noise figure calculator. This causes the noise transfer function to have a nonflat shape that is notched lower over a narrow band of interest, smaller than the Nyquist. noise figure calculator

 
 This causes the noise transfer function to have a nonflat shape that is notched lower over a narrow band of interest, smaller than the Nyquistnoise figure calculator  In practice however the noise figure can be designed to be 8 dB or less

the input noise spectral density of the device, it is a simple matter to plug it into Equation 2 and calculate F. The total noise factor is given as. The most important noise-related metric is the . You can use equations to calculate power, gain, and power added efficiency. To calculate the number of revolutions per minute, use these equations: For HAWT: RPM = 60 * v * TSR / (π * 2 * L) For VAWT: RPM = 60 * v * TSR / (π * D) Source: Wind Turbine Calculator This wind turbine calculator is a comprehensive tool for determining the power output, revenue, and torque of either a. Stages can be easily inserted, removed or temporarily muted. It is measured in volts squared per Hertz or equivalently in Volts per root Hertz. Calculators > Decibel Calculator Decibel Calculator. 2. Noise figure (NF) The signal source has a certain SNR dB. 9 Inches [22. Compute nonlinear effects such as output power, IP2, NF, and SNR using. In order to measure noise figure, the HP 85719A works in conjunction with the HP 346B noise source and HP 87405A preamplifier. Calculate the noise level at your ear using Sensear's Hearing Protection Calculator to make sure you are meeting OSHA-established permissible noise exposure limits. Noise-source ENR or power-meter uncertainty. 58) * 226 510. The number of stages can be varied up to a maximum of 20. 20 MHz – 6 GHz; 30 MHz – 512 MHz; 500 MHz – 2500 MHz; 2 GHz – 6 GHz;A (hypothetical) noiseless amplifier would have a noise factor of 1, corresponding to a noise figure of 0 dB. This noise is constant for a given system impedance and comes out to −174 dBm/Hz at room temperature. 4 nV rms. 76 dB, where N is the ADC’s resolution. This concept of a noise figure can also be applied to optical amplifiers 1 5, but it should be noted that not all definitions in the literature are the same. Stage: NF (dB) Gain (dB) Cascaded NF Cascaded Gain *Note. 4. 23 × 3. Figure 2 shows a noise analysis diagram for an inverting op amp amplifier with the noise sources identified. Assume that the input noise temperature of each. Classified by their potential to reduce noise in decibels (dB), a term used to categorize the power or density of sound, hearing. The NoiseMeters decibel calculator can be used to carry out addition and. So, a piece of coax with 4 dB of loss has a noise figure of 4 dB. To calculate the level of exposure at the ear, first, enter the NRR number as listed on the hearing protective devices box or paperwork that came with the device. 000002) or approximately 62 dB. The decibel calculator can be used to combine the levels of up to ten incoherent (noncoherent). This result can be generalized for a system. F SNR SNR S N GS GN N N N I O I I I IA A I == × ×+ =+ 1 . Shot noise also occurs in photon counting in optical devices,. Noise generated by Fans - Blade Pass Frequency (BPF) TheBlade Pass Frequency noise generated by a fan can be very intense and varies with the number of blades and the rotation velocity. The download bit rate is 39 Mbps and the upload bit rate is 5. Subtract KTB from the normalized Nyquist band noise power to determine the ADC effective noise figure. Calculate the required attenuation. Noise Figure . Exposure times can be up to 24 hours at each location with a limit of 24 hours on the total exposure time. Calculators. Since the drain current is injected into the input, it adds noise in shunt with the input noise current F > 1+ i2 d i2 s A. In no event will Qorvo be liable to any user of these tools for any loss or. Learn More. In practice however the noise figure can be designed to be 8 dB or less. This relative rise in noise level is expressed by the amplifier noise figure. The noise temperature is directly proportional to the temperature in degrees Kelvin. To get the total noise, we must add the 1/f noise and the broadband noise together. It is possible to relate the 1/f noise measured in the 0. simple inverting circuit (Figure 2) and the corresponding noise model (Figure 3). In electronics shot noise originates from the discrete nature of electric charge. Use the EM Talk noise figure calculator to determine the overall noise figure for a cascaded N-stage amplifier/system. individual noise sources and the perceived sound level at a. Since i2 d flows partly into. Featured Examples. It can alternately be defined as a signal that produces a signal-to-noise ratio of a given value m at the output. 