基于BLF888設計的500W RF廣播發射方案

BLF888是500W LDMOS RF功率晶體管，用于廣播發射和工業應用。在UHF頻帶470 MHz 到860 MHz可提供平均功率110W，峰值包絡功率500W，功率增益19dB，漏極效率46%，VDS 電壓50 V，漏極靜態電流1.3A。本文主要介紹了BLF888主要特性和優勢，AB類共源寬帶放大器電路和元件列表以及PCB布局圖和元件布局圖。

A 500 W LDMOS RF power transistor for broadcast transmitter applications and industrial applications. The transistor is optimized for digital applications and can deliver 110 W average DVB-T broadband over the full UHF band from 470 MHz to 860 MHz. The excellent ruggedness of this device makes it ideal for digital transmitter applications.

BLF888主要特性和優勢：

2-Tone performance at 860 MHz, a drain-source voltage VDS of 50 V and a quiescent drain current IDq = 1.3 A:

Peak envelope power load power = 500 W

Power gain = 19 dB

Drain efficiency = 46 %

Third order intermodulation distortion = 32 dBc

DVB performance at 858 MHz, a drain-source voltage VDS of 50 V and a quiescent drain current IDq = 1.3 A:

Average output power = 110 W

Power gain = 19 dB

Drain efficiency = 31 %

Shoulder distance = 31 dBc (4.3 MHz from center frequency)

Integrated ESD protection

Advanced flange material for optimum thermal behavior and reliability

Excellent ruggedness

High power gain

High efficiency

Designed for broadband operation (470 MHz to 860 MHz)

Excellent reliability

Internal input matching for high gain and optimum broadband operation

Easy power control

Compliant to Directive 2002/95/EC, regarding Restriction of Hazardous Substances (RoHS)

BLF888應用：

Communication transmitter applications in the UHF band

Industrial applications in the UHF band


圖1。BLF888 AB類共源寬帶放大器電路

AB類共源寬帶放大器元件列表：




圖2。AB類共源寬帶放大器PCB布局圖

圖3。AB類共源寬帶放大器元件布局圖