Description : To connect coaxial line to a parallel-wire _________ is the best to use. A. directional coupler B. quarter-wave transformer C. balun D. slotted line
Last Answer : C. balun
Description : To couple a coaxialline toa parallel-wire line,itisbesttouse a a. slotted line b.balun c. directional coupler d. quarter-wave transformer
Last Answer : b.balun
Description : Best choice of transmission line component to couple a coaxial line to a parallel-wire line A. Shorting B. Balun C. Slotted line D. Directional coupler
Last Answer : B. Balun
Description : What type of balun (balanced-to-unbalanced) is used in high frequency applications? A. Transformer type balun B. A specially configured coaxial transmission line C. A specially configured parallel-wire line D. A λ/2 transformer balun
Last Answer : B. A specially configured coaxial transmission line
Description : Fortransmission-line loadmatchingover a range offrequencies,itisbesttouse a a. balun b. broadband directional coupler c. double stub d. single stub of adjustable position
Last Answer : c. double stub
Description : Most mobile satellite array uses ___________ in transforming 50 to 150 Ω impedance. A. stub B. balun C. quarter-wavelength transformer D. microstrip tapers.
Last Answer : C. quarter-wavelength transformer
Description : A component that samples the microwave signal travelling in one direction down to the transmission line A. Isolator B. Combiner C. Directional coupler D. Attenuator
Last Answer : C. Directional coupler
Description : What would be the physical length of a tpical coaxial transmission line that is electrically one-quarter wavelength long at 14.1 MHz? A. 20 meters B. 3.51 meters C. 2.33 meters D. 0.25 meter
Last Answer : B. 3.51 meters
Description : It is useful to refer to an isotropic radiator. A. when comparing the gains of directional antennas B. when testing a transmission line for standing wave ratio C. when (in the northern hemisphere) directing the transmission D. when using a dummy load to tune a transmitter
Last Answer : A. when comparing the gains of directional antennas
Description : When is it useful to refer to an isotropic radiator? A. When comparing the gains of directional antennas B. When testing a transmission line for standing wave ratio C. When (in the northern ... ) directing the transmission in a southerly direction D. When using a dummy load to tune a transmitter
Last Answer : A. When comparing the gains of directional antennas
Description : What is the meaning of the term velocity factor of a transmission line? A. The ratio of the characteristic impedance of the line to the terminating impedance B. The index of shielding for coaxial ... The velocity of the wave on the transmission line divided by the velocity of light in a vacuum.
Last Answer : D. The velocity of the wave on the transmission line divided by the velocity of light in a vacuum.
Description : What is the meaning of the term velocity factor of a transmission line? A. The index of shielding for coaxial cable B. The velocity of the wave on the transmission line multiplied by the velocity of ... The velocity of the wave on the transmission line divided by the velocity of light in a vacuum
Last Answer : D. The velocity of the wave on the transmission line divided by the velocity of light in a vacuum
Description : A device that connects two dissimilar networks and performs the protocol conversion. A. Gateway B. Coupler C. Transformer D. Converter
Last Answer : A. Gateway
Description : To couple a coaxial line to a parallel wire line, it is best to use a: (1) A slotted line (2) Balun (3) Directional coupler (4) Quarter wave line transformer
Last Answer : To couple a coaxial line to a parallel wire line, it is best to use a: Balun.
Description : What medium is used by IBM token ring network that operates at either 4 Mbps or 16 Mbps? A. Twisted pair B. Coaxial cable C. Fiber-optic D. Parallel-wire line
Last Answer : A. Twisted pair
Description : Why is the physical length of a coaxial cable transmission line shorter than its electrical length? A. Skin effect is less pronounced in the coaxial cable B. RF energy moves slower along the ... higher in the parallel feed line D. The characteristic impedance is higher in the parallel feed line
Last Answer : B. RF energy moves slower along the coaxial cable
Description : _____ is an antenna with a number of half-wave antenna on it. A. Antenna array B. Tower C. Omni-directional D. Rhombic
Last Answer : A. Antenna array
Description : Radio wave concentration in the direction of the signal emitted by a directional antenna. A. Back lobe radiation B. Side lobe radiation C. Major lobe radiation D. Transmitted signal
Last Answer : C. Major lobe radiation
Description : ______ is an antenna array which is highly directional at right angles to the plane of the array? A. Broadside array B. End-fire array C. Turnstile array D. Log-periodic array
Last Answer : A. Broadside array
Description : What is the reactance property at the input of a shorted quarter wavelength line? A. A parallel LC circuit B. A pure inductive reactance C. A series LC circuit D. A pure capacitive reactance
Last Answer : A. A parallel LC circuit
Description : Which of the following is and impedance matching ration of coax balun? A. 2:8 B. 1:2 C. 4:1 D. 2:1
Last Answer : C. 4:1
Description : An RG-11/U foam coaxial cable has a maximum voltage standing wave of 52 V and a minimum voltage of 17 V. Find the value of the resistive load. A. 24.59Ω B. Either A or C C. 228.75Ω D. Neither A nor C
Last Answer : B. Either A or C
Description : Curl cannot be employed in which one of the following? a) Directional coupler b) Magic Tee c) Isolator and Terminator d) Waveguides
Last Answer : d) Waveguides
Description : What happens to reflected energy that enters a directional coupler that is designed to sample incident energy?
Last Answer : . The reflected energy adds at the absorbent material and is absorbed.