4) 9. Exposed equations, instrument specifications, statistics. This free online conversion is focused on Noise Figure. Multiply the better ear by 5 (to weight it more heavily). No need to download an excel sheet to do your noise figure calculations! How To Use First, select the number of stages for your cascade. As a test, 10 * log (2) should give an answer of +3 dB. Enter the prefix, symbol and value of the input and output impedances and get the noise figure in decibels (dB) and the noise and gain in dBm. To calculate the level at the ear, first measure the worker's noise exposure, either in dB(A) or dB(C). Find the noise figure of the following wireless receiver front end, shown in Figure 5. . The Signal-to-Noise Ratio (SNR) and Dynamic Range (DR) are two common parameters used to specify the electrical performance of a spectrometer. This application note is specific to instruments that use the Y-factor method for noise figure measurement. To. Employee works for 2. Signal-to-noise ratio ( SNR or S/N) is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. • calculate system noise temperature T RX T L LT LNA T sys)280 (1. In addition, the filter has a loss of 1 dB. The same is true when the number of gain stages increases. Where ENR is the excess noise ratio which can be found in a table on the noise source itself or on its datasheet. Exposure times can be up to 24 hours at each location with a limit of 24 hours on the total exposure time. Note that for quasi-three-level laser gain media, this ASE effect is stronger than for four-level media. Key Definitions. Next, determine the noise floor (dB). A. Typical signal and noise levels vs. However, this is not possible. Cascaded Network: A receiver systems usually consists of a number of passive or active elements connected in series, each element is defined separately in terms of the gain (greater than 1 or less. Link Budget is a way of quantifying a communication link's performance while accounting for the system's power, gains, and losses for both the transmitter (Tx) and receiver (Rx). Antenna Separation (R). 1/f noise is not really a stationary process (since the more we wait the more 1/f noise we see) { it is usually approximated by a stationary process with 1/f psd within a frequency range [fmin;fmax] fmin is determined by the circuit observation time" fmax is where 1/f noise psd is su ciently lower than thermal/shot noise EE 392B: Temporal. You can convert phase noise to jitter (rms) for a specified offset frequency range, plot phase noise data and export results as a png, csv or PDF file. Mainly noise figure is used to verify the performance of the receiver. These applications run in your browser, so there is no installation necessary. Example of a time domain plot from a HB simulation. Here 'G' refers to antenna gain and T refers to system noise temperature. For modern communication standards that use orthogonal frequency domain modulation (OFDM), the phase noise should be integrated from starting at about 10%. Both vector and scalar noise calibrations are supported, as well as characterization of the noise receiver using a noise source or power meter. Since it is represented in a. Noise Factor is the measure of degradation of the signal to noise ratio in a device. Background equations are presented for each step of the calculation. In signal theory, the noise floor is the measure of the signal created from the sum of all the noise sources and unwanted signals within a measurement system, where noise is defined as any signal other than the one being. Since we know that, we can calculate the total noise power over a given bandwidth by calculating the total area under S X (f) in that frequency band. vi In modern digital sensors, these classical factors have been joined by a third, theGain and noise figure are given as ratios. Noise Figure is the amount of noise that the DUT is adding in a 50 ohm test setup. These amplifiers pass white noise with a cutoff frequency of fc = 1. Noise Figure Uncertainty Calculator. -163. The accuracy of the noise measurement is directly related to the second-stage noise figure of the noise receiver, the lower the better. Characteristics of noise sources are presented to help the designer make informed decisions when designing for noise. We can describe the exact relationship between the sound level and distance using the sound attenuation formula. The VectorStar Noise Figure Uncertainty Calculator is a standalone program used to provide the user a tool for easily determining measurement uncertainty while using the VectorStar Noise Figure Measurement – Option 41; the calculator will operate on the desktop of VectorStar or an external PC and is an executable launched from the program. Stated another way, noise figure quantifies how much a DUT(Figure 6). Optional tolerance analysis of all gain, noise figure and P1dB for each. Engineers use the formula to optimize the noise performance of a system. It indicates the level of noise reduction provided by these devices in decibels (dB). Following equation or formula is used for antenna G/T ratio calculator. The Noise Factor is the ratio of the signal-to-noise ratio at the input to the signal-to-noise ratio at the output SNRin SNRout SNR in SNR out. Analysis of thermal noise as it moves through the chain (noise power and signal/noise ratio are calculated). 