flashcard 3

Front

What is multipath in radio channels?

Back

Multipath refers to the phenomenon where signals arrive at the receiver via multiple paths due to reflections, scattering, and diffraction, leading to effects like time dispersion and rapid changes in signal strength.

Front

What is the primary characteristic of first-generation wireless systems?

Back

First-generation wireless systems are characterized by low data rates and primarily use analog technology.

Front

What is the output impedance of FETs compared to BJTs?

Back

FETs have a higher input impedance and lower output impedance compared to BJTs, making them more suitable for input stages.

Front

What is the frequency domain representation of a periodic triangular function?

Back

The frequency domain of a periodic triangular function is represented as a continuous sampling square function.

Front

What is a Ripple-carry adder?

Back

A Ripple-carry adder is a digital logic circuit that can add multiple bits simultaneously by carrying the overflow from one bit to the next.

Front

Define 'Random frequency modulation' in the context of radio channels.

Back

Random frequency modulation refers to the variation in frequency of a signal due to multipath effects, which can lead to distortion and interference.

Front

What does 'Time dispersion' mean in radio communication?

Back

Time dispersion is the spreading of a signal in time due to multipath propagation, causing delays and potential overlap of signals.

Front

What are the limitations of first-generation wireless systems?

Back

First-generation wireless systems are limited by low data rates, analog technology, and lack of advanced features like digital encryption.

Front

Explain the significance of output impedance in FETs.

Back

The lower output impedance of FETs allows for better signal integrity and less loading on the previous stage, making them ideal for input applications.

Front

What is the difference between a Full-adder and a Ripple-carry adder?

Back

A Full-adder adds two bits and a carry-in, while a Ripple-carry adder can add multiple bits by chaining several Full-adders together.