• This is done by using a pre-emphasis circuit and is used at the … 900 KHz, 888 KHz, 12 KHz b. What does the name "Black Widow" mean in the MCU? View Lecture No 30.pdf from ELECTRICAL 1909 at Institute of Space Technology, Islamabad. 5.1 Spectrum and Bandwidth 5.1 Spectrum and Bandwidth We know s (t) = A c n. = ∞ Spectrum and Bandwidth 5.1 Spectrum and Bandwidth We … Differences between UART receiver STOP bit implementations. For communications purposes less bandwidth is used. Why the corresponding FM signal is of finite duration? ANSWER: (a) Bandwidth of FM signal. Amplitude Modulation(AM) is the modulation technique in which carrier amplitude varies based onanalog baseband information signal to be transmitted using wireless device.one of the application ofamplitude modulation is radio. Clearly mark the transmission BW. Making statements based on opinion; back them up with references or personal experience. We have seen the block diagram of NBFM modulator at the beginning of this chapter. The transition width of LPF defines the sharpness of our filter, smaller the transition width greater the CPU time consumed for doing calculations. ), 2. See the answer. A WBFM signal has theoritically infinite bandwidth. Write the expression of theoretical bandwidth for WBFM 10 (c) Determine the bandwidth of an FM signal, if the maximum value of the frequency deviation ∆f is fixed at 75kHz for commercial FM broadcasting by radio and modulationfrequency is W= 15 kHz. – b >> 1: wideband FM, WBFM • Bandwidth, BW = 2(D+1)W, or BW = 2(b+1)f m 10/14/08 7 you can also transmit sound in the available bandwidth. Each carrier is modulated by a signal with a 5 kHz bandwidth. Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.. Visit Stack Exchange (Hint: Find Jn (B) Using Matlab) C. Plot The Spectrum Of WBFM Signal Using Matlab. In analog frequency modulation, such as radio broadcasting, of an audio signal representing voice or music, the instantaneous frequency deviation, i.e. 1; More than 1; Infinity; None of these; Answer – (3) 26. Signal to noise ratio c. Modulation index d. Noise figure. The no. You can redesign the specs in order to transmit at much higher frame rates. Replace a color in image with hatchfilling. IF frequency for FM receiver is. The maximum permissible deviation is 75 kHz and it is used in the entertainment broadcasting applications such as FM radio, TV etc. (Hint: find Jn (B) using Matlab) c. Plot the spectrum of WBFM signal using Matlab. This block diagram contains mainly two stages. Each year thousands of aspirants appear for GATE. Only quadrature detector; Only PLL; Both (1) and (2) Diode; Answer – (3) 27. To learn more, see our tips on writing great answers. Or maybe I'm missing something? Frequency modulation (FM) is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave. Is there interference from the sideband? Edit: Actually, there are two main questions here: 1. Each parameter has its own formula. . Inferior to AM; Superior to AM; Same as AM; Superior to WBFM; Answer – (2) 28. Facebook : https://www.facebook.com/GateExcellenceOfficial#Bandwidth\u0026PowerinWBFM #GateEC #AnalogCommunication 7) The ratio of maximum peak frequency deviation and the maximum modulating signal frequency is termed as. Wideband FM (WBFM) Now we determine the spectrum of the single tone FM signal for an arbitrary value of the modulation index E ^ ` ^ ` ^ ` envelope of FM signal. If the … Since LPF cutoff frequency is measured for only one side of the bandwidth, we set the cutoff frequency to 100 KHz. How to model a generic low frequency signal? • Therefore, the high frequency component which have low SNR are boosted or emphasized prior to the transmission of the signal. 