Podcast
Questions and Answers
What is the main reason that the polarization of waves changes during transmission over long distances?
What is the main reason that the polarization of waves changes during transmission over long distances?
- Various propagation effects in free space cause the polarization to change (correct)
- The wavelength of the signal changes over long distances
- The conductor length is not properly matched to the frequency
- The shape of the antenna changes over long distances
What is the most common length for antennas in terms of the wavelength of the transmitted signal?
What is the most common length for antennas in terms of the wavelength of the transmitted signal?
- Three-quarters wavelength
- Two wavelengths
- One-eighth wavelength
- One-half wavelength (correct)
What is the wavelength of a 3-kHz audio signal?
What is the wavelength of a 3-kHz audio signal?
- $30,000$ m
- $100,000$ m (correct)
- $300,000$ m
- $3,000$ m
What is the main reason that little radiation occurs with a signal carried by a cable or transmission line?
What is the main reason that little radiation occurs with a signal carried by a cable or transmission line?
How can an open transmission line be made into an antenna?
How can an open transmission line be made into an antenna?
What is the primary characteristic of the radiation pattern of most antennas?
What is the primary characteristic of the radiation pattern of most antennas?
What type of wave do most wireless applications use?
What type of wave do most wireless applications use?
In which field are measurements valid for antenna radiation patterns?
In which field are measurements valid for antenna radiation patterns?
What is the significance of polarization in antennas?
What is the significance of polarization in antennas?
What type of wave will a vertically polarized antenna produce 0 V in?
What type of wave will a vertically polarized antenna produce 0 V in?
Why is it important for both transmitting and receiving antennas to be of the same polarization?
Why is it important for both transmitting and receiving antennas to be of the same polarization?
Which type of antennas produce horizontal polarization?
Which type of antennas produce horizontal polarization?
What causes the generation of a sinusoidal magnetic field?
What causes the generation of a sinusoidal magnetic field?
What is the ratio of the electric field strength to the magnetic field strength in a radiated wave called?
What is the ratio of the electric field strength to the magnetic field strength in a radiated wave called?
What is the value of the wave impedance mentioned in the text?
What is the value of the wave impedance mentioned in the text?
At what speed are the resulting fields radiated into space?
At what speed are the resulting fields radiated into space?
What component of an antenna does not dissipate power in the form of heat?
What component of an antenna does not dissipate power in the form of heat?
What describes the region directly around the antenna where the electric and magnetic fields are distinct?
What describes the region directly around the antenna where the electric and magnetic fields are distinct?
What is the main purpose of a parasitic array?
What is the main purpose of a parasitic array?
Which of the following statements about reflectors in a parasitic array is true?
Which of the following statements about reflectors in a parasitic array is true?
How do directors in a parasitic array contribute to the radiation pattern?
How do directors in a parasitic array contribute to the radiation pattern?
What is the typical configuration of the driven element in a parasitic array?
What is the typical configuration of the driven element in a parasitic array?
What is the approximate spacing between the directors and the driven element in a parasitic array?
What is the approximate spacing between the directors and the driven element in a parasitic array?
Which of the following statements about parasitic elements is false?
Which of the following statements about parasitic elements is false?
What type of transmission line is ideal for a dipole antenna?
What type of transmission line is ideal for a dipole antenna?
How is the Marconi or ground-plane vertical antenna fed?
How is the Marconi or ground-plane vertical antenna fed?
What role does the earth ground play in a Marconi antenna setup?
What role does the earth ground play in a Marconi antenna setup?
At very high frequencies, what can serve as an effective ground plane for antennas?
At very high frequencies, what can serve as an effective ground plane for antennas?
What is the impedance of a vertical ground-plane antenna compared to a dipole?
What is the impedance of a vertical ground-plane antenna compared to a dipole?
How does the actual impedance of a vertical ground-plane antenna vary?
How does the actual impedance of a vertical ground-plane antenna vary?
