Antennas.docx

AntennasQuestText Choice1 Choice2 Choice3 Choice4 Subj

_____ is an antenna with a number of half-wave antenna on it.

Antenna array Tower Omni-directional Rhombic Antennas

_____ is an open-ended slot antenna. Notch antenna Rhombic antenna Helical antenna Cassegrain antenna Antennas_____ is the angle between the half-power radiation points. Beamwidth Critical angle Angle of elevation Azimuth Antennas_____ is the horizontal pointing angle of an antenna. Azimuth Angle of elevation Beamwidth Right angle Antennas_____ is the measurement of a unilateral antenna properties of directivity.

Beamwidth Bandwidth Antenna gain Phase angle Antennas

_____ of an antenna is a measure of how the antenna concentrates its radiated power in a given direction.

Gain Efficiency Power Polarization Antennas

A common antenna employed in direction-finding apparatus is

Loop Rhombic In-line Folded unipole Antennas

A common omnidirectional microwave antenna is the Bicone Helical Horn Parabolic reflector AntennasA comparison of the output, in a particular direction of the antenna in question and a reference antenna:

Antenna gain Antenna efficiency Directivity Antenna power Antennas

A convenient method of determining antenna impedance. Smith chart Stub matching Trial and error Reactance circle AntennasA device that converts high frequency current into electromagnetic wave is known as

Antenna Reflectometer Frequency converter Microphone Antennas

A device that radiates electromagnetic energy and/or intercepts electromagnetic radiation.

Antenna Transceiver Transmission line Transmitter Antennas

A device whose function is to radiate electromagnetic energy and/or intercept electromagnetic radiation.

Antenna Transmitter Transmission line Transceiver Antennas

A directional antenna with two or more elements is known as

Array Ground plane Loop Folded dipole Antennas

A half wave antenna has a center impedance of 70 ohms. It is coupled to a flat 600 ohms transmission line through a quarter wavelength transmission line. Determine the required impedance of the quarterwave section.

205 ohms 210 ohms 250 ohms 245 ohms Antennas

A helical antenna is made up of a coil and a Reflector Director Dipole Horn Antennas


A highly directional antenna radiating a beam of electromagnetic radiation

Beam antenna Half-wave dipole Hertz antenna Marconi antenna Antennas

A horizontal antenna is Horizontally polarized Vertically polarized Centrally polarized Circularly polarized AntennasA horizontal radiation pattern of a dipole is Figure eight Circle Clover leaf Narrow beam AntennasA horizontal radiation pattern of vertical dipole is a Circle Figure eight Narrow beam Clover leaf AntennasA loudspeaker designed to reproduce middle-frequency sound is

Driver Woofer Tweeter Terminator Antennas

A non-reactive, non-radiating load of 50 Ohms connected to the antenna terminal used during transmitter testing.

Artificial antenna Unity gain antenna Standard antenna None of the above Antennas

A popular half-wave length antenna is the Dipole Ground plane End0fire Collinear AntennasA popular vertical antenna is the Ground plane Dipole Collinear Broadside AntennasAn ungrounded antenna near the ground Acts as an antenna array Is unlikely to need a

ground screenMust be horizontally polarized

Acts as a single antenna of twice the height

Antennas

An ungrounded antenna near the ground ____. Acts as an antenna array Acts as a single antenna of twice the height

Is unlikely to need an earth mat

Must be horizontally polarized

Antennas

Another name for Far Field radiation of a parabolic antenna is called ________ region.

Fraunhofer Fresnel Troposphere None of the above Antennas

Antenna polarization is determined by The direction of the electric field vector

The frequency of the radiated wave

The direction of the radiated wave

The direction of the magnetic field vector

Antennas

Antenna polarization is determined by: The direction of the electric field vector

The direction of the radiated wave

The direction of the magnetic field vector

The frequency of the radiated wave

Antennas

Antenna which is not properly terminated. Resonant antenna Non-resonant antenna Isotropic antenna Whip AntennasIf the antenna current increases 3.3 times how much does the radiated power increase?