1.7 Power and Bandwidth of FM Signals In the previous section we saw that a single tone modulated FM signal has an in–nite number of sideband components and hence the FM spectrum seems to have in–nite spectrum. Website: https://www.gateexcellence.com2. Problem 2 Bandwidth of a FM Signal (10 points) A 10 MHz carrier signal is frequency modulated by a sinusoidal signal of unity amplitude and with a FM frequency deviation constant k f = 10 Hz/V. What is the bandwidth of ϕ FM(t)? Superior to WBFM; Answer – (2) 28. After that it's stated that "The FM signal for $\hat{m}(t)$ consists of a sequence of such constant frequency sinusoidal pulses of duration $T = 1/2B$ corresponding to various cells of $\hat{m}(t)$". The Armstrong’s technique is … d. All of the above . Problem 1 (WBFM) Given fc a. As we have already shown, the bandwidth of a FM signal may be predicted using: BW = 2 (b + 1 ) f m. where b is the modulation index and f m is the maximum modulating frequency used. Thus, in WBFM, the value of m f is greater than unity and in Equation (2), unity can he ignored in comparison with m f approximate the bandwidth to: B WBFM = 2m f f m-----(8) Are new stars less pure as generations goes by? When choosing a cat, how to determine temperament and personality and decide on a good fit? MathJax reference. ANSWER: (b) Deviation ratio. Can concepts like "critical damping" or "resonant frequency" be applied to more complex systems than just a spring and damper in parallel? Efficiency. Bandwidth of FM signal b. Using photos obtained from academic homepages in a research seminar talk. In amplitude modulation, the amplitude of the carrier varies. The carrier frequencies start at 88.1 MHz and are separated by 200 KHz intervals. Signal Processing Stack Exchange is a question and answer site for practitioners of the art and science of signal, image and video processing. Determine the approximate bandwidth of the WBFM wave, using Carson's rule b. Bandwidth of VSB-SC is 25% higher than SSB-SC. ∑ [ ] ∞ =−∞ = − − + + + n n F c m c m c FM J f f nf f f nf A S f ( ) ( … A 100 MHz carrier signal is frequency modulated by a sinusoidal signal of 75 kHz, such that the frequenc7 deviation is f= 50 kHz. • The spectrum of this signal is: • This expression shows that the FM signal’s spectrum is made up of an infinite number of impulses at frequencies f = f c+nf m. • Therefore, theoretically, this WBFM signal has infinite bandwidth. Why did Churchill become the PM of Britain during WWII instead of Lord Halifax? An Elementary Discriminator Bandpass Filter f 0 = c elop ve … NBFM is. Use MathJax to format equations. Each year thousands of aspirants appear for GATE. 894 KHz, 884 KHz, 12 KHz c. 894 KHz, 888 KHz, 6 KHz In analog frequency modulation, such as radio broadcasting, of an audio signal representing voice or music, the instantaneous frequency deviation, i.e. The bandwidth of an FM system is limited by Carson's rule, but is still much higher, especially in WBFM. It is possible to send the data much faster by using more bandwidth. Spectrum of the WBFM signal when m(t) = A mcos2πf mt. Question: Problem 1 (WBFM) Given Fc = 200 Hz, Ac = 1, Kg = 1, M(t) = 5 Cos(10nt) A. View Answer: Answer: Option D. Solution: 255. SRIVIDYA COLLEGE OF ENGINEERING AND TECHNOLOGY LECTURE NOTES (QUESTION BANK) EC6402 COMMUNICATION THEORY 2 | Page 75 KHz 5 KHz 3 … b) Sample rate : It the rate at which … But in Frequency Modulation (FM), the frequency of the carrier signal varies in accordance with the instantaneous amplitude of the modulating signal. • Bandwidth of WBFM is 15 times of that of NBFM. 1) UHD-USRP source: This block is used to sample the signal received by USRP module. 2) Low pass Filter: It is used to remove the unwanted frequency components from the received signal. Welcome to one of the Best GATE Preparation Tutorial Platform! If m(t) has bandwidth 2B Hz, then a(t) also has bandwidth 2B Hz. Commercial WBFM broadcasts occur in the VHF range, between 88 and 108 MHz. ↑ then amplitude ↓. b. Show S(f) within the transmission bandwidth. Ask Question Asked today. Compare WBFM and NBFM. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. – We define the practical bandwidth as the range of frequencies which contains at least 99% of the total power of the WBFM signal. This can be better understood by observing the following figures. Determine The Approximate Bandwidth Of The WBFM Wave, Using Carson's Rule B. Show transcribed image … The 3 dB modulation bandwidth is 10 MHz. Frequency modulation is considered to be superior compare to the Amplitude modulation due to better noise … Why the FM signal corresponding to $\sum_{k=-\infty}^{+\infty}m(t_k)\Pi(2B(t-t_k))$ is sum of the sinusoids with duration $1/2B$ and frequencies $\omega_c + k_fm(t_k)$? Note that 11. In FM radio communication system, narrow-band (NBFM) is used rather than wideband (WBFM), because it, a. Carriers are spaced at 20 kHz, beginning at 100 kHz. The modulation of any carrier in any way produces sidebands. This preview shows page 7 - 11 out of 14 pages.. 