gacon149
06-09-2008, 01:26
Mình đang học môn Antenna ở trường, thiệt là bực mình quá đi mất,mình rất dốt môn Tiếng Anh.Vì vậy không thể làm bài tập được.Mặc dù đã rất cố gắng, mong các bạn thông cảm và tận tâm giúp đỡ!!!!!!!!!!!!!!!!!!!!!
1, How should a transmitting antenna be designed if a vertically polarized wave is to be radiated, and how should the receiving antenna be designed for best performance in receiving the ground wave from this transmitting antenna.?
2, If a field intensity of 25 mV/m develops 2.7V in a certain antenna, what is its effective height?
3, if a power of a 500-kHz transmitter is increased from 150W to 300W, what would be the percentage change in field intensity at a given distance from the transmitter? What would be the decibel change in field intensity?
4, If a 500kHz transmitter of constant power produces a field strength of 100 V/m at a distance of 100 mile from the transmittion, what would be the theoretical field strength at a distance of 200 mile from the transmitter?
5, If the antenna current at a 500kHz transmitter is reduced 50%, what would be the percentage change in the field intensity at the receiving point?
6, Define field indensity. Explain how it is measured.
7, Define polarization as it refers to broadcast antennas.
8, Draw a diagram showing how current varies along a half- wavelength Hertz antenna.
9, Can either of the two fields that emanate from an antenna produce an EMF in a receiving antenna?If so, how?
10, What is the effective radiated power of a television broadcast station if the output of transmitter is 1000W, antenna transmission line loss is 50W, and the antenna power gain is 3?
11, Draw the three- dimensional radiation pattern for the Hertz antenna, and explain how it is developed.
12, Explain the following terms with respect to antennas (transmittion or reception):
A, Field strength.
B, power gain.
C, Physical length.
D, Electrical length.
E, Polarization.
F, Diversity reception.
G, Corona discharge.
Các bạn có thể liên lạc với mình qua Email: phuong_nam_kt2003@yahoo.com
THANKYOU for writing!!!!!!!
1, How should a transmitting antenna be designed if a vertically polarized wave is to be radiated, and how should the receiving antenna be designed for best performance in receiving the ground wave from this transmitting antenna.?
2, If a field intensity of 25 mV/m develops 2.7V in a certain antenna, what is its effective height?
3, if a power of a 500-kHz transmitter is increased from 150W to 300W, what would be the percentage change in field intensity at a given distance from the transmitter? What would be the decibel change in field intensity?
4, If a 500kHz transmitter of constant power produces a field strength of 100 V/m at a distance of 100 mile from the transmittion, what would be the theoretical field strength at a distance of 200 mile from the transmitter?
5, If the antenna current at a 500kHz transmitter is reduced 50%, what would be the percentage change in the field intensity at the receiving point?
6, Define field indensity. Explain how it is measured.
7, Define polarization as it refers to broadcast antennas.
8, Draw a diagram showing how current varies along a half- wavelength Hertz antenna.
9, Can either of the two fields that emanate from an antenna produce an EMF in a receiving antenna?If so, how?
10, What is the effective radiated power of a television broadcast station if the output of transmitter is 1000W, antenna transmission line loss is 50W, and the antenna power gain is 3?
11, Draw the three- dimensional radiation pattern for the Hertz antenna, and explain how it is developed.
12, Explain the following terms with respect to antennas (transmittion or reception):
A, Field strength.
B, power gain.
C, Physical length.
D, Electrical length.
E, Polarization.
F, Diversity reception.
G, Corona discharge.
Các bạn có thể liên lạc với mình qua Email: phuong_nam_kt2003@yahoo.com
THANKYOU for writing!!!!!!!