6. Advertise with us;. Calculate. Other products, however, may be used with the techniques discussed in this. Stage 1 includes a Directional Coupler (-1 dB) and a Bandpass Filter (-1. Various features of Keysight Technologies products are mentioned as illustrative examples of the newest generation of noise figure analyzers and noise sources. • Personnel information. Hearing protection calculators. Now turn the sound source off and measure in the same location just the background noise. The sensitivity is as follows: Sensitivity=10×log10 (kTB)+NF+C⁄N. M. Noise Figure Uncertainty Calculator. Figure 4. These charts calculate positive and negative magnitudes of noise based on noise characterization of waves due to power difference of two intensities. Jul 9, 2009. 38 10-23 J/K, Boltzmann constant. I = ( Δ p ) 2 2 ρ v w , 14. A Javascript-based calculator, based on the introduced model, has been developed and madePhoton noise simulation. Download today. Details on noise measurement by a LISN is provided in a later session of the document Section 6. Noise temperature (T) = 290 * (10^(NF/10)-1) (Kelvin) While we're on the subject, Noise figure (NF) = 10 * log (noise factor) dB. Use the following equation to calculate the phase noise of a phase-locked oscillator based on the phase noise of the reference oscillator it is locked to: Phase NoisePLL ( ) = Phase NoiseRef + 20*log (fPLL/fRef) {dBc/Hz} Be aware that the equation is theoretical and that a real world PLL will add some of its own intrinsic components to the. 1. Figure 3. Below is a handy equation to calculate the Noise Figure of a circuitry using noise source. Calculate the input signal-to-noise ratio S/N i from the ratio of P si and P ni (2-16). The overall. 57 ⋅ (20000 Hz - 20 Hz)) = 1. Wavelength Calculator. Dosimeters average noise levels over time and calculate a noise dose. In it we will calculate derivatives of Voronoi noise. The Radar Equation Calculator app solves the basic radar equation for monostatic or bistatic radar systems. Feel free to insert your own values. Everyone and their little brother has created an Excel spreadsheet for performing Cascade. G/T ratio is referred as figure of merit of the antenna system. Version 10. This noise arises due to the quantized nature of charge. Even without a full analysis, one can see that using NSD as the specification to determine the in-band usable dynamic range is particularly helpful for Σ- modulators. ELIMINATION: The elimination of a noise source may be impractical or impossible to achieve, whether emanating from within or outside the structure. Noise Type=jitter: The Noise Type=jitter option only calculates PM jitter for both driven circuits and oscillators. Here is how the Noise Figure calculation can be explained with given input values -> 13 = 390/30. Noise Power Parameters show the amount of noise coming out of the DUT in a 50 ohm test setup. 7%. Rental. 10 -12 represents the intensity of a 0 decibel sound, so by comparing your intensity value to this, you're essentially finding its relationship to this base value. The Noise Figure (dB) is 10⋅log10(Noise Factor) 10 ⋅ log 10 ( Noise Factor). Calculate the output signal-to-noise ratio S/N o from the ratio of P so and P no (2-19). 00, July 2022 4 Rohde & Schwarz Noise Figure Measurement Application Specifications The specifications of the R&S®Fxx-K30 noise figure measurement application are based on the data sheet specifications of: • R&S®FSW signal and spectrum analyzer • R&S®FSWP phase noise analyzer • R&S®FSMR3000 measuring receiver •. Expressed in dB, the. The OSHA NRR method is as follows:The link budget is an impotant value that enables engineers to design systems based on the required sensitivity of a receiver at a particular distance. Friis's formula is used to calculate the total noise factor of a cascade of stages, each with its own noise factor and power gain (assuming that the impedances are matched at each stage). where . Practical phase-noise measurement setup. Specially, A-weighting (dB (A), dBA) is used in almost measurement, which. The calculations are based on the paper of Bar-Giora Goldberg, "The Effects of Clock Jitter on Data. The noise figure is a bit trickier than gain to cascade through a block diagram and requires that noise figure (NF) in dB be converted to noise factor (F) and run through Friis’ formula for noise factor (F) 4. Using this equation, we can calculate the ADA4622-2 total rms noise with a simple 1 kHz, low-pass RC filter on the output to be 495. Noise