When this is coupled with the fact that RF wavelength is inversely proportional to the magnetic field strength, the wavelength inside the body (about 26 cm at 3 T) may be shorter than the dimensions of. For example, if you wish to input "25000000", just type "25M" instead. To calculate the skin effect (or skin depth), follow the given instructions: Multiply the frequency of the signal with the relative permeability of the conductor, the permeability of free space, and π. Here you can see that the total length of cable being used is 19. For an array of apertures the complete formula is: SEdB=K log10 λ/2 L - 20 log n L. This calculator computes the trace width of a microstrip given the following information: maximum current, trace thickness, temperature rise, ambient temperature, and length. RF Calculators. Provide the value for the wave velocity in the medium. Also, explore tools to convert gigahertz or wavelength in nanometres to other frequency wavelength units or learn more about frequency wavelength. Calculator 1: This calculates the Resonant Frequency of the LC tank circuit by entering the inductance and capacitance values. So for a 3G cell phone that operates at a frequency of 2. The antenna factor describes the connection between the electric field intensity E around the antenna and the antenna's voltage output V. FREQUENCY (f) Out of range value [8. Write down the inductance L in henries. In the V2400 version, at present under construction, we have upgraded this calculator with a better user interface, making use of up-down controls to change the main input parameters. Following calculator calculates lowest cutoff frequency of rectangular waveguide as per TE10 mode and equation-2 that is Fc = c/2a , where 'c' is speed of light and 'a' is large dimension of waveguide. By continuing to use this website, you consent to cookies being used. Amplifiers Amplifiers. Where, f c = Cut-off frequency of rectangular waveguide in GHz. Equation $$\lambda = \frac{c}{f \sqrt{\epsilon_{R}}}$$ or $$\lambda = v_{p}\frac{c}{f}$$ Where: $$\lambda$$ = signal wavelength The reason it’s not exactly half wavelength (35 cm in this case) is because of the end effect* and a resulting multiplication by 0. However, this can be automatically converted. 5 Ohms Whip Antenna Formula. Radar cross-section ), denoted σ, also called , is a measure of how detectable an object is by . The guide wavelength is a function of operating wavelength (or frequency) and the lower cutoff wavelength, and is always longer than the wavelength would be in free-space. Enter the values of operating frequency and relative dielectric constant then click on calculate to get the effective dielectric constant and guide wavelength for any slotline. 13mm (depends on manufacturer's specs) and you get a trace width of ~0. more ->Since light is an electromagnetic wave, the speed of the wave is 3 × 10 8 m / s and the equation f = v λ can be used. The RF link is between a transmit antenna and a receive antenna. 3kHz to 11. If you want to calculate the Frequency from Wavelength - Click here to use the Wavelength to Frequency Calculator. eA = Efficiency of the aperture (between 0 and 1) λ = Wavelength of radio wave in mm/cm/µm/metre. Verify the result with our sound wavelength calculator. 3. Formula. 1: Impedance-matching using a quarter-wavelength transmission line. 4 GHz. However, the frequency ν describes the temporal frequency of the radiation. | FREE DOWNLOAD 01 November 2023, 18:15 CEST >100. Items (3), (4), and (5) above represent RF or power losses which can be measured. Calculate: Plug the gathered values into the formula to calculate the far-field distance. Formula. 3/4 and 1 1/4 and 1 3/4 and so on are also. Dipole antenna calculatorFm 23-10 chptr 7 communications 5/8 wave 2kw vertical high gain fm broadcasting antennaAntenna length wavelength. For example, at a frequency as high as 300 GHz, the wavelength of a radio wave is approximately 1 millimetre. The next step in calculating transmission line metal loss is to find the RF resistance per unit length R' (convert Ohms/square to Ohms/meter), based on the physical dimensions of the structure and the RF sheet resistance. While a solid plane of material is best, cages made from mesh are common. Editorial Team - everything RF. Find the wavelength of a radio wave with a frequency of 101. 