Modern Electronic Communication by Gary Miller Chapter 13 with Answers

Chapter 13 Antennas

1	The process of interchangeability of receiving and transmitting operations of antennas is known as
	a. Polarization
	b. Reciprocity
	c. Efficiency
	d. Counterpoise
2	A half-wave dipole antenna is also known as
	a. Marconi antenna
	b. Hertz antenna
	c. Vertical antenna
	d. Phased array
3	An antenna that is a quarter-wavelength long connected such that the ground acts as a reflecting quarter-wavelength section is called a
	a. Hertz antenna
	b. Dipole antenna
	c. Marconi antenna
	d. All the above
4	The angular separation between the half-power points on an antenna's radiation pattern is the
	a. Bandwidth
	b. Front-to-back ratio
	c. Lobe distribution
	d. Beamwidth
5	The input impedance at the center of a dipole antenna is approximately
	a. 36.6
	b. 50
	c. 73
	d. 300
6	As the height of a half-wavelength antenna is reduced below a quarter-wavelength, the radiation resistance
	a. Increases
	b. Decreases
	c. Remains the same
	d. All the above
7	A dipole antenna is being fed with a 300 transmission line. If a quarter-wave matching transformer is to be used as the non-resonant matching section, what must be the characteristic impedance of the cable used in the matching transformer?
	a. 186.5
	b. 103.9
	c. 122.5
	d. 147.9
8	An impedance-matching device that spreads the transmission line as it approaches the antenna is called a
	a. Delta match
	b. Quarter-wave matching device
	c. Director
	d. Counterpoise
9	A loading coil is often used with a Marconi antenna in order to
	a. Tune out the capacitive reactance portion of the input impedance of the antenna
	b. Tune out the inductive reactance portion of the input impedance of the antenna
	c. Raise the input impedance of the antenna
	d. Decrease the losses of the antenna
10	Standard AM broadcast stations usually use what type of transmitting antennas?
	a. Driven collinear array
	b. Marconi array
	c. Yagi-Uda
	d. Log-periodic
11	The type of antenna often found in small AM broadcast receivers is a
	a. Ferrite loop antenna
	b. Folded dipole antenna
	c. Slot antenna
	d. Log-periodic antenna
12	The folded dipole antenna has
	a. Greater bandwidth than a half-wave dipole
	b. A 288- input impedance
	c. Less bandwidth than a half-wave dipole
	d.. a and b
	e. b and c
13	The Yagi-Uda antenna consists of
	a. A driven director and parasitic reflector
	b. A driven reflector and parasitic director
	c. A parasitic director and reflector
	d. All the above
14	A grid-dip meter measures the resonant frequency of tuned circuits
	a. By connection in series with the inductance
	b. By connection in parallel with the inductance
	c. Without power being applied to the tuned circuit
	d. By connection in series with the capacitance
15	When troubleshooting antennas, the level of VSWR that indicates a problem is
	a. Greater than 1
	b. Less than 1
	c. Greater than 1.5
	d. Less than 0.5

Answers:

B

B

C

D

C

B

D

A

A

B

A

D

C

C

C