superheterodyne receiver

简明释义

超外差式接收机

英英释义

例句

1.In a superheterodyne receiver 超外差接收机, the incoming signal is mixed with a local oscillator signal.

在超外差接收机中，输入信号与本地振荡器信号混合。

2.One of the advantages of a superheterodyne receiver 超外差接收机 is its ability to select a narrow bandwidth.

一个超外差接收机的优点是能够选择窄带宽。

3.The superheterodyne receiver 超外差接收机 is widely used in modern radio systems.

现代无线电系统广泛使用超外差接收机。

4.Many television and radio stations utilize a superheterodyne receiver 超外差接收机 for better signal clarity.

许多电视和广播电台使用超外差接收机以获得更好的信号清晰度。

5.The design of a superheterodyne receiver 超外差接收机 includes multiple stages of amplification.

超外差接收机的设计包括多个放大阶段。

作文

In the world of electronics and communication, the term superheterodyne receiver refers to a type of radio receiver that is widely used for its ability to receive and process signals effectively. The concept was first developed in the early 20th century and has since become the standard for most radio frequency (RF) communication systems. A superheterodyne receiver operates by converting the received signal to a lower intermediate frequency (IF) which makes it easier to filter and amplify. This conversion process involves mixing the incoming signal with a locally generated frequency, known as the local oscillator, to produce the IF signal.The architecture of a superheterodyne receiver typically includes several key components: an antenna, a mixer, an oscillator, and an amplifier. The antenna captures the electromagnetic waves that carry the information. Once the signal is captured, it is fed into the mixer where it is combined with the output from the local oscillator. The result of this mixing process is the generation of two new frequencies: one at the sum of the two original frequencies and another at their difference. The difference frequency is what we refer to as the intermediate frequency (IF).One of the main advantages of a superheterodyne receiver is its ability to easily select and amplify a specific frequency while rejecting others. By using bandpass filters at the IF stage, the receiver can isolate the desired signal from unwanted noise and interference. This capability is especially important in crowded radio frequency environments where multiple signals may be present simultaneously.Moreover, the superheterodyne receiver provides excellent performance in terms of sensitivity and selectivity. Sensitivity refers to the receiver's ability to detect weak signals, while selectivity is its ability to distinguish between closely spaced frequencies. As a result, this type of receiver is commonly found in various applications including AM and FM radio, television, and even in modern wireless communication systems such as cellular networks and Wi-Fi.Despite its many benefits, the superheterodyne receiver does have some drawbacks. One significant challenge is the potential for image frequency interference. This occurs when an undesired signal at a frequency equal to the sum of the local oscillator frequency and the IF is also mixed in the receiver, potentially leading to confusion and distortion of the desired signal. To mitigate this issue, careful design considerations must be taken into account when selecting the local oscillator frequency and designing the front-end filtering.In conclusion, the superheterodyne receiver is a fundamental component in modern communication systems, providing a reliable means of receiving and processing radio signals. Its ability to convert high-frequency signals to a more manageable intermediate frequency allows for enhanced filtering and amplification, making it a preferred choice in various applications. Understanding the workings and importance of the superheterodyne receiver is crucial for anyone interested in the field of electronics and communications. As technology continues to evolve, the principles behind the superheterodyne receiver will likely remain relevant, adapting to meet the demands of future communication systems.

在电子和通信的世界中，术语超外差接收机指的是一种广泛用于有效接收和处理信号的无线电接收机。这一概念最早是在20世纪初开发的，并且自那时以来，它已成为大多数射频（RF）通信系统的标准。超外差接收机通过将接收到的信号转换为较低的中频（IF）来工作，这使得过滤和放大变得更加容易。这个转换过程涉及将输入信号与一个称为本振的局部生成频率混合，以产生IF信号。超外差接收机的架构通常包括几个关键组件：天线、混频器、振荡器和放大器。天线捕获携带信息的电磁波。一旦信号被捕获，它就会被送入混频器，在那里它与本振的输出结合。这个混合过程的结果是生成两个新频率：一个是两个原始频率之和的频率，另一个是它们的差频。差频就是我们所说的中频（IF）。超外差接收机的主要优点之一是它能够轻松选择和放大特定频率，同时拒绝其他频率。通过在IF阶段使用带通滤波器，接收机可以将所需信号从不必要的噪声和干扰中隔离开来。这种能力在拥挤的射频环境中尤其重要，因为多个信号可能同时存在。此外，超外差接收机在灵敏度和选择性方面提供了出色的性能。灵敏度指的是接收机检测微弱信号的能力，而选择性则是其区分相邻频率的能力。因此，这种类型的接收机通常在各种应用中找到，包括AM和FM广播、电视，甚至现代无线通信系统如蜂窝网络和Wi-Fi。尽管有许多优点，超外差接收机确实存在一些缺点。一个显著的挑战是图像频率干扰。这发生在当一个不需要的信号在与本振频率和IF之和相等的频率下也被混入接收机时，可能会导致所需信号的混淆和失真。为了减轻这个问题，在选择本振频率和设计前端过滤时，必须考虑仔细的设计因素。总之，超外差接收机是现代通信系统中的一个基本组成部分，提供了一种可靠的手段来接收和处理无线电信号。它将高频信号转换为更易于管理的中频的能力允许增强的过滤和放大，使其在各种应用中成为首选。理解超外差接收机的工作原理和重要性对于任何对电子和通信领域感兴趣的人来说都是至关重要的。随着技术的不断发展，超外差接收机背后的原理很可能仍然是相关的，适应未来通信系统的需求。