas. The following simple circuit provides "6" dB attenuation and 50 Ω Ω input impedance, assuming that the load at the output is also 50 Ω Ω. When RF engineers think about the impedance of their project’s transmission lines, they may automatically assume that these lines all have a nominal impedance of 50 ohms (Ω). This can be built into a FLEXI-BOX and a transmission line (50 Ohm track) PCB is available which easily adapts for this circuit with one simple trimming. To calculate the dimensions, you cannot use a simple impedance calculator. Display the answer in ohms. Archimedes constant (π) Impedance Calculator Results (detailed calculations and formula below) The Impedance of the circuit is Ω. For 25 ohms, we calculate 31 mils line width and 7. 9 Ω, R₂ = 3,062 Ω, and R₃ = 50. IPC 2141 Trace Impedance Calculator The IPC-2141 trace Impedance calculator will help make initial design easier by allowing the user to input basic parameters and get a. These cables would also span long distances, reaching hundreds of miles. Enter the nominal impedance of the destination device you will be feeding audio to. This characteristic impedance is close to the desired 50-Ohm impedance, so the example can proceed with the design using these microstrip lines. Access technical papers, white papers, calculators, tools and more for circuit laminates, prepreg and bonding materials. What are Impedance Matching Pads? Impedance Matching Pads/networks are used to match circuits with different impedances. To learn how to calculate resistance and. Following is a simple LC based Pi filter calculator used for low pass filtering. 7E-6 [Ω · cm] L is the trace length [cm] T is the trace thickness [cm] W is the trace width. Ohms. We will use the Smith Chart to calculate a tuner that matches a 25 ohm resistive load to a 50 ohm transmission line at 100 MHz. INPUT DATA : Source Impedance: Ohms: Load Impedance. This is called the impedance. The impedance of an inductor is dependent on its. Understanding the total speaker ohms is essential to ensure compatibility with your amplifier. (Default Values Below Usually Work Well For Line to Mic Attenuation) Input Impedance (Source impedance) (600 ohms for modern rigs)A characteristic impedance formula will only be specific to a given circuit, and it can be calculated from that circuit’s various elements and components. 37mm for a 50 ohm. Suppose you have a coil with an inductance (L) of 0. Most digital protocols use 50 Ohms single-ended impedance, but only when the trace is long enough. Connect the signal generator to the scope using the 50 Ohm BNC jumper coax (no 50 Ohm terminator at the scope input) Set the signal generator output impedance to 50 Ohms. Here is a short list of potentially useful calculators for your endeavors: Ohm's law calculator; Wire resistance calculator; PCB trace current calculator; and; PCB trace resistance calculator. 5. Q is the quality factor of a parallel RLC circuit (dimensionless),. 4 2 6. 2: Stepped-impedance transmission line transformer with the n th section having characteristic impedance Z0n and electrical length θn. 3. Enter Zo - source characteristic impedance in Ω S11 - either linear or dB value can be used The tool will calculate the absolute value of the load impedance ZL in ohm. These quantities - source impedance, line impedance and load impedance, respectively - must equal one another (impedance matching]) to ensure the efficient transmission of power. KV LL = Base Voltage (Kilo Volts Line-to-Line) MVA 3Ф = Base Power. Both the unit and the rule are named after Georg Ohm - the physicist and inventor of Ohm's law. Antenna feed The λ/2-length antenna shown in Figure 2 is called a dipole antenna. If you have two resistors – one large and the other small in parallel, the effective resistance is closer to the smaller value. Why is impedance 50 ohm? An impedance of 50 ohms is a common characteristic impedance used in RF (radio frequency) transmission lines, such as coaxial cables. Divide the 1/4 wavelength by the velocity factor to get the electrical 1/4 wavelength. When viewed as a simple electronic circuit, the impedance of the audio source may be written as output (or source) impedance, while the impedance of the headphones may be considered load impedance. The surface finish is neglected. If a short section of a 50 ohm cable has a 75 ohm impedance, then 33% of the voltage signal will be reflected at each end of the 75-ohm section. It’s not an arbitrary number; there are good technical reasons for. For something like a line driver or transceiver, you may have 50 Ohms impedance implemented at the source end of the line. 4. Guideline for Impedance Matching (simplified cases) 1. 