آر اف (فرکانس رادیویی) و بی‌سیم دمودولاتور آر اف

Product Attributes

Introduction

The ADL5387 is a broadband quadrature I/Q demodulator that covers an RF/IF input frequency range from 30 MHz to 2 GHz. With a noise figure (NF) of 13.2 dB, 1-dB compression point (IP1dB) of 12.7 dBm, and third-order intercept point (IIP3) of 32 dBm at 450 MHz, the ADL5387 demodulator offers outstanding dynamic range suitable for the demanding infrastructure direct-conversion requirements. The differential RF/IF inputs provide a well-behaved broadband input impedance of 50 Ω and are best driven from a 1:1 balun for optimum performance.

Ultrabroadband operation is achieved with a divide-by-2 method for local oscillator (LO) quadrature generation. Over a wide range of LO levels, excellent demodulation accuracy is achieved with amplitude and phase balances of approximately 0.05 dB and 0.4°, respectively. The demodulated in-phase (I) and quadrature (Q) differential outputs are fully buffered and provide a voltage conversion gain of greater than 4 dB. The buffered baseband outputs are capable of driving a 2 Vₚ₋ₚ differential signal into 200 Ω.

The fully balanced design minimizes effects from second-order distortion. The leakage from the LO port to the RF port is less than -70 dBc. Differential dc-offsets at the I and Q outputs are less than 10 mV. Both of these factors contribute to the excellent second-order intercept point (IIP2) specifications of greater than 60 dBm.

The ADL5387 operates off a single 4.75 V to 5.25 V supply. The supply current is adjustable with an external resistor from the BIAS pin to ground.

Features

• Operating RF frequency 30 MHz to 2 GHz
• LO input at 2 times t̂₁₀ 60 MHz to 4 GHz
• Input IP3: 31 dBm at 900 MHz
• Input IP2: 62 dBm at 900 MHz
• Input P1dB: 13 dBm at 900 MHz
• Noise figure (NF) 12.0 dB at 140 MHz 14.7 dB at 900 MHz
• Voltage conversion gain > 4 dB
• Quadrature demodulation accuracy Phase accuracy ~0.4° Amplitude balance ~0.05 dB
• Demodulation bandwidth ~240 MHz
• Baseband I/Q drive 2 Vₚ₋ₚ into 200 Ω
• Single 5 V supply

Applications

• QAM/QPSK RF/IF demodulators
• W-CDMA/CDMA/CDMA2000/GSM
• Microwave point-to-(multi)point radios
• Broadband wireless and WiMAX
• Broadband CATVs