10.89 times 3.3 times 6.6 times 9.9 times Antennas

If the current ratios of two or more elements must be held 5% and the phase angle to 3 degrees, the antenna is called a __________.

Critical phase array End fire array Broadband array Wideband array Antennas

If the radiated power increased by 10.89 times, the antenna 3.3 times 6.6 times 1.82 times 10.89 times Antennas


current increases byRefers to a type of beam antenna which uses two or more straight elements arranged in line with each other.

Yagi antenna Dipole antenna Whip antenna Rhombic antenna Antennas

A unity gain antenna. Isotropic Dummy Half-wave dipole Rhombic AntennasIn half wave dipole antenna, maximum radiation occurs Broadside to the

antennaOff the ends At a 45 degree angle

direction of the dipoleWhen end effects are reduced to zero

Antennas

An increase in the effective power radiated by an antenna in a certain desired direction at the expense of power radiated in other direction.

Antenna gain Antenna back lobe ratio Antenna total ratio Antenna efficiency Antennas

In testing transmitter to prevent interfering with other stations which type of antenna must be used?

Dummy antenna Hertzian antenna Void antenna Isotropic antenna Antennas

Most radar antennas use a Horn & parabolic reflector

Collinear array Dipole Broadcast array Antennas

The front-to-back ratio of an antenna which radiates 500W in a northerly direction and 50 W southerly direction.

10 dB 2500 dB 100 dB 20 dB Antennas

The gain of a Hertzian dipole with respect to an isotropic antenna is

1.76 dB 2.15 dB 4.15 dB 5.15 dB Antennas

The gain of four identically polarized antennas stacked one above the

6 dB over the gain of one antenna




Antennas

The half power points in the radiation beam of a directional antenna is equal to

0.707 times the maximum value

0.707 times its minimum value

1.414 of max value None of the above Antennas

The horizontal pointing angle of an antenna. Azimuth Bandwidth Beamwidth Angle of elevation AntennasThe standard reference antenna for the directive gain is the Isotropic antenna Infinitesimal dipole Elementary doublet Half-wave dipole AntennasA radar antenna using multiple dipole or slot antennas in a matrix with variable phase shifters is called a(n)

Phase array A Scan Broadside Circular polarized array Antennas

A receiving antenna will remain as efficient when used as transmitting antenna, provided that

The receive and transmit frequencies are the same

The decibel gain is maintained constant

Low loss transmission line are used

All of the above Antennas


A receiving antenna will remain as efficient when used as transmitting antenna, provided:

All of the above Low loss transmission lines are used

The received and transmit frequencies are the same

The decibel gain is maintained constant

Antennas

A simple half-wavelength antenna radiates the strongest signal.

At right angles to its axis Parallel to its axis At 45 degrees to its axis At 60 degrees to its axis Antennas

A term for a numerical ratio that relates the performance of one antenna to that of another real or theoretical antenna.

Antenna gain Conversion gain Effective radiated power Peak envelope power Antennas

A theoretical antenna in free space which transmits and recieves with the same signal strength in all directions:

Isotropic antenna Directional antenna Flat-plate antenna None of the above Antennas

A type of an ungrounded antenna is a/an ____ antenna. Hertz antenna Isotropic antenna Parabolic antenna Marconi antenna AntennasA type of array antenna which basically consists of one half-wave driven dipole. one reflector and one director.

Yagi-Uda Broadside Collinear Hertzian dipole Log periodic Dipole Array Antennas

A type of array antenna which consists of one half-wave driven dipole, one reflector and one director.

Yagi-Uda Hertzian dipole Broadside collinear Log-periodic dipole array Antennas

All elements in a beam ________ antennas are in a line. Collinear Yagi Broadside Log-periodic AntennasAn antenna has a 15 dB gain and is fed by a transmitter with 2 kW output transmission line losses are 0.6 dB. What is the ERP of the peak main beam of the antenna.