temperature is measured in units called. This tutorial is made with Unity 2020. RF calculations and conversions include metric-standard, link. The SNR ratio of more than 1:1 (greater than 0 dB) indicates more signal power. To. Blocker or Jammer Signal Interference channel LNA Consider the input spectrum of a. These are the ways to calculate the signal to noise. Noise Figure (NF) is a measure of how much a device degrades the Signal to Noise Ratio (SNR), with lower values indicating better performance. We also need to transfer NF’s into linear values (Noise Factors F_1 through F_ {14}) before we are able to Calculate the Cascade Noise Figure. Decibel, dB. 1 Definition of Noise Figure The noise figure of a device provides a quantifiable measure of the noise that a device under test (DUT) adds to a signal as that signal passes through it. T ref T r e f = reference temperature. Reset. Minimum detectable signal. Spectrum analyzer accuracy may not be as good as purpose-built noise figure meters but the spectrum analyzer is more than adequate in ordinary radio work. Antenna Gain to Noise temperature ratio i. systems have provisions to measure noise and noise-like signals (figure 6-1). The EIRP can take into account the losses in transmission line. Signal-to-Noise Ratio (SNR) is the ratio of the signal power to noise power. The noise figure number, displayed in decibels (dB), represents the performance by which an amplifier or RF receiver can be measured. Receiver Signal Chain (a) LNA: The RF signal received from the antenna is fed to the LNA. 569 × 1 0 − 9 V. The total noise factor can then be used to calculate the total noise figure. A detailed discussion of allThe noise factor is expressed as a dimensionless ratio. The maximum Noise Figure of the receiver when is given the required Sensitivity and the required Bandwidth: Receiver_Noise_Figure[dB] = 174 + Receiver_Sensitivity[dBm] – 10*LOG(BW[Hz]) – SNR[dB] As can be seen from the formula above, narrow Bandwidth and smaller SNR will relax the required receiver Noise Figure requirements. Once finished filling out all the fields, click Calculate to preform the calculation. Cart. Assume a technician works in a noise enclosure booth with a noise exposure of less than 70 dBA. Figure 2 shows a noise analysis diagram for an inverting op amp amplifier with the noise sources identified. The calculator offers four different calculation types, each of which has a unique formula that you must use to calculate the noise value based on your inputs. noise. Figure 2 shows a noise analysis diagram for an inverting op amp amplifier with the noise sources identified. The Noise Figure can be calculated by expressing noise factor in decibels (dB). gain-setting resistor values, source resistance, bandwidth, etc. F SNR SNR S N GS GN N N N I O I I I IA A I == × ×+ =+ 1 . A minimum detectable signal is a signal at the input of a system whose power allows it to be detected over the background electronic noise of the detector system. Noise exposure calculator. These formulae are only valid when the input termination is at standard noise temperature T0 = 290 K, although in practice small differences in temperature do not significantly affect the values. This right-hand circular polarized (RHCP) antenna filters and amplifies GNSS L1, GLONASS G1, and BeiDou B1 global positioning signals received from satellite constellations. The point target radar range equation estimates the power at the input to the receiver for a target of a given radar cross section at a specified range. Level is above the criterion level. Just enter the value and click calculate. Noise Power Parameters show the amount of noise coming out of the DUT in a 50 ohm test setup. The noise figure number, displayed in decibels (dB), represents the performance by which an amplifier or RF receiver can be measured. It accounts for losses that apply to the signal and not the noise. 6 = 54. First, we will discuss spectrum analyzer sensitivity in terms of its noise floor and then go This distance attenuation calculator is a tool that lets you analyze how the sound propagates in the air. In the case of using a voltmeter, the measured voltage and the circuit’s load are used to calculate noise power. An electronic system's noise figure is the ratio of the signal-to-noise at the input to that of the output. NOISE • noise voltage • independent of frequency, “white” noise. The Friis path loss formula. Our RF calculators and converters will provide the figures you need for your radio frequency engineering needs. As mentioned previously, our sound absorption coefficient calculator allows three different methods to. Pad Attenuator (Pi, Tee, Bridged-Tee) Calculator pop-up . To find the clock jitter, enter the clock frequency and phase noise, and set the integration limits from (1KHz) to (50MHz), assuming contribution from outside this bandwidth is negligible. 