wireless systems in which the EM waves are emitted then radiated through air, water, and vacuum. (Earth’s atmosphere, free space)

used as a transmission line between antenna and transmitter or antenna and receiver

The same as the two-wire open line, except that uniform spacing is assured by embedding the two wires in a low-loss dielectric, usually polyethylene

consist of parallel conductors separated from each other, and surrounded by a dielectric. The copper braid/foil serves as a shield.

used primarily on computer networks (LAN). CAT6 and CAT5e with data rates of 1000Mbps in a max length of 100m

Consists of a wire mounted inside, and coaxially with, a tubular outer conductor. Used to minimize radiation losses. The spacers or beads are made of Pyrex, polystyrene, or some material with good insulation and low loss at high frequencies.

Concentric cables are also made, with the inner conductor consisting of flexible wire insulated from the outer conductor by a solid, continuous insulating material. Flexibility may be gained if the outer conductor is made of braided wire, although this reduces the level of shielding.

They are copper patterns in PCB

The ground plane of microstrip must be at least ________ times wider than the top conductor and must be connected to the ground.

Generally its length is ______ or_______ wavelength of the frequency of operation and equivalent to an unbalanced.

means the same amount of current flows in each wire with reference to ground

The direction of the current in one wire is 180 degrees out of phase with the current in the another wire.

consist of one for the signal and the other for the reference. The wire used for reference is typically the ground and can be used as a shield against interference, i.e. noise. Suffer from more problems with noise An example is coaxial cable.

A small transformer used to convert from an unbalanced to a balanced signal and vice versa

These are cables coated with low-smoke and fire-resistant jackets instead of PVC.

They are used to comply with building and fire-safety standards in building construction.

sometimes called as conductor heating loss or the I2R loss.

directly proportional to the squared of the transmission line length.

the tendency of the AC current to flow in concentration around the outer “skin” of the conductor

this is due to the difference in potential between the 2 conductors.

the electrostatic and electromagnetic fields that surrounds the conductor cause the line to act as an antenna and transfer energy to any nearby conductive material. This can be reduced by shielding.

occurs whenever a connection is made to or from a transmission line or when two separate pieces of transmission line are connected together

a luminous discharge that occurs between the two conductors of a transmission line when the difference of potential between them exceeds the breakdown voltage of the dielectric.

the impedance of the transmission line measured from the input or output provided that the length of the transmission line is infinite.

also called surge impedance

the particles of the medium vibrate in a direction perpendicular to the direction of propagation of the wave

the particles of the medium vibrate in a direction parallel to the direction of propagation of the wave

the number of complete cycle or alternations per unit time

the distance between the two crests or trough or the distance which the wave’s shape repeats

the maximum displacement or distance measured from its equilibrium position.

Transmission media lie below the __________ layer.

_________ cable consists of an inner copper core and a second conducting outer sheath.

__________ consists of a central conductor and a shield.

_______ cable can carry signals of higher frequency ranges than _______ cable.

_________ are used for cellular phone, satellite, and wireless LAN communications.

The inner core of an optical fiber is _________ in composition.

What is the major factor that makes coaxial cable less susceptible to noise than twisted-pair cable?

Signals with a frequency below 2 MHz use _______ propagation.

In an optical fiber, the inner core is _________ the cladding

________ cable consists of two insulated copper wires twisted together.

In fiber optics, the signal is __________ waves.

Signals with a frequency above 30 MHz use _______propagation.

A(n) _______ medium provides a physical conduit from one device to another.

________ cable is used for voice and data communications.

Transmission media are usually categorized as ___________.

