This page covers advantages and disadvantages of Diode. The negative resistance in a BARITT diode is obtained on account of the drift of the injected holes to the collector end of the diode, made of p-type material. The figure below represents the negative resistance characteristic of IMPATT diode with respect to transit angle: Hence in this way current through an IMPATT diode is generated. Communications lasers are used with optical fiber, rather than in open links, to, d. ensure that people are not blinded by them, 41. Following are the disadvantages of IMPATT diode: It has high noise figure due to avalanche process & higher operating current. The biggest disadvantage of the IMPATT diode is its, a. lower efficiency than that of the other microwave diodes, 33. Schottky Diode. Home » Communications » Questions and Answers » Kennedy Questions and Answers ». BARITT Diode is consist of two back to back diode in its construction, so when potential is applied, most of the voltage drop occurs across the reverse biased diode region.BARITT Diode operation is based on the Punch through Effect which is when the voltage is increased till the edges of the depletion region meet, then a condition occurs that is known as Punch through effect. MCQ in Microwave Communications Part 11 as one of the Communications Engineering topic. Each one has its own advantages and disadvantages. Jan 07,2021 - Test: Communication System- 2 | 25 Questions MCQ Test has questions of Electrical Engineering (EE) preparation. The ruby maser has been preferred to the ammonia maser for microwave amplification, because the former has, 35. The biggest disadvantage of the IMPATT diode is its A. low efficiency than the other microwave diodes B. low power handling ability C. high noise D. inability to provide pulsed operation . For best low-level noise performance in the X-band, an amplifier should use, 11. It is, 22. Laser diodes. A tunnel diode is loosely coupled to its cavity in order to, b. increase the available negative resistance, d. allow operation at the highest frequencies, 28. Typically noise figure of IMPATT is about 30 dB. Breakdown occurs in the region very close to the P+ (i.e. 15 A Gunn diode is a negative resistance device, which is used as source of microwaves. It also has very high levels of harmonics as a result of the short current pulses that are used. (D) Inability to provide pulsed operation. The magnetic field is used with a ruby maser to, a. provide sharp focusing for the electron beam, 34. What is the number of p-n junctions ? The biggest disadvantage of the IMPATT diode is its A. lower efficiency than for the other microwave diodes B. low power-handling ability C. high noise D. inability to provide pulsed operation . 3. FETs are preferred to bipolar transistors at the highest frequencies because they, b. lend themselves more easily to integration, 10. 20. Indicate the falsestatement. Although the TRAPATT diode provides a much higher level of efficiency than the IMPATT, its major disadvantage is that the noise levels on the signal are even higher than they are when using an IMPATT. IMPATT diode. A parametric amplifier sometimes uses a circulator to, b. allow the antenna to be used simultaneously for transmission and reception, c. separate the signal and idler frequencies, 25. Crystal diode C. Schottky barrier diode D. Backward diode . 38. Disadvantages An advantage of stripline over microstrip is its, a. easier integration with semiconductor devices, c. higher isolation between adjacent circuits, 9. Also provides professionals with materials for their lectures and practice exams. (C) High noise. c. inability to provide pulsed operation. The biggest disadvantage of the IMPATT diode is its a lower efficiency than from ENGINEERIN ECEN 404 at Polytechnic University of the Philippines IMPATT diodes are most powerful continuous wave solid state microwave power sources. The biggest disadvantage of the IMPATT diode is its: Lower efficiency than that of the other microwave diodes. One of the following is not used as a microwave mixer or detector: 15. inoyBIX educates thousands of reviewers and students a day in preparation for their board examinations. For its operation as a microwave signal generator, IMPATT diode is operated under reverse bias conditions. 12. B TM11. Copyright 2018 InterviewMania.com - All rights reserved. The main advantage is their high-power capability; single IMPATT diodes … For Gunn diodes, gallium arsenide is preferred to silicon because the former, a. has a suitable empty energy band, which silicon does not have, c. has a lower noise at the highest frequencies, d. is capable of handling higher power densities, 32. For a given average power, the peak output power of a ruby laser may be increased by, d. dispensing with the Fabry-Perot resonator, 40. With the ability to operate at frequencies between about 3 and 100 GHz or more, one of the main advantages of this microwave diode is the relatively high power capability of the IMPATT diode. In IMPATT diodes, the carrier injection is quite noisy due to the impact ionization. 2010-02-24 05:52:48. Indicate which of the following diodes will produce the highest pulsed power output: 13. It is a diode made up of an intrinsic semiconductor sandwiched between narrow p-type material and a narrow n-type material. Then idler frequency is, 23. IMPATT diode I-V characteristic . 13. The biggest advantage of gallium antimonide over germanium for tunnel diode use it that former has a, 30. D 1. At the moment, Pinoybix has become one of the most trusted engineering review sites helping thousands of aspiring engineers achieve their goals. On a historical note, IMPATT diode is also called ‘Read’ diode in honor of W.Т. The IMPATT diode or IMPact ionisation Avalanche Transit Time diode is an RF semiconductor device that is used for generating microwave radio frequency signals. If high-order frequency multiplication is required from a diode multiplier, a. the resistive cutoff frequency must be high, b. a small value of the base resistance is required, d. a large range of capacitance variation is needed, 21. Wiki User Answered . Advantages. 11) The type of antenna to be used for producing circularly polarized beams is a) pyramidal horn b) log-periodic array c) paraboloid d) helical antenna 12) In LOS-line of sight propagation systems, to take account of normal refraction, an effective earth radius factor k is used whose value is a) 4/3 b) 4 c) ¾ ... Read more Microwave Engineering MCQ Questions Answers Electronics ECE D TE11. The main disadvantage of this diode is that the level of noise on the signal is even higher than IMPATT. It provides high operating range.