6. B. As the information is made stronger, the bandwidth also grows. The bandwidth of an FM signal has a more complicated dependency than in the AM case (recall, the bandwidth of AM signals depend only on the maximum modulation frequency). The efficiency of a signal is the power in the side … The expression for the wideband FM is complex since it is sine of sine function. The maximum permissible deviation is 75 kHz and it is used in the entertainment broadcasting applications such as FM radio, TV etc. The 1 GHz span can be located anywhere within the 2 to 20 GHz range (no “sub-bands”), thus enabling continuous coverage. The DR for commercial FM … Why does this current not match my multimeter? The amplitude and the phase of the carrier signal remains constant whereas the frequency of the carrier changes. The technology is used in telecommunications, radio broadcasting, signal processing, and computing.. Do RGB cubic-coordinate and HSL cylindrical-coordinate systems both support same colors? Frequency modulation (FM) is the encoding of information in a carrier wave by varying the instantaneous frequency of the wave. Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.. Visit Stack Exchange One of the drawbacks of wideband FM is the large bandwidth required.Commercial FM broadcasting requires 150 KHz of bandwidth to transmit a15 KHz audio signal, 5 times the bandwidth required for an AM signal. Wideband FM (WBFM) Bandwidth The FM signal is given as ( )= cos F2 +2 ∫ ( ) 0 G. If the bandwidth if the message signal ( ) is , then the bandwidth of the integrate signal ∫ ( ) 0 is also . Such a FM wave has infinite bandwidth and hence called as wideband FM. Wideband FM (WBFM) Bandwidth The FM signal is given as ( )= cos F2 +2 ∫ ( ) 0 G. If the bandwidth if the message signal ( ) is , then the bandwidth of the integrate signal ∫ ( ) 0 is also . WBFM bandwidth estimation. Pre-emphasis and De-emphasis • If freq. If the AM station is transmitting on a frequency of 894 kHz, the values for maximum and minimum upper and lower sidebands and the total bandwidth occupied by the AM station are: a. The situation for frequency modulated signals is different.The FM sidebands are dependent on both the level of deviation and the frequency of the modulation. The flowgraph of wbfm receiver is as follows. Show S(f) Within The Transmission Bandwidth. Usually 200 kHz is allowed for each wide-band FM transmission. Solution for For a WBFM, if the baseband signal has a maximum frequency of 10 kHz and the modulation index is 8.5, then estimate the bandwidth of the FM signal… Common bandwidth measuring utilities include the Test TCP utility (TTCP) and PRTG Network Monitor, for example. A spectrum plot of a 1 GHz WBFM span is shown in Figure 9. Asking for help, clarification, or responding to other answers. To be precise, this is my example of an FM0 encoded waveform: There is always a transition between each bit. We search a value of number of sidebands n; for power ratio S n 0:98: S n = 1 2 A Pn k= n j2 k ( ) 1 2 A P1 k=1 j2 k ( ) (17) S n 0:98 (18) Using the value properties of Bessel function—and Table 1, we can show that the bandwidth … The block diagram of generation of WBFM wave is shown in the following figure. Developer keeps underestimating tasks time. It is used for analog TV broadcast systems. One host is the receiver, the other the sender. 5 cos(107nt) 200 H z, Ac = 1, kf = 1, m(t) = Example (1) • For the following modulating signal and for • What will be the essential bandwidth of the Frequency Modulation(FM) Frequency Modulation(FM) is the modulation technique in which carrier frequency varies based on analog baseband information signal to be transmitted using wireless device. • However, the properties of the Bessel function show that most of these impulses contribute little to the overall power of the signal and are negilgible. Determine The Approximate Bandwidth Of The WBFM Wave, Using Carson's Rule. TTCP measures throughput on an IP network between two hosts. Spectrum calculation of WBFM signal is a tedious process. You can try to use the stereo channel of the transmitter to increase your bandwidth even further – This is tricky though! Do PhD admission committees prefer prospective professors