4K 10 1 50 (1 0. This is why a low-noise amplifier (LNA) is the first active device in a communications system. The noise factor and gain of the LNA and mixer are also shown in the figure. The TMC261 from mmTron is a Power Amplifier MMIC that operates from 17. What we really want to know is the readout noise in electrons. The computations can be performed with the uncertainty calculator. With gain measurements of the DUT, these noise power parameters are used to calculate noise figure. The Standard Deviation. Noise Conversion Calculator. This formula is derived from the definition of Noise factor F. Noise Figure (NF) = 10 * log (noise factor) dB. SNR (Signal-to-noise ratio) is a ratio of signal power level to the noise power level. -163. Cascade analysis is a simple yet powerful tool for analyzing system performance. Noise Figure • Noise Figure Figure 1-2. L is a term included to account for all losses that must be considered when using the radar range equation. The purpose of the present paper is to present a consistent approach to modeling the noise figure of optical amplifiers and other optical components and to review noise figure measurement. If you want a weighted (e. Stripline Calculator. It goes to 0 at 0°K. 1 Noise Figure. This application note describes in detail the steps required to make a noise figure measurement on a spectrum analyzer using the “Y Factor” technique. On-Demand Webinars. 45% and 99. Example: Find the dB noise power of a pump from a meter reading of 87 dB pressure taken 9 feet from the pump. The result is 78. then multiply by the bandwidth to get the total amount of noise power:Pasternack's Friis Transmission Equation Calculator with formula will calculate the received power from an antenna at some distance given a transmission frequency and antenna gains. This calculator will be used in the examples to follow. In this chapter, let us calculate Signal to Noise Ratios and Figure of Merits of various modulated waves, which are demodulated at the receiver. The Y Factor Technique for Noise Figure Measurements. When you think about 'Noise', usually you think noise is coming from somewhere outside. The Noise Figure is noise factor expressed in decibels (dB). Noise Temperature K. M. 888 206 4377 Email. everything RF has the largest selection of online calculators for the RF and Microwave Industry. Overview. Noise exposure time. The Cascaded Noise Figure formula and calculator help engineers analyze and design these systems while considering noise performance. 85 Mbps, significantly less. The Noise Temperature (K) is 290⋅. NF in ADCs There are a couple of ways to go about calculating the input noise spectral density of an ADC, but using the SNR specification is easy. If no LNA is used, set the value to zero. Luis Hoyos. In this case, we only need to calculate the part of the output noise that stems from the source impedance N o (source) and the part that is produced by the circuit N o (added). 5 bits (80,000 noise-free counts). An 85 dBA 8-hour TWA equals 50%. Noise Figure for Inductive Degen Cgs gmvgs ro + vgs − Rg id v2 R Rg s Vs Ls Lg i o It’s fairly easy to calculate the noise for the case with inductive degeneration. Third Order Filters A third order filter ideally yields an attenuation of 18 dB perSound Level and Noise Exposure Calculators. The sound pressure level, or SPL, is simply the measure of sound pressure with reference to the human hearing threshold. G_ {1-1} through G_ {1-14} are total gains in dB at the output of each stage referred to the front-end input. Various features of Keysight Technologies products are mentioned as illustrative examples of the newest generation of noise figure analyzers and noise sources. systems have provisions to measure noise and noise-like signals (figure 6-1). In the case of the first two stages (preselector and amplifier), the noise figure (NF) can simply be added in dB as shown in Figure 2. For example, G_ {1-7} is the total gain from the front-end input to the output of stage 7. 17/20 – pThis figure depends on receiver self noise, bandwidth, and temperature, so that results way down to -110 dBm and lower can also be achieved, either by adding cost to lower receiver self noise, or. The most important noise-related metric is the . Antenna noise figure is a way of expressing the noise power produced by the antenna (presumably when it's pointing at the cold sky). The following measurement guidelines. For a noiseless receiver, N i = 0, noise factor F=1 and NF=0 dB. 7 GHz. Cascade Calculator. Niknejad University of California, Berkeley EECS 142 Lecture 11 p. Two effects are observed. Denoting the noise power input to the amplifier as , and denoting the signal power input to the amplifier as , the input signal-to-noise power ratio is . Denoting the noise power input to the amplifier as , and denoting the signal power input to the amplifier as , the input signal-to-noise