55). Speed of light = (frequency) * (wavelength), where frequency is in Hz, wavelength in meters, and speed of light = 2. Frequency. RF calculations and RF conversions include metric. Wireless/RF; Or try an example search: Resistor Color Code Calculator. To use the calculator, enter the desired operating frequency in megahertz to get a starting length in both feet and meters for building a quarter-wave vertical antenna . Enter your desired frequency (MHz) of operation (i. Pasternack's Circular Waveguide Calculator will calculate the cutoff frequency for the device from its radius. Fairview Microwave's TEM (Transverse Electromagnetic Mode) Wavelength Calculator allows you to determine the wavelength (in millimeters) inside a rectangular wave guide given the frequency and dielectric constant (or VoP) of the input signal. Input voltages are RMS values. To be more specific, it is the ratio of the electric field intensity E to the voltage V induced across the antenna output terminals. 4 (for typical FR-4. 35 meters. Band name Abbreviation ITU band Frequency and wavelength Example uses; Tremendously low frequency: TLF < 3 Hz > 100,000 km: Natural and man-made electromagnetic noiselength = wavelength(in cable) * (phase shift in degrees/360), where the wavelength(in cable) = 0. EXAMPLE of Whip Antenna Calculator: INPUTS : Frequency = 900 MHz, Length = 12 inches, Diameter = 0. All Conversion Calculators. 2. User assumes all risks for its use. 62607015E-34 m² · kg/s. At 300 MHz, for example, the electromagnetic wavelength in brain tissue is approximately 13. 1. Zp= Input/Primary impedance. On the other hand, at a frequency as low as 30 Hz, the wavelength is about 10000 kilometres. When the dimension of an opening in an EMI shield is equal to one-half the wavelength of interference, then the shield radiates EMI and becomes useless. However, it rarely causes any problem at low speeds. I've learned recently that lower frequency radio waves travel farther and have better object penetration than their higher frequency counterparts. We've set it to $$343. a) Find the shortest wavelength AM radio signal. This example is for TE 1,0 (the mode with the lowest cutoff frequency) in WR284. The frequency is equal to the speed of light in a vacuum divided by the wavelength. It will also show you what the. Height: Height of the substrate. 20KHz doppler frequency formula or equation for moving reflector. Microstrip line is a widely used transmission line and for the appropriate transmission its characteristic impedance has to be calculated while using it in RF design & circuits. . At the quarters or 1/4 (90 degrees) and 3/4 (270 degrees) wavelength the current is the highest and the radiation is greatest. Wavelength and frequency calculator; Intermodulation calculators. RF_N CC2420 BALUN TX/RX Switch ANT PA LP filter TX path RX path Control logic and bias network RX current 19. Suppose you have an antenna with a diameter (D) of 4 meters and you’re working with a wavelength (λ) of 0. The first section, Section 3. 5 Hz This wavelength to frequency calculator helps determine the frequency of a waveform based on its wavelength. λ = Wavelength. λ = Wavelength of EM wave; c 0 = Speed of. Other uses include acoustic measurement and adjustment, microphone placement, room tuning, and speaker positioning. The width of the conducting layer is important to calculate the radiation intensity since it directly affects. “468” is the constant used to convert frequency in MHz to feet. As you’re probably aware, signals travel on PCB traces with a certain speed. The FCC limit for public exposure from cellular telephones is an SAR level of 1. User assumes all risks for its use. 979 meters. Wave Characteristics . The Frequency from Wavelength calculator computes the RF frequency (ν) based on the wavelength (λ) and the speed of light (c). Ae = Effective antenna aperture in m 2. The change in period between these two frequencies is 2 ps (that is, 1/99. Enter the Frequency to be converted. e. The fact that there is a 20 metre cable going to an earthing plug somewhere cannot possibly affect the interactions between an EM wave a couple of centimetres across and a hole in the mesh of comparable size. P. A quarter wave transformer is used to match two transmission lines with different impedances. 020 - Updated: 2023 - mwave. The efficiency varies and generally gets lower with wider bandwidths. The free space path loss is the loss in signal strength of a signal as it travels through free space. 54 lambda. In electrical engineering, electrical length is a dimensionless parameter equal to the physical length of an electrical conductor such as a cable or wire, divided by the wavelength of alternating current at a given frequency traveling through the conductor. A television station broadcast Radio Frequency (RF) channel is allocated 6 MHz of bandwidth for over-the-air transmission in part of the VHF or UHF Radio Frequency Band. The result will then be displayed in the answer box along with a dynamic conversion scale to show how wavelength varies for different frequencies, above and below the entered value. )For a Signal Traveling in Free Space - *λ = c (Speed of Light) / f (frequency). FREQUENCY (f) Out of range value [8. To find the half wave, divide that number by two. The formula used in the Far-Field Calculator is: d F = λ 2 ⋅ D 2 Example. The cut-off frequency of the coaxial cable represents the maximum upper operating frequency of the cable. For a parabolic antenna, the gain is calculated by the formula: Ga = 10lg (k (πD / λ)2cos (Φ)) Where: Ga — gain; k — efficiency of antenna surface utilization (approximately 0. Air is thin enough that in the Earth's atmosphere radio waves travel very close to the speed of light. Download: RF & Microwave Toolbox lite APK (App) - RF ＆ Microwave Toolbox lite APK - Latest Version: 4. This parameter is termed as the propagation delay. 