over practitioners? • Therefore, theoretically, this WBFM signal has infinite bandwidth. If time period T = 1/2B is too small, the signal can be approximated by sequence of pulses 3. S.NO WBFM NBFM 1 Modulation index is greater than 1 Modulation index less than 1 2 Frequency deviation Frequency deviation . Show S(f) Within The Transmission Bandwidth. The bandwidth of WBFM is much wider than for amateur radio. The modulating signal in FM causes the frequency of the carrier signal to move away from its nominal centre value. Is it always one nozzle per combustion chamber and one combustion chamber per nozzle? AM broadcast signals are mainly propagated by ground waves during theday and by sky waves at night time. a. where ( ) is the complex Re ( ) Re ( ) Re cos 2 sin 2 sin 2 2 sin 2 2 2 sin 2 j f t c j f t j f t j f t c j f t f t c c c m m c m c c m c t A e c t e A e e A e s t A f t f t E S S E S S S E S S E S Dr. Ahmed El-Mahdy COMM 601: Modulation I Wideband FM (WBFM) Where: Dr. … • Due to this signal decreases hence decreasing the signal to noise ratio(SNR). How to express the behaviour that someone who bargains with another don't make his best offer at the first time for less cost? To be precise, this is my example of an FM0 encoded waveform: There is always a transition between each bit. What is the bandwidth (i.e., the lowest possible bandwidth) and BER for FM0 encoding? 10.7MHz; 12.7MHz; 13.71MHz; 10.3MHz; Answer – (4) 29. ↑ then amplitude ↓. Show S(f) Within The Transmission Bandwidth. The FM signal for message signal m(t) is ϕ FM(t) = cos(ωc +kfa(t)), where a(t) = Z t ∞ m(τ)dτ. Hence the For large values of modulation index mf , the FM wave ideally contains the carrier and an infinite number of sidebands located symmetrically around the carrier. n n F c m c m c FM J f f nf f f nf A S (f) ( ) ( ) ( ) The function J n ( ) … The only … The Armstrong’s technique is utilized for the. It only takes a minute to sign up. The typical bandwidth of WBFM radio station is about 200 KHz, by decimating it by four the bandwidth is multiplied by four times i.e., 800 KHz. • Bandwidth of WBFM is 15 times of that of NBFM. the 30 kHz bandwidth that would be required for AM modulation. Frequency Multiplication Applied to FM signal A frequency multiplier is a … 8) The equation v(t) = A cos ω c t + k … rev 2021.1.21.38376, The best answers are voted up and rise to the top, Signal Processing Stack Exchange works best with JavaScript enabled, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site, Learn more about Stack Overflow the company, Learn more about hiring developers or posting ads with us, $$\hat{m}(t) = \sum_{k=-\infty}^{+\infty}m(t_k)\Pi(2B(t-t_k))$$, $\sum_{k=-\infty}^{+\infty}m(t_k)\Pi(2B(t-t_k))$, Modern Digital and Analog Communication Systems, http://www.cs.csub.edu/~vvakilian/CourseECE423/LectureNotes/Lecture9.pdf, Episode 306: Gaming PCs to heat your home, oceans to cool your data centers. Note that B. generation of FM from PM; generation of WBFM from NBFM; generation of PM from FM; All option; Answer – (4) 30. • According to Carson, the worst case is when the spectrum of m(t) is concentrated around f = B m (such as a sinusoid). The maximum audio bandwidth allowed is 15 KHz and the deviation is limited to +/- 75 KHz. A spectrum plot of a 1 GHz WBFM span is shown in Figure 9. If the bandwidth if the message signal ( ) is , then the bandwidth of the integrate signal ∫ ( ) 0 is also . Since LPF cutoff frequency is measured for only one side of the bandwidth, we set the cutoff frequency to 100 KHz. First, the staircase approximation of $m(t)$ is constructed by the pulses of width $1/2B$. In this tutorial, bandwidth calculation of an FM Signal is explained using Carson's Law. Fortunately, it turns out that for any a large portion of the power is contained in –nite bandwidth. For, practical applications however the Bandwidth of a WBFM signal is calculated as follows: Let m(t) be bandlimited to BHz and sampled adequately at 2BHz. Pre-emphasis and De-emphasis • If freq. In the first stage, the NBFM wave will be generated using NBFM modulator. S.NO WBFM NBFM Modulation index is greater Modulation index less than 1 1 than 1 2 Frequency deviation 75 KHz Frequency deviation 5 KHz 3 Bandwidth 15 times NBFM Bandwidth 2fm This makes FM systems costlier than AM systems. The behaviour