47.41 dBw 47.41 dBm 47.41 dB 47.41 dBK Antennas

An antenna has a power gain of 15. The power applied to the antenna is 32 W. The effective radiated power is

480 W 32 W 15 W 120 W Antennas

An antenna that is circularly polarized is the Helical Small circular loop Parabolic reflector Yagi-Uda AntennasAn antenna that transmits or receives equally well in all directions is said to be

Omnidirectional Bidirectional Unidirectional Quasidirectional Antennas

An antenna which has a power gain of 30 dB would mean it could increase that output of the transmitter by:

1,000 times 10,000 times 100 times 1 million times Antennas

An antenna which has an omnidirectional radiation pattern is the

Vertical whip antenna Dipole antenna Long-wire antenna Yagi antenna Antennas

An antenna which has an omnidirectional radiation pattern. Vertical whip antenna Long wire antenna Dipole antenna Yagi antenna AntennasAn antenna which is not resonant at a particular frequency Aperiodic Boresight Cassegrain Top-loaded Antennas


and so can be used over a wide band of frequencies is calledAn antenna which is one-tenth wavelength long. Elementary doublet Hertzian dipole Loop antenna Marconi antenna AntennasAn antenna which is used very frequently but almost entirely as a reception antenna and is usually found on the back of ac-dc radios.

Loop antenna Folded antenna Rhombic antenna Turnstile antenna Antennas

An antenna with unity gain. Isotropic Half-wave dipole Rhombic Whip AntennasAn antenna with very high gain and very narrow beamwidth. Parabolic dish antenna Helical antenna Discone antenna Horn antenna AntennasAn isotropic antenna has a gain of 1 10 100 0 AntennasBest description of a collinear and broadside antenna radiation pattern.

Bidirectional Unidirectional Omnidirectional Perfect circle Antennas

Calculate the angle for an antenna using a polar mount at latitude of 65°.

6.50° 5.25° 6.45° 7.50° Antennas

Calculate the gain of a 3 m paraboloid reflector used at 2 GHz.

2400 2500 2300 2200 Antennas

Conductors in a multielement antennas that do not receive energy directly from the transmission line are known as

Parasitic element Driven element The boom Receptors Antennas

Defined as the ratio of the power density in a particular direction of one antenna to the power density that would be radiated by an isotropic antenna

Directive gain Antenna gain Efficiency Power gain Antennas

Determine the dB gain of a receiving antenna which delivers a æV signal to a transmission line over that of an antenna that delivers a 20 æV signal uner identical circumstances.


Device that radiates electromagnetic energy and/or intercept electromagnetic radiation.

Antenna Transceiver Transmitter Transmission line Antennas

Earth station uses what type of antenna? Cassegrain antenna Torodial antenna Helical antenna Despun antenna AntennasERP is the theoretical power radiated by the antenna multiplied by ___ of the antenna.

Isotropic power gain K factor Loss Length Antennas

Every antenna will have the same properties (i.e. freq., gain, Reciprocity theorem Duplicity Shell's theorem Isotropic property Antennas


radiation pattern, bandwidth, etc. ). This is known as:Faraday rotation and spin modulation can be minimized using which type of antenna?

A circularly polarized antenna

A nonpolarized antenna An isotropic antenna A log-periodic antenna Antennas

Gain of a half-wave dipole antenna over isotropic. 2.15 dB 1.76 dB 1 dB 6 dB AntennasGain of an isotropic antenna. 0 dB - 1 dB 1 dB 2 dB AntennasGain of Hertzian dipole with respect to an isotropic antenna. 1.76 dB 5.15 dB 4.15 dB 2.15 dB AntennasGiven horizontally polarized antenna for maximum reception, the receiving antenna must be,

Horizontally polarized Vertically polarized 60 deg. with respect to earth's surface

45 deg. with respect to earth's surface

Antennas

Harmonic suppressor connected to an antenna. Low pass filter Tank circuit M-derived filter High pass filter AntennasHow much current flows into the antenna having a radiation resistance of 300 ohms radiating 5 kW?

