007 - Feedlines - Matching and Antenna Systems Flashcards
A-007-001-001
For an antenna tuner of the “Transformer” type, which of the following statements is FALSE?
(a) The input is suitable for 50 ohm impedance
(b) The output is suitable for impedances from low to high
(c) The circuit is known as a transformer-type antenna tuner
(d) The circuit is known as a Pi-type antenna tuner
A-007-001-001
For an antenna tuner of the “Transformer” type, which of the following statements is FALSE?
(d) The circuit is known as a Pi-type antenna tuner
A-007-001-002
For an antenna tuner of the “Series” type, which of the following statements is false?
(a) The circuit is known as a Pi-type antenna tuner
(b) The circuit is known as a Series-type antenna tuner
(c) The output is suitable for impedances from low to high
(d) The input is suitable for impedance of 50 ohms
A-007-001-002
For an antenna tuner of the “Series” type, which of the following statements is false?
(a) The circuit is known as a Pi-type antenna tuner
A-007-001-003
For an antenna tuner of the “L” type, which of the following statements is false?
(a) The transmitter input is suitable for 50 ohms impedance
(b) The antenna output is high impedance
(c) The circuit is suitable for matching to a vertical ground plane antenna
(d) The circuit is known as an L-type antenna tuner
A-007-001-003
For an antenna tuner of the “L” type, which of the following statements is false?
(c) The circuit is suitable for matching to a vertical ground plane antenna
A-007-001-004
For an antenna tuner of the “Pi” type, which of the following statements is false?
(a) The circuit is a series-type antenna tuner
(b) The transmitter input is suitable for impedance of 50 ohms
(c) The antenna output is suitable for impedances from low to high
(d) The circuit is a Pi-type antenna tuner
A-007-001-004
For an antenna tuner of the “Pi” type, which of the following statements is false?
(a) The circuit is a series-type antenna tuner
A-007-001-005
What is a pi-network?
(a) An antenna matching network that is isolated from ground
(b) A network consisting of four inductors or four capacitors
(c) A network consisting of one inductor and two capacitors or two inductors and one capacitor
(d) A power incidence network
A-007-001-005
What is a pi-network?
(c) A network consisting of one inductor and two capacitors or two inductors and one capacitor
A-007-001-006
Which type of network offers the greatest transformation ratio?
(a) Chebyshev
(b) Butterworth
(c) L-network
(d) Pi-network
A-007-001-006
Which type of network offers the greatest transformation ratio?
(d) Pi-network
A-007-001-007
Why is an L-network of limited utility in impedance matching?
(a) It is thermally unstable
(b) It matches only a small impedance range
(c) It is prone to self-resonance
(d) It has limited power handling capability
A-007-001-007
Why is an L-network of limited utility in impedance matching?
(b) It matches only a small impedance range
A-007-001-008
How does a network transform one impedance to another?
(a) It produces transconductance to cancel the reactive part of an impedance
(b) It cancels the reactive part of an impedance and changes the resistive part
(c) It introduces negative resistance to cancel the resistive part of an impedance
(d) Network resistances substitute for load resistances
A-007-001-008
How does a network transform one impedance to another?
(b) It cancels the reactive part of an impedance and changes the resistive part
A-007-001-009
What advantage does a pi-L network have over a pi-network for impedance matching between a vacuum tube linear amplifier and a multiband antenna?
(a) Greater harmonic suppression
(b) Higher efficiency
(c) Lower losses
(d) Greater transformation range
A-007-001-009
What advantage does a pi-L network have over a pi-network for impedance matching between a vacuum tube linear amplifier and a multiband antenna?
(a) Greater harmonic suppression
A-007-001-010
Which type of network provides the greatest harmonic suppression?
(a) Inverse pi-network
(b) Pi-network
(c) Pi-L network
(d) L-network
A-007-001-010
Which type of network provides the greatest harmonic suppression?
(c) Pi-L network
A-007-001-011
A Smith Chart is useful:
(a) because it simplifies mathematical operations
(b) only to solve matching and transmission line problems
(c) to solve problems in direct current circuits
(d) because it only works with complex numbers
A-007-001-011
A Smith Chart is useful:
(a) because it simplifies mathematical operations
A-007-002-001
What kind of impedance does a quarter wavelength transmission line present to the source when the line is shorted at the far end?
(a) The same as the characteristic impedance of the transmission line
(b) The same as the output impedance of the source
(c) A very high impedance
(d) A very low impedance
A-007-002-001
What kind of impedance does a quarter wavelength transmission line present to the source when the line is shorted at the far end?
(c) A very high impedance
A-007-002-002
What kind of impedance does a quarter wavelength transmission line present to the source if the line is open at the far end?