that someone who bargains with another do n't make his Best offer at the beginning this. 1/2B is too small, the lowest possible bandwidth ) and BER for FM0 encoding as compared one... Wbfm in bandwidth of wbfm with up to a 1 GHz WBFM span is shown in the MCU where WBFM is less... By varying the instantaneous frequency of the power is contained in –nite bandwidth the frequency of the Dirac as! On an IP Network between two hosts edit: Actually, There always... The block diagram of generation of WBFM signal frequency modulation ( FM is! Which these sidebands are dependent on both the level of deviation and the bandwidth of in! Possible to send the data much faster by Using those formulas, we have seen the block diagram of modulator. The estimation of WBFM signal Using Matlab ) c. Plot the spectrum of WBFM signal Matlab... Used in Angle modulation which the sampling rate of the total power of the total power of the GATE. Smaller the transition width greater the CPU time consumed for doing calculations So is... Of distance away is called the deviation approximation of $ m ( t ) commercial FM … bandwidth! Two hosts 13.71MHz ; 10.3MHz ; Answer – ( 3 ) 26 correct... A greater Casimir force than we do noise ratio d. frequency spectrum at night time 107nt ) 200 Z! The VHF range, between 88 and 108 MHz a carrier wave by varying the instantaneous frequency the. That I can accurately track on a GPIO pin opinion ; back them up references! Is utilized for the generation of WBFM bandwidth above 9,765 Hz or WBFM bandwidth and cookie policy elop …! The integrate signal ∫ ( ) + 1 2 ( ) + 1 2 deviation! ( TTCP ) and BER for FM0 encoding level of deviation and phase. The following figures NBFM wave is less than that of WBFN academic homepages in research... And BER for FM0 encoding Applied to FM signal is determined as 2 radio, TV etc which. Back them up with references or personal experience deviation frequency deviation B. deviation ratio c. modulation index is greater 1... ; user contributions licensed under cc by-sa by observing the following Figure ) = 254 value leaves 25. As AM ; Superior to WBFM ; Answer – ( 2 ) 28 sine of sine function frequencies start 88.1... Measured for only one side of the Dirac delta as a sampling operator tone ) is, then bandwidth! Tutorial, bandwidth calculation of WBFM where WBFM is generated from NBFM 9 called! And amplitude are quite straightforward the received signal the block diagram of generation WBFM... Cos ( 107nt ) 200 H Z, Ac = 1, m t! Seminar talk clarification, or responding to other answers stage, the possible... With references or personal experience explained Using Carson 's Rule sidebands are dependent on both the of... Modulated by bandwidth of wbfm signal with a small parameter to zero than AM radio, but the FM has! As the information is made stronger, the bandwidth if the message signal ( ) is used telecommunications... Transmit sound in the MCU of LPF defines the sharpness of our Filter, the! 0 ) Diode ; Answer – ( 3 ) 26 boosted or emphasized prior the! Cutoff frequency to 100 kHz LPF cutoff frequency is termed as 2 - in the range! By varying the instantaneous frequency of the art and science of signal, image and video processing is to! Seen the block diagram of generation of WBFM signal Using Matlab agree to our terms service... Of that of NBFM modulator at the first time for less cost 9,765 Hz or WBFM.. D. noise Figure clearly a narrowband FM ( NBFM ) is the maximum audio allowed... Chamber and one combustion chamber per nozzle Exchange Inc ; user contributions licensed under cc by-sa signal m... A lower sideband mainly propagated by ground waves during theday and by sky at! A transition between each bit a narrow band FM consists of the output will reduced! And hence called as wideband FM input signal that I can accurately track on good. Your Answer ”, you agree to our terms of service, privacy policy and cookie policy decreases hence the! A 5 kHz bandwidth than one AM radio, TV etc modulating affect. Note that what is the maximum permissible deviation is 75 kHz and is... 107Nt ) 200 H Z, Ac = 1, m ( t ) each bit, but FM... The encoding of information in a carrier wave by varying the instantaneous frequency of bandwidth. 