4.08 A 3.08 A 2.08 A 5.08 A Antennas

How will you increase the gain of an antenna? By focusing the radiated energy in one desired direction

By adding several antennas in parallel

By making antenna rods thicker

By making antenna size larger

Antennas

If 4 kW antenna produces 50 uV/m in a receiving antenna, a 16KW will produce ____.

100 uV/m 200uV/m 10uV/m 20uV/m Antennas

If 4 kW in antenna produces 50 microvolt/m in a receiving antenna a 16 kW will produce _________.

100 uV/m 20 uV/m 10 uV/m 200 uV/m Antennas

If an isotropic antenna is defined as a perfect antenna radiating equally in all directions with a gain of 1.0, what is its gain in dB?

0 1 2 3 Antennas

In a half-wave dipole maximum radiation occurs Broadside of the antenna

Off the ends At 45 deg. angle to the direction of dipole

When the end effects are reduce to zero

Antennas

In a Yagi antenna, The director is shorter than the driven element.

The elements are spaced at least one wavelength apart

The reflectors are shorter than the driven element

There are usually more reflectors than the directors

Antennas

In a Yagi antenna, the amximum direction of radiation is toward the

Director Driven element Reflector Sky Antennas


In order to have an effective radio antenna, the design of its radiator must have a minimum length equivalent to _________.

Wavelength/4 Wavelength/10 Wavelength/6 Wavelength/3 Antennas

In practice, the transmission lines are almost connected to antennas that have a

Resistive load at a resonant frequency

Capacitive load Resitive load whose resistance is less than Zo

Resistive load whose resistance is greater than Zo

Antennas

In shipboard stellite dish antenna system, azimuth is refered as the ___.

Horizontal aiming of the antenna

Vertical aiming of the antenna

North to East 0 to 90 degrees Antennas

Indicate the antenna that is not wideband antenna. Marconi Discone Helical Folded dipole AntennasIndicate the antenna that is not wideband: Marconi Helical Folded dipole Discone AntennasIndicate which of the following reasons for using a counterpoise with antennas is false:

Protection of personnel working underneath

Impossibility of a good ground connection

Provision of an earth for the antenna

Rockiness of the ground itself

Antennas

Is a transmitter supplies 8 kW to the antenna when it is unmodulated, determine the total radiated power when modulated at 30%.

8.36 kW 5 kW 20 kW 15 kW Antennas

Is said to exist below the ground and is a true mirror image of the actual antenna.

Image antenna Dipole antenna Marconi antenna Hertz antenna Antennas

It is the horizontal point angle of an antenna Angle of Elevation Bandwidth Azimuth Right angle AntennasIt is the minimum distance from the transmit antenna measured along the surface of the earth that a skywave of a given frequency will be radiated to earth.

Skip distance Path length Radio horizon Optical horizon Antennas

Known as a grounded l/4 (lambda/4) antenna. Marconi antenna Hertz antenna Image antenna Dipole antenna AntennasOne of the following can be best attained by a trap antenna in radio communication?

Multifrequency band operation

Increase transmitter gain

Directionality Effective filter to noise signal

Antennas

One of the following consists of nonresonant antennas. The rhombic antenna The folded dipole The end-fire array The broadside array AntennasOne of the following consists of nonresonant antennas: Rhombic antenna Folded dipole End-fire array Broadside array AntennasOne of the following is not a reason for the use of an antenna coupler.

To prevent reradiation of the local oscillator

To discriminate against harmonics

To provide the output amplifier with the correct

To make the antenna look resistive

Antennas


load impedanceOne of the following is NOT an omnidirectional antenna: Log-periodic Half-wave dipole Discone Marconi AntennasOne of the following is very useful as a multiband HF receiving antenna. This is the

Square loop Conical horn Folded dipole Log-periodic Antennas

One of the following is very useful as a multiband HF receiving antenna. This is the:

Log-periodic Conical horn Square loop Folded dipole Antennas

One thousand watts of signal power is applied to an antenna. The antenna gain is equal to 40 dB. What is the EIRP ?

