Name: circuit gain and phase shift
Uploaded: 2024-07-08T13:20:02.000Z
Duration: 1 min 15 s
Channel: JoVE

En los sistemas de comunicación, la ganancia cuantifica el grado de amplificación o atenuación de la señal.
La ganancia de potencia denota el logaritmo común de la relación entre la potencia de salida y la potencia de entrada y se expresa en bels.
Para mediciones prácticas, se usa comúnmente un decibelio. Es una subunidad equivalente a un décimo de un bel.
Considere una red con voltajes y resistencias de entrada y salida. Si la potencia de salida es igual a la potencia de entrada en esta red, la ganancia es de cero decibelios.
Cuando la potencia de salida se convierte en el doble de la potencia de entrada, la ganancia es de tres decibelios. Por el contrario, si la potencia de salida cae a la mitad de la potencia de entrada, la ganancia es de menos tres decibelios.
Alternativamente, la potencia se puede representar mediante voltaje y resistencia.
Las reglas de los logaritmos se aplican para obtener una expresión de ganancia de potencia en términos de las relaciones de voltaje y resistencia.
Cuando la resistencia de entrada es igual a la resistencia de carga, la ganancia se vuelve proporcional a la relación de voltaje de salida y entrada.
Del mismo modo, la ganancia se puede representar en términos de las relaciones de corriente y resistencia.

respuesta de frecuencia

La ganancia y el cambio de fase son propiedades de los circuitos lineales que describen el efecto que tiene un circuito sobre un voltaje o corriente de entrada sinusoidal. El comportamiento del circuito que contiene elementos reactivos dependerá de la frecuencia de la sinusoide de entrada. Como resultado, se observa que la ganancia y el cambio de fase serán funciones de frecuencia.
Ganar:
Supongamos que V_in es la entrada y V_out es la señal de salida a un circuito.
<img alt="Equation 1" src="/files/ftp_upload/15139/15139_Equation_1.svg" style="height: 20px;">
<img alt="Equation 2" src="/files/ftp_upload/15139/15139_Equation_2.svg" style="height: 16px;">
Las señales de entrada y salida tienen amplitud A y B y un ángulo de fase de 0° y θ°, respectivamente.
La ganancia del circuito da la relación entre los tamaños de las sinusoides de entrada y salida. En particular, la ganancia (K) es la relación entre la amplitud de la sinusoide de salida y la amplitud de la sinusoide de entrada.
<img alt="Equation 3" src="/files/ftp_upload/15139/15139_Equation_3.svg" style="height: 28px;">
Cuando la ganancia K es mayor que la unidad, implica amplificación, mientras que una ganancia menor que uno indica atenuación. La ganancia se describe mediante una escala logarítmica. Cuando se expresa en decibelios (dB), la ganancia proporciona una manera conveniente de representar números muy grandes y muy pequeños en la misma escala. La ganancia en decibelios se calcula mediante la fórmula:
<img alt="Equation 4" src="/files/ftp_upload/15139/15139_Equation_4.svg" style="height: 15px;">
Dónde:
dB es la ganancia en decibeles,
K es la ganancia,
log es el logaritmo en base 10.
Cambio de fase:
El cambio de fase se refiere a la cantidad en la que la fase de la señal de salida se retrasa o avanza en comparación con la fase de la señal de entrada. Es la diferencia angular entre las sinusoides de salida y entrada. La señal de entrada y salida tiene un ángulo de fase de 0° y θ° respectivamente, entonces el desplazamiento de fase (θ_shift) viene dado por:
<img alt="Equation 5" src="/files/ftp_upload/15139/15139_Equation_5.svg" style="height: 18px;">
Un desplazamiento θ positivo indica que la señal de salida está retrasada con respecto a la señal de entrada, mientras que un desplazamiento negativo significa que la señal de salida, adelanta a la señal de entrada.

Respuesta de frecuencia

En los sistemas de comunicación, la ganancia cuantifica el grado de amplificación o atenuación de la señal.
La ganancia de potencia denota el logaritmo común de la relación ...

Education

Educación

JoVE Core

Electrical Engineering

Ingeniería Eléctrica

Unit 1

Unidad 1

Frequency Response

Respuesta en frecuencia

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

Gain

circuit gain and phase shift

Circuit gain and phase shift describe how a linear circuit changes a sinusoidal input voltage or current. These properties matter in circuits with reactive elements, because the response depends on the input frequency. As the frequency changes, the gain and phase shift also change.

Gain compares the size of the output sinusoid to the size of the input sinusoid. If Vin is the input and Vout is the output, the gain K is the ratio of the output amplitude to the input amplitude. A gain greater than one means the circuit amplifies the signal, while a gain less than one means the circuit attenuates it.

Gain is often written on a logarithmic scale. When gain is expressed in decibels, or dB, it gives a practical way to show very large and very small values on the same scale. The dB value is found from the gain K using a base-10 logarithm.

Phase shift describes how much the output waveform is delayed or advanced compared with the input waveform. It is the angular difference between the input and output sinusoids. If the input has a phase angle of 0° and the output has a phase angle of θ°, then the phase shift is θ shift.

A positive phase shift means the output lags behind the input. A negative phase shift means the output leads the input. Together, gain and phase shift show both the size change and the timing change caused by a linear circuit.

Circuit Gain and Phase Shift

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key terms and concepts

Learn how linear circuits change sinusoidal signals through gain and phase shift, including amplitude ratio, decibels, and lag or lead.

Circuit Gain and Phase Shift | JoVE K12

JoVE Core Electrical Engineering offers easy-to-understand animated videos that cover fundamental concepts of electric circuits along with circuit analysis techniques. It incorporates first-order and second-order circuits using operational amplifiers and circuit transformation concepts. The inclusion of practical design examples and real-world applications through scientist-in-action videos adds significant educational value, making complex concepts accessible.

electrical engineering

Circuit Gain and Phase Shift

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