PC1: RF Principles and Signal Characteristics Flashcards
What is static electricity?
- The separation of charges
- Opposite charges attract and like charges repel each other
What is magnetism?
The force exerted by magnets when they attract or repel each other
You cannot have a magnetic field without what?
An electric field
An electric field must always create what?
A magnetic field
Magnetic fields flow which way?
North to south
Coulomb’s Law is also know as what?
Inverse Square Law
What is Coulomb’s Law?
The force is inversely proportional to the square of the distance between the charges
What is the bottom line between electricity and magnetism?
They are the same force operating in different ways
What kind of current creates waves?
Alternating Current (AC)
What is the flow of energy (photons) at the speed of light through free space or through a material medium in the form of electric and magnetic fields that make up electromagnetic waves?
Electromagnetic (EM) Radiation
What produces an oscillating e-field and b-field?
Eletromagnetic (EM) Radiation
What did Young’s Double Slit Experiment demonstrate?
Light’s constructive and destructive behaviors
What did Young’s Double Slit Experiment prove?
Light exibits properties of waves
What is a sine wave?
Simply a continuous, uniform wave with a constant frequency, amplitude, and phase
How is amplitude measured?
From the zero point on an x-axis to the top of the highest point of the wave
What does amplitude represent?
Power
How is wavelength measured?
The distance between the two highest points between waves
Measured peak to peak or trough to trough
How is frequency measured?
Number of cycles per second using Hertz (Hz)
What is the relationship between wavelength and frequency?
Inversely proportional
Ex. the shorter the wavelength, the greater the frequency
What is the relationship between energy and frequency?
Directly proportional
Ex. The greater the frequency, the higher the energy
How is phase measured?
Offset from the baseline wave using degrees
What is polarization?
Orientation of a wave, typically from the e-field perspective
What are two types of polarization?
- Linear
- Circular
What frequency is affected most by scintillation?
Low
What is an atmospheric window?
Regions of the EM spectrum where energy can be fully transmitted without interference
What band does the military like to operate in and why?
X band because of the balance between scintillation and atmospheric effects