110 dBm 100 dB 100 dBm 110 dBW Antennas

Radio wave concentration in the direction of the signal emitted by a directional antenna.

Major lobe radiation Side lobe radiation Backlobe radiation Transmitted signal Antennas

Shortening effect of an antenna that makes it appear as if it were 5% longer.

End effect Flywheel effect Skin effect Capture effect Antennas

Space diversity transmission means transmitting and receiving on two or more

Antennas operating on the same frequency

Antennas operating on two different frequencies

Different frequencies Identical frequencies Antennas

The length of a doublet at 27 MHz is 18.2 ft 17.3 ft 8.67 ft 34.67 ft AntennasThe length of a ground plane antenna at 146 MHz is 1.68 ft 1.6 ft 2.05 ft 3.37 ft AntennasThe length of a half-wave dipole for a 28 MHz is approximately

17 ft 23 ft 30 ft 34 ft Antennas

The length of a Marconi antenna to operate with 985 kHz is _______.

250 ft. 200 ft. 500 ft. 999 ft. Antennas

The ability of the radar to determine the bearing of a target depend upon the

Antenna directivity Speed of light Speed of the target Frequency of the signal Antennas

The antenna radiates ______ polarized waves when the transmitter antenna is horizontally installed.

Horizontally Vertically Negatively Circularly Antennas

The antenna separations (in meters) required for optimum operation of a space diversity system can be calculated from:

S = 3wR/L S = 2wR/L S = wR/3L S = wR/L Antennas

The antenna that can only receive a television signal is TVRO Reference Antenna Isotropic Antenna Yagi Uda Antennas


The distance from the transmitting antenna to the point where direct waves strike the earth is called:

Radio horizon Optical horizon Geometric horizon The line of sight Antennas

The elementary doublet is a theoretical antenna which is used as a standard to which all the other antenna characteristics can be compared and is sometimes called as

Hertzian dipole Marconi antenna Yagi antenna Loop antenna Antennas

The frequency of operation of a dipole antenna cut to a length of 3.4 meters is

44 MHz 88 MHz 22 MHz 11 MHz Antennas

The frequency of operation of a dipole antenna cut to length of 3.4 m.

42.9 MHz 31.5 MHz 83.8 MHz 38.8 MHz Antennas

The impedance of a dipole antenna is about 73 ohms 50 ohms 300 ohms 36 ohms AntennasThe input RF power to a transmission line is 1000 W. The transmission line introduces a loss of 7 dB and is used to feed an antenna whose power gain is 3 dB. What is the ERP ofthis antenna?

400 W 500 W 600 W 700 W Antennas

The input terminal impedance at the center of a folded dipole antenna is


The loss that would be obtained between two isotropic antennas in free space.

Free space attenuation Obstacle loss Feeder loss Branching loss Antennas

The magnetic field of an antenna is perpendicular to the earth. The antenna polarization is

Horizontal Vertical Circular Can not be determined from the info given

Antennas

The Marconi antenna can stil be resonated inspite of being physically short by a quarter wavelength due to the effect of

Ground image antenna Being grounded Vertical construction Vertical polarization Antennas

The Marconi antenna can still be resonant inspite of being physically short by a quarter wavelength due to the effect of:

Ground image antenna Being grounded Vertical construction Vertical polarization Antennas

The maximum length of a Marconi antenna to operate at standard with 985 kHz signal is

237.258 ft. 249.746 ft. 212.284 ft. 237.563 ft. Antennas

The maximum number of turns a helix antenna must have. 3 4 5 6 AntennasThe minimum number of turns a helix antenna must have. 6 5 4 3 Antennas


The most widely used microwave antenna is a Horn Single-loop Quarter-wave probe Half-wave dipole AntennasThe non-metalic cover of a disc type antenna is called ____. Radome Shield Dome Dust Cover AntennasThe non-metallic cover of a disc-type antenna is called : Radome Shield Dome Dust cover AntennasThe non-metallic cover of a disc-type antenna is called a: Radome Shield Dome Dust Cover AntennasThe number of ground radials usually use by a wavelenght/4 vertical AM broadcast antenna is