50 ohms is in the middle, short circuit on the left, open circuit is on the right. The phase is mostly + 90 ∘ or − 90 ∘, indicating that Zin is mostly reactive. This means that the actual trace width for a 50 ohm line could vary from design to design. This says that ALL 50 Ohm transmission lines in FR4 have exactly the same capacitance per length. Capacitance – the impedance calculator uses the Impedance value to calculate the capacitance per unit length. To calculate impedance, calculate the resistance and reactance of the circuit, then label resistance as R and reactance as X. With our handy calculator, you can choose from 50 Ohm, 75 Ohm, 93 Ohm and 95 Ohm coaxial cables. Any other impedance at the output causes an impedance transformation because the SWR is not 1:1. From the chart horizontal load of 20, go up vertically to the horizontal line from 50 on the left vertical scale. So, the impedance of the coil in. D D = coaxial cable outer diameter. Ohm's Law states that the current through a conductor between two points is directly proportional to the voltage. Good luck, Al. . Therefore, if you want to deliver the most RF power from your 50-ohm source to your antenna - voila, only a 50 ohm. The Tee attenuator (T-pad) is a specific type of attenuator circuit which resembles the shape of the letter "T". Both input and output impedance is set to a default value of 50 Ω. Impedance is a complex quantity that characterizes how a component, like an inductor, resists the flow of AC current. S-Parameter to Impedance. A perfect match corresponds to Γ = 0, and a complete discontinuity (in which all the energy is. Calculates the resistor values, attenuation, minimum attenuation, impedance, reflection coefficient, VSWR and return loss of an impedance matching T attenuator. The Smith Chart is your friend. S11 Linear to dB. Please note that the generator's output impedance is NOT selectable - is is ALWAYS 50 ohms. 6. L is the inductance in henries (H),. With most speaker amplifiers the HE-6 would need no attenuation at all. 1. Enter the nominal impedance of the destination device you will be feeding audio to. Ohm’s Law Calculator. R is the load impedance, and is typically 50 Ohms for RF systems. About 11% of the signal will survive one round trip, 1. Agilent's LineCalc tool calculates Z odd = 50. One of the most common is FR4. The default impedance (Z) is 50 ohm, although you can change that to any value. Significantly, the on-line calculators that invoke Q factor as a parameter don't appear to justify what it means or how to use it. Further the Smithchart will also changed to 75 ohm impedance. I used some online calculator to calculate parameters of trace so it has 50 Ohm impedance. Note: The results are only for approximation and rough estimation, the final values and the. This tool calculates resistor values to build an attenuator that matches this value of impedance. A basic rule of thumb is that the width of the trace is about equal to the thickness of the dielectric material to achieve a 50 ohm impedance on the line. 02 Amps. 2 in. Adapters; Amplifiers;. 6), the impedance will be approximately 50 Ohms. It states that V (voltage) = I (current) * R (resistance). The circuit got its name because the inductor and the capacitor form an L-shape (see schematic below). You can use this formula for individual resistors in a parallel circuit. φ = –90° if 1/2πfC > 2πfL. The 50 ohm path is typically much lower noise. Attenuation field. The system impedance might be a 50 Ohm transmission line. The board contains two inner layers of GND and a ground plane around the RF track: To decide the thickness of the RF track, I used an online calculator:. A common dipole, driven from the center and 1/2 λ above ground, will exhibit approximately 72 Ω of impedance. As other answers have said, there's numerous online calculators and high priced tools available to help you do that. Enter the Impedance and required attenuation level to get values for R1 Zo(Ω). High-speed designs carry a requirement for controlled impedance, crosstalk control, and the need for interplane capacitance. It will make at least a small reflection.