Description : in a directional coupler that is designed to sample the incident energy, what happens to the two portions of the wavefront when they arrive at the pickup probe?
Last Answer : The wavefront portions add.
Description : What is the purpose of the absorbent material in a directional coupler?
Last Answer : Absorb the energy not directed at the pick-up probe and a portion of the overall energy
Description : How far apart are the two holes in a simple directional coupler?
Last Answer : 1/4 wavelength.
Description : What is the primary purpose of a directional coupler?
Last Answer : Sampling energy within a waveguide.
Description : Describe a directional coupler.
Last Answer : A fiber optic coupler that prevents the transfer of power between input fibers.
Description : Describe the working of directional coupler with neat diagram.
Last Answer : Directional couplers are devices that will pass signal across one path while passing a much smaller signal along another path. One of the most common uses of the directional coupler is to ... . The frequency determines the separation of the two holes as a fraction of the wavelength.
Description : In a directional coupler: (1) Isolation (dB) equals coupling plus directivity (2) Coupling (dB) equals isolation plus directivity (3) Directivity (dB) equals isolation plus coupling (4) Isolation (dB) equals (coupling) (directivity)
Last Answer : In a directional coupler: Isolation (dB) equals coupling plus directivity.
Description : A load of 200 ohm is used to match 300 ohm transmission line to achieve SWR=1. Find out the required characteristic impedance of a quarter of a quarter wave transformer connected directly to the load.
Last Answer : Solution :
Description : Which coaxial connector is a more complex and expensive but do a better job in maintaining the electrical characteristics of the cable through the interconnections? A. N-type connector B. F-type connector C.BNC D. PL-259
Last Answer : A. N-type connector
Description : What do you call a cable consisting of twisted pairs of conductors, each separately insulated? A. Microstrip line B. Strip line C. Quad D. Coaxial cable
Last Answer : C. Quad
Description : Which of the following is not a bounded medium? A. Coaxial line B. Two-wire line C. Waveguide D. Free space
Last Answer : D. Free space
Description : Which of the following is considered the most frequently used transmission line? A. Two-wire open line B. Twin lead C. Rigid coaxial line D. Flexible coaxial line
Last Answer : D. Flexible coaxial line
Description : A coaxial cable has 7dB of reflected power when the input is 5 watts. What is the output of the transmission line? A. 5 watts B. 2.5 watts C. 1.25 watts D. 1 watt
Last Answer : D. 1 watt
Description : What line has a typical velocity factor of about 0.8? A. Shielded pair B. Flexible coaxial C. Twin-lead D. Open-wire line
Last Answer : C. Twin-lead
Description : What is the characteristic impedance of a coaxial line with the following data: inner diameter = 0.2 in., center conductor diameter = 0.06 in., insulation = Teflon. A. 200Ω B. 75Ω C. 50Ω D. 150Ω
Last Answer : C. 50Ω
Description : A transmission line consisting of two conductors that have equal resistance per unit length. A. Unbalanced line B. Open-wire line C. Balanced line D. Coaxial line
Last Answer : C. Balanced line
Description : The outer conductor of a coaxial transmission line is always grounded at the A. Input only B. Input and output C. Output only D. Point of high SWR
Last Answer : B. Input and output
Description : Not a reason for the use of an antenna coupler. A. To make the antenna look resistive B. To provide the output amplifier with the correct load impedance C. To discriminate against harmonics D. To prevent re-radiation of the local oscillator
Last Answer : D. To prevent re-radiation of the local oscillator
Description : Which one is an antenna coupling unit? A. Coupler B. Diplexer C. Lecher wire D. Duplexer
Last Answer : B. Diplexer
Description : Referred to as a ferrite device that can be used in lieu of a duplexer to isolate a microwave transmitter and receiver when both are connected to the same antenna. A. Isolator B. Circulator C. Coupler D. Diode.
Last Answer : B. Circulator
Description : What is an opto-coupler IC?
Last Answer : Opto-coupler IC is a combined package of a photo-emitting device and a photosensing device.Examples for opto-coupler circuit : LED and a photo diode, LED and photo transistor, LED and Darlington. Examples for opto-coupler IC : MCT 2F , MCT 2E .
Description : What is the input impedance of a transmission line if its characteristic impedance is 300 Ω and the load is 600 Ω? Assume a quarter wavelength section only. A. 150 kΩ B. 150 mΩ C. 150 Ω D. 2 Ω
Last Answer : C. 150 Ω
Description : How quarter wave transformer is used for impedance matching.
Last Answer : In all applications of transmission line, it is required that the load be matched to line, Which requires tuning out the unwanted load reactance and the transformation of resulting impedance to the required value ... Step down transformer If ZL <Zo then it acts as a Step up transformer
Description : List and explain the properties of quarter wave transformer.
Last Answer : Properties of quarter wave transformer: 1. Impedance transfomation: it provides impedance transformation upto the highest frequencies and is compatible with transmission line. 2. Impedance inversion: if ZL is ... or step up transformer,depending on whether ZL IS greater than or less than ZO.
Description : How does spatial isolation technique in satellite communications avoid interference? A. Use of different polarity antennas B. Use of different types of antennas C. Employment of highly directional spot-beam antennas D. Use of low gain antennas
Last Answer : C. Employment of highly directional spot-beam antennas
Description : A disadvantage of using a trap antenna. A. It will radiate harmonics B. It can only be used for single-bad operation C. It is too sharply directional at lower frequencies D. It must be neutralized
Last Answer : A. It will radiate harmonics