(a) A very low impedance
(b) A very high impedance
(c) The same as the output impedance of the source
(d) The same as the characteristic impedance of the transmission line
A-007-002-002
What kind of impedance does a quarter wavelength transmission line present to the source if the line is open at the far end?
(a) A very low impedance
A-007-002-003
What kind of impedance does a half wavelength transmission line present to the source when the line is open at the far end?
(a) The same as the characteristic impedance of the transmission line
(b) A very high impedance
(c) The same as the output impedance of the source
(d) A very low impedance
A-007-002-003
What kind of impedance does a half wavelength transmission line present to the source when the line is open at the far end?
(b) A very high impedance
A-007-002-004
What kind of impedance does a half wavelength transmission line present to the source when the line is shorted at the far end?
(a) A very high impedance
(b) The same as the characteristic impedance of the transmission line
(c) The same as the output impedance of the source
(d) A very low impedance
A-007-002-004
What kind of impedance does a half wavelength transmission line present to the source when the line is shorted at the far end?
(d) A very low impedance
A-007-002-005
What is the velocity factor of a transmission line?
(a) The velocity of the wave on the transmission line multiplied by the velocity of light in a vacuum
(b) The index of shielding for coaxial cable
(c) The velocity of the wave on the transmission line divided by the velocity of light
(d) The ratio of the characteristic impedance of the line to the terminating impedance
A-007-002-005
What is the velocity factor of a transmission line?
(c) The velocity of the wave on the transmission line divided by the velocity of light
A-007-002-006
What is the term for the ratio of the actual velocity at which a signal travels through a transmission line to the speed of light in a vacuum?
(a) Velocity factor
(b) Characteristic impedance
(c) Surge impedance
(d) Standing wave ratio
A-007-002-006
What is the term for the ratio of the actual velocity at which a signal travels through a transmission line to the speed of light in a vacuum?
(a) Velocity factor
A-007-002-007
What is a typical velocity factor for coaxial cable with polyethylene dielectric?
(a) 0.33
(b) 0.1
(c) 2.7
(d) 0.66
A-007-002-007
What is a typical velocity factor for coaxial cable with polyethylene dielectric?
(d) 0.66
A-007-002-008
What determines the velocity factor in a transmission line?
(a) The line length
(b) The centre conductor resistivity
(c) Dielectrics in the line
(d) The terminal impedance
A-007-002-008
What determines the velocity factor in a transmission line?
(c) Dielectrics in the line
A-007-002-009
Why is the physical length of a coaxial cable shorter than its electrical length?
(a) RF energy moves slower along the coaxial cable than in air
(b) The surge impedance is higher in the parallel transmission line
(c) Skin effect is less pronounced in the coaxial cable
(d) The characteristic impedance is higher in a parallel transmission line
A-007-002-009
Why is the physical length of a coaxial cable shorter than its electrical length?
(a) RF energy moves slower along the coaxial cable than in air
A-007-002-010
The reciprocal of the square root of the dielectric constant of the material used to separate the conductors in a transmission line gives the ____________ of the line:
(a) VSWR
(b) velocity factor
(c) impedance
(d) hermetic losses
A-007-002-010
The reciprocal of the square root of the dielectric constant of the material used to separate the conductors in a transmission line gives the ____________ of the line:
(b) velocity factor
A-007-002-011
The velocity factor of a transmission line is the:
(a) impedance of the line, e.g. 50 ohm, 75 ohm, etc.
(b) ratio of the velocity of propagation in the transmission line to the velocity of propagation in free space
(c) speed at which the signal travels in free space
(d) speed to which the standing waves are reflected back to the transmitter
A-007-002-011
The velocity factor of a transmission line is the:
(b) ratio of the velocity of propagation in the transmission line to the velocity of propagation in free space
A-007-003-001
What term describes a method used to match a high-impedance transmission line to a lower impedance antenna by connecting the line to the driven element in two places, spaced a fraction of a wavelength on each side of the driven element centre?
(a) The gamma match
(b) The omega match
(c) The T match
(d) The stub match
A-007-003-001
What term describes a method used to match a high-impedance transmission line to a lower impedance antenna by connecting the line to the driven element in two places, spaced a fraction of a wavelength on each side of the driven element centre?
(c) The T match
A-007-003-002
What term describes an unbalanced feed system in which the driven element of an antenna is fed both at the centre and a fraction of a wavelength to one side of centre?
(a) The omega match
(b) The stub match
(c) The T match
(d) The gamma match
A-007-003-002
What term describes an unbalanced feed system in which the driven element of an antenna is fed both at the centre and a fraction of a wavelength to one side of centre?
(d) The gamma match