power ratio is . Click here to go to our page on noise figure (includes a gain/NF cascade example). First, determine the overall noise figure (dB). Noise Figure Calculator Calculate noise figure, gain, and noise temperature for a N-Stage cascade device. It is the output power when a signal is concentrated into a smaller area by the Antenna. F SNR SNR I O = . Signal-to-Noise Ratio (SNR) • Considering the presence of noise, the important parameter for detection is the signal-to-noise ratio (SNR) • Factors have been added for processing gain Gp and loss L • Most radars are designed so that • At this point we will consider only two noise sources: 1. When paired with Keysight’s smart devices, the unce. 12/29. This free online conversion is focused on Noise Figure. To convert the spectral density v~ v ~ (in nV/√Hz) to a voltage (in V RMS ), you need to multiply it by the square root of the bandwidth: vRMS = v~ ⋅ Δf−−−√ v R M S = v ~ ⋅ Δ f. 1 to 10 Hz peak-to-peak noise scope photo on the right-hand V. This is the fourth tutorial in a series about pseudorandom surfaces. Stage 3 is a resistor attenuator, G3 = −3dB and NF3 = 3dB. Next, gather the formula from above = RS = OSF + NF. Rx Cable Cable Loss [dB] Loss in dB given as a positive value Receiver (spectrum analyzer) DANL [dBm/Hz] Displayed Average Noise Level. Bridged Tee Attenuator Calculator. Below figures show how to add the individual level to estimate total noise level. On the right is a screen shot of a calculator that was created to make quick work of predicting noise using these equations. This relative rise in noise level is expressed by the amplifier noise figure. 09) = 3. Interpret the Result : The calculated SNR value represents the quality of the signal. The lower noise figure number, the better. N F = 10log10 [ T noise T ref + 1] N F = 10 l o g 10 [ T n o i s e T r e f + 1] Where: N F N F = noise figure. Here is how the Drain Current of Low Noise Amplifier calculation can be explained with given input values -> 11. There are 4 stages in section 1, and 2 stages are blank. Unless a device is working at absolute temperate zero (-273 degree in celcius), there always are such a noise generated by an object itself. Noise temperature is a representation of noise in terms of the temperature. The number of stages can range from 2 to 30. ADIsimRF is an easy-to-use RF signal chain calculator. It provides an output P1dB of 1. Enter the prefix, symbol and value of the input and output impedances and get the noise figure in. This equation defines the signal power in dB·Watts that is. It indicates how much noise the receiver electronics add to the thermal noise. Following equation or formula is used for antenna G/T ratio calculator. The further away you are from the sound source, the lower the perceived sound intensity. As mentioned earlier, the NRR on an HPD can’t be taken at face value as it only indicates the number of decibels the device can attenuate under ideal lab conditions. This step is necessary because the thermal. Noise Figure The Noise Figure (NF) of an amplifier is a block (e. It calculates power at the receiver and path loss. 85 equating to 290°K as per IEEE recommendations. Directional Coupler Calculator. This provides a more accurate depiction of the health of the wireless signals. If your circuit has 1-pole filters, for instance, the total noise would then be. Because I sc = -I s + I n +V n Y s, it follows that the mean square of I sc is given by equation 20: Because noise from the source and noise from the two-port network are uncorrelated: and equation 20 reduces to: Figure 7 shows the single sideband phase noise of two leading synthesizer candidates for this signal chain. This noise model lets you calculate the amplifier noise figure. Newsletter. Cisco Meraki Access Points reference the Signal to Noise Ratio as the indication for the quality of the wireless connection. Here are the results from an Internet speed test from my home laptop: The latency (also called the ping rate) was just 18 ms. NOISE FIGURE CALCULATOR. Bottom, fromThe Y-factor method simplifies noise figure measurements by allowing the use of variable attenuators in place of a calibrated power meter. Figure 3. How to calculate Noise Figure using this online calculator? To use this online calculator for Noise Figure, enter Maximum Possible S/N Ratio (SNm) & Actual S/N Ratio at Output (SNout) and hit the calculate button. 715 = (2. Example wireless receiver from end system. Calculating the Noise Figure in an Example Circuit. Cascade Calculator. This is explained in detail in Noise Concepts. Appendix A to § 1910. and then click the calculate bar, to get the calculated sum. The basic formulae are: Noise temperature (T) = 290 * (10^ (Noise Figure/10)-1) K. Sound levels are generally expressed in decibels, which are logarithmic and so cannot be manipulated without being converted back to a linear scale.