Radio Frequency Part 1

What is frequency?

Rate which current changes direction per second. Measured in Hz

What is amplitude?

The signals strength

What is wavelength?

Describes how long the wave is. Measured in meters

What is phase?

The relationship between two or more signals that share the same frequency

What are the three types of modulation?

1. Amplitude

2. Frequency

3. Phase shift

What is amplitude modulation?

The amplitude of the signal is altered

What is frequency modulation?

The frequency of the signal is altered

What is modulation?

Manipulates the RF signal to meet communication requirements

What is phase shift keying?

Alters the phase

What are the advantages of AM?

1. Simple to implement

2. Can be demodulated with ease

3. Receivers are very cheap

What are the disadvantages of AM?

1. Inefficient power usage

2. Inefficient use of bandwidth

3. Prone to high levels of noise

What are the advantages of FM?

1. Resilient to noise and interference

2. Easy to apply modulation at low power stage of the transmitter

3. Power efficient so less battery power is required

What are the disadvantages of FM?

1. Poor spectrum efficiency

2. Complicated circuits

3. Some modes have higher spectrum requirements

What are the three radio frequency equipment components?

1. Transmitter

2. Receiver

3. Transceiver

What is a transmitter?

Generate a radio frequency

What is a reciever?

Recover the intelligence sent from a transmitter

What is a transceiver?

Combines the transmitter and receiver

What is the relationship between frequency and wavelength?

They are inversely related.

What is the relationship between frequency and antenna size?

Higher frequency usually means a smaller antenna

What is the component of the transmitter that creates the carrier wave?

The Oscillator

Which component of the receiver recovers intelligence from the receive signal?

The modulator