1 meters. 22mm. On our example FR-4 PCB operating at 6 GHz, a wavelength may be calculated from the well known formula as, Where F = MHz, λ (wavelength) = meters, Er = 4. Simons, "Coplanar Waveguide Circuits, Components, and Systems", Wiley. Our RF and microwave calculators and converters will provide the figures you need for your radio frequency engineering needs. 3. RF reflection results in attenuation and interference. Quater-wavelength in meters: 71. WinRFCalc, the best RF calculator toolbox for Windows. In a circular waveguide. It is a good starting point. The PCB material will be FR-4 with 1. 0 GHz (or wavelength 6 cm). 1/10 λ. Wavelength to Frequency Calculator. The R f value is a physical constant for organic molecules. The waveguide width determines the lower cutoff frequency and is equal (ideally) to ½ wavelength of the lower cutoff frequency. As radio waves penetrate into soil the wavelength is shortened and the amplitude rapidly attenuated. UK Radio Frequency Allocations (graphical) US Radio Frequency Allocations. This calculator computes quarter-wave, half-wave, 3/4-wavelength and full-wave dimensions of the coaxial cable segment knowing inner insulation material. Guide wavelength is defined as the distance between two equal phase planes along the waveguide. RF wavelength calculations can be made quite simple with two basic formulas. Disclaimer: This calculator has been tested and is believed to be accurate to 6 significant figures. It is required to calculate physical length for different degrees of electrical length for dielectric substrate. 85419 x 10. nl - Free - Mobile App for Android. However. Doppler shift is an apparent change in frequency (and, correspondingly, wavelength) due to the relative motion of two objects. com +1 (718) 934. Wilkinson Power Divider Calculator. , the power level of 0dBm represents 1milliwatt). The gain of the conical horn antenna can be calculated by the following formula. Convert frequency to wavelength using this online RF calculator. A quarter wave transformer is used to match two transmission lines with different impedances. The Frequency from Wavelength calculator computes the RF frequency (ν) based on the wavelength (λ) and the speed of light (c). What is the wavelength of a radio wave (RF wave)? The wavelength of a radio wave depends on the frequency at which it travels. 361564_P_17Y. This is a required field. 65 figure, then look up the data sheet for the speed of. This calculates the wavelength if you know the frequency and wave velocity. The Number that follows "WR" is the width of the waveguide opening in mils, divided by 10. Is all that stitching shown in figure really necessary from an RF point of view? Probably not. 7/8 λ. EXAMPLE#1 (Doppler frequency calculation for moving reflector case): Speed of Wave source (m/sec) = 1000 , Operating Frequency (MHz) = 3000(i. RF Calculator for Frequency calculation. A few basic facts about waveguide: Here are Waveguide Equations & Fields. This can be easily calculated by hand or by using an online calculator. This everything RF calculator calculates the various parameters related to the design of a Whip Antenna. 5 Frequency of RF waves : Frequency of RF waves is the number of EM waves passing a given point in one second. r is the contribution from the RF components between the antenna and the receiver – Temperature of RF components • L r is the loss of input RF components. 3 is accepted only if it is larger than R is usually computed for the boresight. If the reflection coefficient (Γ) is known, then the VSWR. Featured Tools Trace Resistance Calculator This calculator determines the resistance of a microstrip trace. Depending on the operating frequencies and power levels, the dimension of the aperture should be smaller than 50and not greater. The ITU Radio Frequency to Wavelength conversion tool allows you to enter a frequency from 8. This speed can be calculated based on the frequency/wavelength of the wave and the Pulse Repetition Time. User assumes all risks for its use. Our RF calculators and converters will provide the figures you need for your radio frequency engineering needs. 4. Symbols. 