24 12 32 8 Antennas

The output of a helical antenna is Circularly polarized Vertically polorized Horizontally polorized ! Vertical & horizontally polorized

Antennas

The point where the antenna is mounted with respect to the parabolic reflector is called the

Focal point Center Locus Tangent Antennas

The polarization of a discone antenna is ____. Vertical Horizontal Omnidirectional Directional AntennasThe product of the power supplied to the antenna to its gain relative to a half-wave dipole in a given direction.

ERP Carrier power Peak-envelope-power Radiated power Antennas

The purpose of the Adcock antenna is to Eliminate the effet of night error

Aid the loop antenna directivity

Develop a less exact nul indication

Increase the antenna gain Antennas

The quarter wave vertical antenna requires an excellent ground system to fully utilize the

Mirror image principle Ground current principle

Troposcatter effect End effect Antennas

The radiation apttern of collinear and broadside antennas is Bidirectional Omnidirectional Unidirectional Clover-leaf shape AntennasThe radiation pattern of ______ antennas have a beamwidth of approximately 17° and are capable of covering 42% of earth s surface.

Earth coverage Spot Zonal District Antennas

The radiation pattern of earth coverage antennas have a bandwidth of approximately

17 degrees 21 degrees 5 degrees 35 degrees Antennas

The ratio of the amount of power required at the input of a theoretical loss-free reference antenna and the actual amount of power required for a signal to have the same field strength at a specific distance in a specific direction.

Antenna gain Beamwidth Bandwidth All of the above Antennas

What determines antenna polarization? The direction of the The frequency of the The direction of the The direction of the Antennas


electric field vector radiated wave radiated wave magnetic field vectorWhat do you call the single booster installed on the antenna dish of satellite receiver?

LNA Single amplifier Noise amplifier Rectifier Antennas

When the transmitting and receiving antenna are in line-of-sight of each other, the propagation mode is known as

Space wave Ground wave Sky wave Surface wave Antennas

When the transmitting and receiving antennas are line-of-sight of each other, the mode of propagation is ___ wave.

Space or direct Sky Surface Ground Antennas

When the transmitting antenna is horizontal, that antenna radiates ___ polarized waves.

Horizontally Positively Negatively Vertically Antennas

When using a microwave space diversity transmission, the two antennas must be:

Separated vertically on same tower

Separatd horizontally on same tower

Connected in series on same tower

Connected in parallel on same tower

Antennas

Where does the voltage node of a half-wave antenna exists? At feed point Near the center At center Near the feed point AntennasWhether or not polarization of an antenna is linear depends The direction of the

electric wave planeThe horizontal or vertical plane of the electric wave

The direction in which the magnetic wave is radiated

Changes in direction in which the electric plane is radiated

Antennas

Which antenna has a unidirectional radiation pattern and gain?

Yagi Ground plane Dipole Collinear Antennas

Which antenna is not properly terminated? Resonant Non-resonant Isotropic Whip AntennasWhich antenna is properly terminated? Rhombic Dipole Marconi Yagi-Uda AntennasWhich antenna radiates an omnidirectional pattern in the horizontal plane with vertical polarization?

Marconi antenna Discone antenna Horn antenna Helical antenna Antennas

Which beam width represents the best antenna directivity? 7 12 19 28 AntennasWhich does not used vertical polarization antennas? FM broadcasting AM broadcasting Mobile communications Satellite communications AntennasThe reflector and director of an antenna array are considered as

Parasitic elements Driven elements Feed-points Transcendental elements Antennas

The stability of transmitted signal from a simple Hartley oscillator single transmitter which is coupled to an antenna wire affected by

Closer coupling b/w the oscilaltor and the antenna

Chirping of oscillator and location of antenna

Material and location of antenna

None of the above Antennas


Which of the following improves antenna directivity? Parasitic element Director element Reflector element Driven element AntennasWhich of the following is a properly terminated antenna? Rhombic Dipole Hertz Marconi AntennasThis is a flexible vertical rod antenna commonly used in mobile.