________ are used for short-range communications such as those between a PC and a peripheral device.

_________ media transport electromagnetic waves without the use of a physical conductor

________ cables are composed of a glass or plastic inner core surrounded by cladding, all encased in an outside jacket.

When analyzing a transmission line, its inductance and capacitance are considered to be:

As frequency increases, the resistance of a wire:

The effect of frequency on the resistance of a wire is called:

As frequency increases, the loss in a cable’s dielectric:

The characteristic impedance of a cable depends on:

For best matching, the load on a cable should be:

A positive voltage pulse sent down a transmission line terminated in a short-circuit:

Indicate the false statement. The SWR on a transmission line is infinity; the line is terminated in

A (75 – j50)-Ω is connected to a coaxial transmission line of ZO = 75 Ω, at 10 GHz. The best method of matching consists in connecting

The velocity factor of a transmission line

Impedance inversion may be obtained with

Short-circuited stubs are preferred to open-circuited stubs because the latter are

For transmission-line load matching over a range of frequencies, it is best to use a

To couple a coaxial line to a parallel-wire line, it is best to use a

Indicate the three types of transmission line energy losses.

Indicate the true statement below. The directional coupler is

Radio waves were first predicted mathematically by

Radio waves were first demonstrated experimentally by

The technology that made cell phones practical was

Cell phones reduce much of the problems of mobile communications with

Which of the following are electromagnetic

The electric and magnetic fields of a radio wave are

TEM stands for:

In free space, radio waves travel at a speed of:

Which is a possible polarization for an electromagnetic wave

Which polarization can be reasonably well received by a circularly polarized antenna

The number of circular polarization modes (directions) is

An antenna has "gain" as compared to:

EIRP stands for

The "attenuation of free space" is due to:

Ground waves are most effective:

Radio waves would most strongly reflect off:

Radio waves sometimes "bend" around a corner because of:

Space waves are:

Sky waves:

Sky waves cannot be "heard":

A 20-dB reduction in the strength of a radio wave due to reflection is called:

"Ghosts" on a TV screen are an example of

A "repeater" is used to:

Cellular phone systems rely on:

are the highest-energy electromagnetic waves and able to penetrate matter easily. They have the shortest wavelengths and highest frequencies.

radiation is the next highest-energy. It may be produced by very hot bodies, such as the sun.

is the only electromagnetic radiation that is visible to our eyes

may be produced by any hot bodies similar to white light, but with longer wavelengths.

is generated by special electronic devices known as klystron valves

have the longest wavelengths, varying from a few centimeters to thousands of meters

Any conducting surface acts like a mirror to radio waves

A perfect conductor would cause a total

The bending of a wave due to the physical makeup of the medium through which the wave passes

The bending of waves around an object

is simply the orientation of the electric field vector in respect to the surface of the Earth. (looking into the horizon)

the rate at which the energy passes through a given surface area in free space

the intensity of electric and magnetic fields propagating in free space

– a point source that radiates power at constant rate uniformly in all directions

the spread out, resulting in the reduction in power density and occurs in free space as well as the Earth’s atmosphere.

is the reduction in power density in a freespace or near vacuum condition

is the reduction in power density due to non freespace propagation like the Earth’s atmosphere.

EM waves traveling within the Earth’s atmosphere

Earth-guided EM wave that travels over the surface of the Earth.

Losses is significantly high with increasing frequency

The propagation is direct from the transmitting to the receiving antenna and does not travel along the ground

Radio Horizon is about ________ greater than the geometric/optical line of sight because of diffraction effects.

are those waves radiated from the transmitting antenna in a direction that produces a large angle with respect to the Earth

are those waves radiated from the transmitting antenna in a direction that produces a large angle with respect to the Earth

The refracting and reflecting action of the ionosphere and the ground is called

This layer has the ability to refract signals of low frequencies

Also known the Kennelly–Heaviside layer because these two men were the first to propose its existence. Can refract signals with frequencies as high as 20 MHz

Responsible for high-frequency, long-distance transmission as the result of refraction for frequencies up to 30 MHz

highest frequency that is returned to Earth when transmitted vertically under given Ionospheric conditions

highest angle at which a wave of a specific frequency can be propagated and still be returned (refracted) from the ionosphere

comprising two or more receiving antennas separated by 50 wavelengths or more. The bestreceived signal at any instant is selected as input for the receiver

transmission of the same information on slightly different frequencies. The different frequencies fade independently even when transmitted and received through the same antennas.

transmission of information at two or more slightly different angles. This results in two or more paths based on illuminating different scattering volumes in the troposphere.

the capability of receiving horizontally and vertically polarized signals.