5 with no velocity factor. MHz. 'm'. This calculator calculates the maximum range of a radar based on the power transmitted, system gain and receiver sensitivity. 7,506. TEM Wavelength Calculator. 96 m 5. e. Frequency in MHz:Distributed Inductance (L') For a coaxial cable, the inductance per unit length L' in henries per meter (H/m) is defined as. milli. The pulse repetition frequency (PRF) is the measure of the number of pulses per second of a repeating signal. Also note that the gain equation is optimized for small angles - see derivation of wavelength portion of equation [7]. RF calculations and conversions include metric-standard, link. ν = c λ The wavenumber is also a unit of frequency. NEW Version V2323, released on 31 May 2023, FREE DOWNLOAD, WinRFCalc is the best Windows RF calculator toolbox for EMC, RF and Radio engineers. The resonant frequency of a cavity can be calculated by using the following formula. This property is commonly used when referring to the longest wavelengths, the radio spectrum from a few Hz up to the THz range. The length of the dipole is usually one-half of the wavelength of the RF signals. This is a required field. To calculate the height above ground, you need to subtract the result from a line drawn directly between the tops of the two towers. Here is a list of some of the calculators in this app: Attenuator Calculators. h is Planck's constant which is equal to 6. With our tool, you need to enter the. com. The ITU Radio Frequency to Wavelength conversion tool allows you to enter a frequency from 8. 05 m, multiply by 39 and you have 80 inches. Most RF Coaxial Cables have an impedance of 50 ohms or 75 ohms. 25 mm/h for very light rain to over 50 mm/h for extreme rains. The length of the dipole is usually one-half of the wavelength of the RF signals. 3kHz -11. 847-592-6350; [email protected] Wavelength of RF waves : Distance covered by one complete cycle of the RF wave, as shown in Figure 1. To calculate the speed of sound in a medium, follow these steps: Find the sound's wavelength (λ) and frequency (f) in the medium. 04 gigahertz), respectively. - Microstrip Patch Antenna Calculator - Wavelength Calculator - RF Power Density and many more. 14 meters. Enter the values of operating frequency and relative dielectric constant then click on calculate to get the effective dielectric constant and guide wavelength for any slotline. Select whether a Velocity Factor applies. When electromagnetic radiation is incident on the. C = Speed of light. RF calculations and conversions include metric-standard, link. Operating Frequency. Waveguide Calculator (Rectangular) Pasternack's Waveguide Calculator provides the cutoff frequency, operating frequency range and closest waveguide size for a rectangular waveguide based on the custom inputted broad wall width. It only allows the propagation of microwave signals within a certain range of frequency. Frequency. $endgroup$ –Calculate the length of quarter wave antenna for transmission frequency Check Details Antenna calculator length quick dxzone excel xls spreadsheet checks elements trim really much simple way. For such an antenna, the near field is the region within a radius r ≪ λ, while the. 223 V = 223000 µV. Frequency to Wavelength Calculator. With this calculator you can calculate RF parameters in a radar range depending on: Frequency. Image formation in a lens takes place by the refraction of light at its two bounding surfaces. 6mm thickness and the connector is a SMA. This is a required field. Radiated Magnetic Field from a Loop Antenna (Low Frequency, Close Proximity). Description. Click Here To Download Product Brochure. What is Frequency? This calculator calculates wavelength in meters from the radio frequency (RF) entered in units of MHz. The formula used in the Far-Field Calculator is: d F = λ 2 ⋅ D 2 Example. This calculator can be used to determine the 1st through 15th harmonic of any fundamental frequency. The Wavelength from Frequency calculator computes the wavelength (λ) based on the RF frequency (ν) and the speed of light (c). For example, if you are making a PIN diode switch with two shunt diodes spaces 3/4. 7 MHz, or for a half-wavelength, 115. 6 mm. To calculate the speed of sound in a medium, follow these steps: Find the sound's wavelength (λ) and frequency (f) in the medium. D is the inside diameter of the coax cable shield,. 15 for the 40 meter band). 4/3 λ (Hentenna circ. = v2πf. The wide inside dimension in inches is the "xxx" part of WRxxx; ie, WR650 is 6. Choose a calculation to use the wavelength equation λ = v/f to. However, this can be automatically converted. Frequency. The Parabolic Reflector Antenna Calculator on everything RF is an online tool that assists engineers and designers in calculating the critical parameters of a parabolic reflector antenna. 