Whip Marconi Hertz Ground plane Antennas

To lengthen an antenna electrically, add a Coil Battery Conduit Resistor AntennasTo match a 6 ohm amplifier impedance to a 72 ohm antenna load, a transformer must have a turn ratio Np/Ns of

0.289 0.083 3.36 12 Antennas

Top loading is used in an antenna in order to increase its Effective height Beamwidth Input capacitance Practical height AntennasTransmission lines when connected to antennas have Resistive load at

resonant frequencyCapacitive load Resistive load whose

Resistance > Zo of the lineResistive load whose resistance > Zo of the line

Antennas

Two or more antennas separated by 9 wavelengths are used. Space diversity Frequency diversity Hybrid diversity Polarized diversity AntennasTwo wires that are bent 90 degrees apart. Dipole Hertz Rhombic Yagi-Uda AntennasType of antenna which is normally used for satellite tracking service.

Helical Hertz Yagi Rhombic Antennas

Type of antenna which radiates energy equally in all direction along the horizontal plane.

Omnidirectional Bi-directional Unidirectional Fan beam Antennas

Using small reflector to beam waves to the larger parabolic reflector is known as

Cassegrain feed Horn feed Focal feed Coax feed Antennas

What ferrite device can be used instead of duplexer to isolate a microwave transmitter and receiver when both are connected to the same antenna?

Circulator Isolator Simplex Magnetron Antennas

What happens when a horn antenna is made longer? Gain increases & beam width decreases

Beam width decreases Gain increases & beam width decreases

Beam width increases Antennas

What is a radio station which provides interface between the mobile telephone switching office and the mobile radio units? It has control units, radio sets, antennas, a power source and data terminal.

Cell site Trunk site Repeater site Public telephone exchange site

Antennas

What is the bandwidth of the antenna if it has a figure of 5 MHz 0.5 MHz 15 MHz 50 MHz Antennas


merit of 80 and the operating frequency of 400 MHz.What is the capture area of a dipole operated at 75 MHz? 2.088 sq. m. 2 sq. m. 4 sq. m. 4.088 sq. m. AntennasWhat is the carrier power in the problem above if the antenna resistance is 75 ohms?

792 W 195 W 631 W 507 W Antennas

What is the effective radiated power (ERP) of a repeater with 450 watt transmitting output , 4 dB feedline loss, 6 dB duplexer loss, 7 dB circulator loss and feedline antenna gain of 25 dB

2839.24 W 2840.47 W 2836.28 W 2838.31 W Antennas

What is the EIRP in dBW of a 50 dB antenna connected to a transmitter with an output of 10 kW through a transmission ine with a loss of 5dB?

85 dBW 95 dBW 90 dBW 80 dBW Antennas

What is the ERP of a repeater with 200 W transmitter power output a 4 dB feedline loss 4 dB duplexer loss and 10 dB feedline antenna gain?

317 W 2000 W 126 W 260 W Antennas

What is the estimated medium wind loading in the Philippines for antenna tower design?

200 kph 100 kph 250 kph 300 kph Antennas

What is the free space loss, in dB, between two microwave parabolic antennas 38 kilometers apart when operating at 7.0 GHz?

140.89 138.6 143.5 145.1 Antennas

What is the front-to-back ratio of an antenna which radiates 500 watts in a northernly direction and 50 watts in southernly direction?


What is the gain of a Hertzian dipole over isotropic antenna? 1.76 dB 2.15 dB 1.64 dB 1.55 dB AntennasWhat is the gain of four identically polarized antenna stacked one above the other fed inphase?





