功率回退

E类Doherty功放提高了Doherty功放在功率回退时的效率。

They can improve the efficiency of Doherty PA in the power back-off .

为此人们研究了许多功放的线性化方法如功率回退法、前馈法、负反馈法、LINC法和预失真法。

For this purpose , a lot of linearization methods have been investigated including back-off , feed-forward , feedback , LINC and pre-distortion .

传统的功率回退法大大降低了功放的效率。

The traditional back-off method reduces the efficiency of power amplifiers dramatically .

通信技术的发展带动了高线性射频放大器的需求，改善线性的方法通常有功率回退法、反馈法、前馈法和预失真法。

The development of communication technology has created a more demand of high-linearity RF amplifier .

在功放线性化技术方面，文中给出了改进线性度的几种措施，并将功率回退法应用在本课题的驱动级功放中以提高其线性度。

In the linearization techniques of PA , several measures can improve linearity been presented .

传统的功率回退应用方法存在器件及效率方面的限制。

However , traditional power back off method owns poor efficiency and is limited by electronic devices .

采用了功率回退法和前馈法，使本功率放大器的三阶交调优于51dBc。

Using power back and feedforward methods , the IM_3 of this power amplifier is better than 51 dBc .

为保证通信质量，如果采用简单的功率回退，使功率放大器一直工作在线性区间，那么功放的效率会很低。

The efficiency is low if we adopt simple power back-off to make power amplifier work in linear aera .

因此，在功率回退条件下，提高功率放大器效率，能够节约能源，降低功耗。

Therefore , improving efficiency of power amplifier at power back-off condition can save energy and reduce power consumption .

为了提高线性度，基站和移动终端放大器纷纷降额使用，采用功率回退的方式来提高线性度。

In order to improve linearity , the power amplifiers are degraded and used in the power back off region .

第三部分主要介绍一些线性化方法，比如前馈法、功率回退法等，并对本文采用的数字基带预失真方法进行了详细的介绍。

The third part introduces a number of linear methods , such as feed-forward method , power back law , and mainly about digital baseband predistortion .

目前应用比较广泛的线性化技术有正向前馈、模拟预失真、数字预失真、负反馈以及功率回退等方法。

The mainly linear technologies widely used in nowadays conclude as fellows : feedforward , analog predistortion , digital predistortion , negative feedback , power back and so on .

在卫星通信中，由于卫星信道是典型的非线性信道，经常使用等能量符号的调制方式以便非线性放大器能以最小的功率回退工作在线性区内。

In satellite communications , the use of equal energy symbols is preferred so that the non-linear amplifier can operate in its approximately linear range with minimal backoff , because the satellite channel is a typical nonlinear channel .

由于该功放要求工作频带宽，线性度较高，且能脉冲或连续波工作，因此在理论设计上笔者采用了宽带匹配、功率回退、漏极电源调制等技术。

Because this PA has the features of broad operating band and high linearity , and it can work in CW or pulse state , wide-band matching , power back-off , drain power modulating , and other technologies are used in the design .

为了满足线性度的要求，则往往采用一定的功率回退的方法来达到线性度的提升，然而随着功率的回退，放大器效率如功率附加效率也会大大的降低。

In order to meet the linearity requirements , it often uses a certain degree of power back-off approach to achieve the increase of the linearity , however , with the power back-off , amplifier efficiency , such as the power-added efficiency will be greatly reduced .

传统的功率放大器设计是采用功率回退法来获得高线性，然而这是以牺牲效率为代价的。

The design of traditional power amplifier utilizes the method of power back-off to obtain a high linearity at the expense of efficiency .

为了保证峰值功率的线性度，放大器功率必须回退的更多，效率也就更低。功放的效率低下会导致高能耗和通信设备散热问题，最终影响通信设备的性能。

In order to ensure the linearity of peak power , power must be more back-off and also less efficient which leads to more waste of energy and heat dissipation of communication equipment and ultimately affects the performance of communication equipment .

所设计的射频2W线性功率放大器是基于负载线匹配原理，采用功率回退法技术。

The 2W linear RF Power Amplifier in this paper is designed in Feedback method , based on Loadline Theory .

目前线性功率放大器的设计主要采用前馈、预失真和功率回退等线性化技术。

Feedforward , Predistortion and Feedback linearization techniques are mostly used in Linearity Power Amplifier Design .

先是对功率放大器的线性度进行了介绍，继而描述了AM-AM与AM-PM特性曲线，最后就功率回退方法对60GHz通信下OFDM系统产生的影响进行了分析与仿真。

Firstly , we introduce the linearity of the power amplifier . Secondly we describe the AM-AM , AM-PM characteristics curve . At last , we analysis and stimulate the effect which power back-off brings about in the communication system with OFDM modulation .

所以，解决功率放大器的非线性失真就成为了当前一个非常重要的课题。目前功率放大器的线性化技术主要包括功率回退法、负反馈法、LINC法、前馈法以及预失真法。

Solving nonlinear distortion of the power amplifier has become a very important issue now . Recently , there are amplifier linearization such as power back-off , feedback , LINC , feed-forward and predistortion .