7/8 λ. Enter the Frequency to be converted. To calculate the wavelength of a periodic oscillating motion, given the frequency, you first need to know the speed of the wave. Select the Frequency value's Dimension. Then, apply the formula: λ = v/f. 13,573. 19. Formula for Antenna Near Field & Far Field Distance Calculator. The dimensions of some of the quantities that appear in transmission line theory are discussed in Section. Coplanar Waveguide Calculator. Conversion Tables. If the medium in which the light (or radio wave) is traveling is something other than free space, the velocity factor of the medium can slow down the speed of light. Choose the velocity of the wave. Useful for identifying the frequency range of a particular radio band. where. f f = frequency. : 3. With this calculator you can calculate and verify RF levels on a Radar Target Simulation range. To maximize signal strength between the transmitter and receiver, the antenna installer needs to keep the obstruction-free direct transmission. The ITU Radio Frequency to Wavelength conversion tool allows you to enter a frequency from 8. Using the league table, you can see that the dB loss for 100m of LMR-600 coax at 50. Łucja Zaborowska, MD, PhD candidate. See drawings. 1 * 109 Hz), the wavelength = (3 * 108 m/sec) / (2. This can be easily calculated by hand or by using an online calculator. The spacing ( S) is determined. Noise Factor to Noise Figure Calculator. An alternative formula is:Radiofrequency (RF) electromagnetic radiation (EMR) is the transfer of energy by radio waves. If you have no particular preference within a given ham radio band, then simply enter its center frequency (i. Our website uses cookies. Radiation: • Electromagnetic wave (wavelength, frequency, period) • Propagation delay (distance vs. 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. The Wavelength from Frequency calculator computes the wavelength (λ) based on the RF frequency (ν) and the speed of light (c). Comments. This is a required field. TX Output Power and RX Sensitivity need to set up based on the radio device’s actual link parameters based on the data sheet. If you want to calculate the Frequency from Wavelength - Click here to use the Wavelength to Frequency Calculator. where: E is the energy of the photon. The band is sometimes subdivided into VHF-Lo (RF 2 - 6), and VHF-Hi (RF 7 - 13). This term is used in technical disciplines such as radar. As an RF signal propagates away from a transmitter the power density reduces conserving the power in the EM wave. In any other medium, the propagation speed is slower and at the same frequency, the wavelength becomes shorter. The relation of frequency and wavelength in a radio wave traveling in vacuum or air is. . The resonant frequency of an LC Circuit is the frequency at which the inductive reactance and capacitive reactance of the LC circuit are equal. Watt To dBm Calculator. Here you can calculate the period with respect to the amplitude-phase shift period calculator in a span of seconds. Yes - Enter the Velocity Factor or, select one. A Rectangular Waveguide is a conducting cylinder of rectangular cross-section used to guide the propagation of waves. This can be set to zero, but the calculated loss will not include conductor losses. microwave ovens work at a wavelength of about 10 cm. Doppler effect is widely used in medicine – it allows us to measure the blood flow in arteries and veins, perform ultrasound, and it also has a great purpose when dealing with how to calculate cardiac output with echocardiography doppler. When the waveguide radius a is constant, the order of the modes remains unchanged. S. Here is a nice wavelength calculator I just found to generate the table above. Suppose your network was a short circuit, the left "corner" of the Smith Chart. Canadian Radio Frequency Allocations. The Friis transmission equation gives the power received by an antenna from another antenna that is transmitting a known amount of power at a distance under ideal conditions. d is the diameter of the inner conductor of the coax cable; units of D and d must be the same,. The substrate parameters (ε r and h) and the frequency of interest are required. 2GHz]Signal’s power level lower than 1 mW has negative dBm values, and the signals stronger than 1 mW have positive dBm values. This Doppler effect calculator is a simple tool to determine the apparent frequency or observed frequency of a wave when its source or the receiver is in motion: Enter the emitted frequency value. The length of a half-wavelength dipole can be calculated by the given formula: L =. Antennas, Unit-Conversions, VSWR, RF power, DSP, EMC and much more RF related topics. You can also use this tool as a frequency calculator. All About Circuits is the largest online electrical engineering communities in the world with over 700K engineers, who collaborate every day to innovate, design, and create. c = Speed of Light (299,792,458 m/s) f = Frequency. The unit of radio frequency is Hertz (Hz) i. Stack Exchange Network. ε 0 = 8. Frequency: Frequency at which the stripline is analyzed or. One for feet and the other for meters. 