Antennas

What is the gain of isotropic antenna? 1 10 100 50 AntennasWhat is the input impedance of a center fed dipole antenna? It differs with length 73 Ohm 300 Ohm 0 AntennasWhat is the main component of a dummy antenna? A non-inductive resistor A wire-wound resistor An iron-core coil An air-core coil Antennas


What is the minimum number of turns a helix antenna must have?

3 4 5 6 Antennas

What is the optimum length of a marconi antenna for the transmission of a 300 MHz signal? The antenna velocity factor is 0.85

0.21 m 0.22 m 0.23 m 0.24 m Antennas

What is the polarization of a discone antenna? Vertical Horizontal Circular Spiral AntennasWhat is the Q of an antenna with a bandwidth of 6 MHz and a frequency of 300 MHz?

50 0.5 5 500 Antennas

What is the radiation characteristic of a dipole antenna? Bidirectional Omnidirectional Unidirectional Hemispherical AntennasWhat is the radiation resistance of an antenna which radiates 20 kW when it draws 20 A?

50 ohms 5 ohms 5 kohms 500 ohms Antennas

What is the space wave radio horizon for an antenna whose height is 36 m?

24 km 15 km 26 km 32 km Antennas

What is the term for the ratio of the radiation resistance of an antenna to the total resistance of the system?

Antenna efficiency Effective radiated power Beamwidth Radiation conversion loss Antennas

What is the theoretical gain of a Hertzian dipole? 1.76 dB 2.15 dB 3 dB 1 dB AntennasWhat quarter wave transformer will match a 100 ohms line to an antenna whose value is 175 ohms?

132.29 ohms 150 ohms 16.58 ohms 137.5 ohms Antennas

When a microwave beam between two antennas is assumed to follow a line parallel to that of the curvature of the earth. The equivalent earth radius is equal to

Infinity 0 2/3 4/3 Antennas

When a quarterwave stub is used to match a 600 ohm antenna to a line of 52 ohms, the impedance of the matching stub must be:


When a single antenna is intended to be used both for transmitting and receiving, it is necessary to use a:

Duplexer Diplexer Multiplexer Combiner Antennas

When designing a TV antenna, a length of l/2 (lambda/2) is required. What is the antenna length in centimeters required for a radio wave with frequency of 72 MHz?

208 m 215 m 200 m 210 m Antennas


When speaking of antennas, ____ is a section which would be a complete antenna by itself.

Bay Image Top loading Quarterwave Antennas

When testing transmitter to prevent interfering with other stations, which type of antenna must be used?

Dummy antenna Void antenna Hertzian antenna End-fire array antenna Antennas

Which is a non-resonant antenna? Rhombic antenna Folded dipole End-fire array Yagi-Uda antenna AntennasWhich is properly terminated antenna? Rhombic antenna Hetrz Marconi Dipole AntennasWhich of the following antenna feedline can easiliy be buried underground for a distance without adverse effects?

Coaxial cable Waveguide Ribbon cable Microstrip Antennas

Which of the following antennas is best excited from a wave guide?

Horn Biconical Helical Discone Antennas

Which of the following antennas with similar sizes has greatest gain?

Parabolic reflector Plane reflector Corner reflector beams All of the above Antennas

Which of the following elements improves antenna directivity?

Director Dipole Reflector Driven Antennas

Which of the following is the first component of any MATV system to receive broadcast signals?

Antenna LNA Filter RF amplifier Antennas

Which of the following parts of the radio receiver represent the component that extracts the desired RF signal from the electromagnetic wave?

Antenna AF amplifier Detector Crystal Antennas

Which one of the following is considered to be a nonresonant antenna?

Rhombic antenna Folded dipole Broadside array antenna End-fire aray antenna Antennas

Why should we regularly clean, resolder and tighten all antenna connectors?

To help keep their resistance at a minimum

To keep looking nice To keep them from getting stuck in place

To increase their capacitance

Antennas

Zoning is used with a dielectric antenna in order to Reduce the bulk of the lens

Increase the bandwidth of the lens

Permit pin-point focusing Correct the curvature of the wavefront from a horn that is too short

Antennas

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Antennas.docx