آر اف (فرکانس رادیویی) و بی‌سیم مدولاتور آر اف

Product Attributes

Introduction

The AD8349 is a silicon, monolithic, RF quadrature modulator that is designed for use from 700 MHz to 2700 MHz. Its excellent phase accuracy and amplitude balance enable high performance direct RF modulation for communication systems.

The differential LO input signal is buffered, and then split into an in-phase (I) signal and a quadrature-phase (Q) signal using a polyphase phase splitter. These two LO signals are further buffered and then mixed with the corresponding I channel and Q channel baseband signals in two Gilbert cell mixers. The mixers’ outputs are then summed together in the output amplifier. The output amplifier is designed to drive 50 Ω loads.

The RF output can be switched on and off within 50 ns by applying a control pulse to the ENOP pin.

The AD8349 can be used as a direct-to-RF modulator in digital communication systems such as GSM, CDMA, and WCDMA base stations, and QPSK or QAM broadband wireless access transmitters. Its high dynamic range and high modulation accuracy also make it a perfect IF modulator in local multipoint distribution systems (LMDS) using complex modulation formats.

The AD8349 is fabricated using Analog Devices’ advanced complementary silicon bipolar process, and is available in a 16 - lead, exposed-paddle TSSOP package. Its performance is specified over a -40℃ to +85℃ temperature range.

Features

• Output frequency range: 700 MHz to 2700 MHz
• Modulation bandwidth: dc to 160 MHz (large signal BW)
• 1 dB output compression: 5.6 dBm @ 2140 MHz
• Output disable function: output below –50 dBm in <50 ns
• Noise floor: –156 dBm/Hz
• Phase quadrature error: 0.3 degrees @ 2140 MHz
• Amplitude balance: 0.1 dB
• Single supply: 4.75 V to 5.5 V
• Pin compatible with AD8345/AD8346s
• 16-lead, exposed-paddle TSSOP package

Applications

• Cellular/PCS communication systems infrastructure
• WCDMA/CDMA2000/PCS/GSM/EDGE
• Wireless LAN/wireless local loop
• LMDS/broadband wireless access systems