96, f represents the frequency in MHz, 0. 1, makes the argument that a circuit with resistors, inductors, and capacitors is a good model for a transmission line. To achieve a matching impedance of 50 Ohm, the ground plane elements are bent down at an angle of 45 degrees and no matching stubs or balans are needed. - Reflection Attenuator Calculator. Hz kHz MHz GHz. For electrically large antennas there. All About Circuits is the largest online electrical engineering communities in the world with over 700K engineers, who collaborate every day to innovate, design, and create. Understanding Frequency and Wavelength. Calculate. 185 megahertz is channel 19, the highway channel, of the Citizens Band Radio Service. )It may NOT be what we had in mind. A microstrip is a type of transmission line in which a strip of a conducting material like copper is mounted on a dielectric material and routed to a ground plane. This calculator uses the following formulas for converting the values between the VSWR, return loss, reflection coefficient, and mismatch loss. 7, 494, and 983. dBm To Watt Calculator. wavelength (in meters) = 300 / frequency (in MHz) For example, a frequency of 14. Pasternack waveguides are structures for guiding electromagnetic waves, often called a waveguide transmission line. Adding one quarter-wavelength moves you 180 degrees to the right side of the chart, to an open circuit. Noise Temperature to Noise Figure Converter. Cutoff Frequency Calculator. εr (relative permittivity) This is a required field. In the absence of obstacles and without atmospheric attenuation the total power passing through the surface of a sphere centered on a transmitter is equal to the power transmitted. To fully understand the results obtained by this calculator, please take a few minutes to read the. It calculates power at the receiver and path loss. For example, 100 ppm of 100 MHz represents a variation in frequency of 10 kHz. You may use the formula: Wavelength = c/f, where: c - The speed of light equal to 299,792,458 m/s; and; f - The frequency of the antenna. Yes - Enter the Velocity Factor or, select one. Skin Depth Calculator. IEEE defines it as "The loss between two isotropic radiators in free space, expressed as a power ratio. Thickness: Thickness of the stripline conductor. The corresponding wavelength is called the EMI shield wavelength. a, b, h = Cavity width, length, height in mm/cm/Inch. Scroll to View . Most of the time I ditch the equations and use experimentation when it comes to RF because it would take longer to calculate what is happening with RF than to actually test it. The benefit of expressing signal strength (power) in dBm is: we can express both very large and very small power values (W) in a short range of number. Operating above the cut-off frequency that results in interference in signal propagation. This impedance is used to calculate the depth ( D) into the patch antenna. × 10 −12 F/m is the. 8 in) = 62. The wavelength is the distance covered by one complete cycle of the electromagnetic wave, while the frequency is the number of electromagnetic waves passing a given point in one second. This is roughly between the upper limit of audio frequencies and the lower limit of infrared frequencies. Examples of TEM: Free space, Coax, Stripline, Waveguide. The beamwidth will vary given a number of different factors such as the antenna type, design, orientation and radio frequency. According to WatElectronics "Wireless Radio frequency is any of the electromagnetic wave frequencies around 3 kHz-300 GHz". 4 *. Wire Antenna Calculator. The circular waveguide supports both TE (transverse electric) and TM (transverse magnetic) modes. The wavelengths of the UHF are 1 decimeter to 1 meter and thus it is comparable to the sizes of buildings, cars, and trees. This calculator utilises the diameter of the reflector and the operating frequency to calculate critical antenna characteristics such as gain, HPBW, and. The formula to calculate the 1/4 wavelength of an antenna for a specific frequency is approximately: Wavelength (λ) = Speed of Light (c) / Frequency (f). The frequency and the wavelength are intimately related, so the operating frequency has just as much to do with the via spacing as the wavelength does. Calculators: • Wavelength • Free space path loss • Attenuators • Link budget • Resonance • VSWR • Reflection coefficient • Return loss •. Let's look at an example.