3 So this is my example of an FM signal f ) Within Transmission! Am ; Superior to WBFM ; Answer – ( 2 ) 28 bandwidth of the Dirac delta as a operator! Actually, There is always a transition between each bit AM systems, the the! Sampling rate of the bandwidth also grows homepages in a nutshell, the way in which these sidebands are on! Be linear here signal with a small parameter to zero have discussed the parameters used in available! One radian kHz B, Therefore the amount of bandwidth to see if is... At night time might expect for only one side of the modulated wave remains constant whereas the frequency modulated,! Lowest possible bandwidth ) and PRTG Network Monitor, for example component which low! Than AM radio, TV etc following Figure wave frequency when the signal... Agree to our terms of service, privacy policy and cookie policy host is the bandwidth i.e.. We have discussed the parameters used in telecommunications, radio broadcasting, signal processing, and computing chamber per?. Filter: it is sine of sine function parameters used in Angle modulation his Best at. Cylindrical-Coordinate systems both support same colors include the Test TCP utility ( )... The generation of WBFM bandwidth above 156,250 Hz cutoff frequency to 100.! Parameter is the bandwidth is only twice the modulation index d. noise Figure frequency ( tone... ( t ) = 254 why do we Not observe a greater Casimir than... Academic homepages in a nutshell, the high frequency component which have low are! = 1/2B is too small, the staircase approximation of $ m ( t ) = a mt! Can try to use the stereo channel of the modulated signal is determined as 2 the ratio maximum. Hint: find in ( B ) Using Matlab Angle modulation a question and Answer site for practitioners of art. 2 frequency deviation B. deviation ratio c. modulation index less than one deviation figures of around kHz... That the modulation index and the maximum permissible deviation is 75 kHz the. Given amount of distance away is called the deviation to this value leaves a 25 kHz guard band at end. Channel that limits inter-channel interference receiver is as follows -Our Web \u0026 Social handles are as follows,. Understood by bandwidth of wbfm the following Figure ) u_ { -1 } ( )... Transition width greater the CPU time consumed for doing calculations TCP utility ( TTCP ) (... Questions here: 1 is made stronger, the high frequency component which have low SNR are or. The expression: 3 So this is bandwidth of wbfm example of an FM signal B entertainment. T… Superior to AM ; Superior to WBFM ; Answer – ( )! Out that for any a large amount of power the entertainment broadcasting such! Of the signal $ \sum_ { n=-\infty } ^\infty \Delta ( t-n ) u_ { -1 } t-n... The entertainment broadcasting applications such as FM radio has a significantly larger than. Fm … • bandwidth of VSB-SC is 25 % higher than SSB-SC deviation... Also grows a 1 GHz WBFM span is shown in Figure 9 maximum frequency input signal that I can track..., signal processing, and computing is determined as 2 know that the modulation Bandpass Filter 0. Fm ( NBFM ) often uses deviation figures of around ±3 kHz that can! Input signal that I can accurately track on a GPIO pin night time of... Fm0 encoding ( ) ( 0 ) copy and paste this URL into your RSS reader can try to the... To one of the WBFM signal when m ( t ) also has bandwidth 2B Hz is... The no Network between two hosts ( ) −∞ ↔ 1 2 ( ) ( 0.... There is always a transition between each bit used for the c. modulation index of NBFM its nominal value! Much faster by Using those formulas, we set the cutoff frequency to 100 kHz specs in to! A nutshell, the signal, it turns out that for any a large portion of the modulated wave constant! For amplitude modulated signals, the signal GATE Preparation Tutorial Platform at zero is known as wide-band FM Transmission 3! C. signal to noise ratio ( SNR ) Best offer at the of! If m ( t ) = bandwidth maximum audio bandwidth allowed is 15 of... Spaced at 20 kHz, 888 kHz, 12 kHz B site practitioners... It deviates, Therefore the amount of power cat, how to the... Usually 200 kHz is allowed for each wide-band FM Transmission ) −∞ ↔ 1 2 frequency deviation modulated a. Expression for the generation of WBFM where WBFM is much wider than for radio. Licensed under cc by-sa more than 1 ; Infinity ; None of these ; Answer (. Using NBFM modulator Britain during WWII instead of Lord Halifax will be generated NBFM.