This state of diode is known as forward biased state. 0 0 1 0 0 0 0. I can assure you that this will be a great help in reviewing the book in preparation for your Board Exam. Previous Question (B) Low power handling capabilities. Low power-handling ability. 13. b. increase the population inversion. Discuss in Forum . Asked by Wiki User. The biggest advantage of the TRAPATT diode over the IMPATT diode is its a) Low noise b) Higher efficiency c) Ability to operate at higher frequencies d) Lesser sensitivity to harmonics Ans: Option b) 14. A 0. The central region where large number of positive and negative ions on n-region and p-region respectively accumulates is called Depletion Layer. A. PIN diode B. This is the Multiple Choice Questions in Chapter 12: Semiconductor Microwave Devices and Circuits from the book Electronic Communication Systems by George Kennedy. A major drawback of using IMPATT diodes is the high level of phase noise they generate. For a microwave transistor to operate at the highest frequencies, the (indicate the false answer), 19. Q. A parametric amplifier has an input and output frequency of 2.25 GHz, and is pumped at 4.5 GHz. The Biggest Disadvantage the IMPATT Diode has is its - Basic electrical Engineering « Previous Question. Read, who first proposed the p+-n-i-n+ structure based on the forward-biased PN junction method of carrier injection in 1958. Standard PN junctions and IMPATT diodes have similar I-V characteristic curve shown in Fig. C 2. C TM01. (13) The biggest disadvantage the IMP ATT diode has is its (a) Low Efficiency (b) high noise (c) Low BW (d) inability to provide pulse operation (e) low power handling ability 9 10 11. A maser RF amplifier is not really suitable for, 37. BARITT Diode. They operate at frequencies of about 3 and 100 GHz, or higher. At the same time, when a greater number of impurities is added, narrow depletion region occurs. These are set so that avalanche breakdown occurs. The biggest advantage of the TRAPATT diode over the IMPATT diode is its, c. ability to operator at higher frequencies. These diodes are used in a variety of applications from low power radar systems to alarms. The negative resistance in a tunnel diode, a. is maximum at the peak point of the characteristic, b. is available between the peak and valley points, d. may be improved by the use of reverse bias, 29. An IMPATT diode (IMPact ionization Avalanche Transit-Time diode) is a form of high-power semiconductor diode used in high-frequency microwave electronics devices. View Answer. It provides reliable operation at high temperature. A wide and big depletion region is formed when a smaller number of impurities is added to p-n junction diode. To create an output, a DC supply applied to the IMPATT which oscillates when a suitable tuned circuit is in circuit. The biggest disadvantage of the IMPATT diode is its: Lower efficiency than that of the other microwave diodes. The Biggest Disadvantage the IMPATT Diode has is its (A) Low Efficiency (B) High Noise (C) Low BW (D) Inutility to provide Pulse Operation. It has very small interelectrode capacitances. In BARITT diodes, to avoid the noise, carrier injection is provided by punch through of the depletion region. The output from a laser is monochromatic; this means that it is, 39. Read more about the IMPATT structure & fabrication; IMPATT diode operation. Impatt diode 1. A varactor diode may be useful at microwave frequencies (indicate the false answer). Microwave engineering miscellaneous. Large-signal analysis of an IMPATT diode is presented, where the effect of harmonic-frequency circuits is included. P Parametric amplifiers and masers are similar to each other in that both (indicate false statement), d. generally required circulators, since they are one-port devices, 36. The biggest advantage of the TRAPATT diode over the IMPATT diode is its a) Low noise b) Higher efficiency c) Ability to operate at higher frequencies d) Lesser sensitivity to harmonics Ans: Option b) 14. Negative resistance is obtained with a Gunn diode because of, a. electron transfer to a less mobile energy level, b. avalanche breakdown with the high voltage gradient, d. electron domains forming at the junction, 31. The ruby laser differs from the ruby maser in that the former, 38. It shows compactness in size. The shot noise is generated in the device due to high operating current. Indicate the false statement. Gallium antimonide over germanium for tunnel diode use it that former has, 35 its a high.... ( i.e a diode which also has very high levels of harmonics as a result of the other microwave.... Which is the dominant mode in rectangular waveguides is formed when a tuned. Because the former has a, 30 and every Questions to increase the chance of the. 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