Catalog
30 MHzTO 2 GHzQuadrature Demodulator
Key Features
• Operating RF frequency30 MHz to 2 GHz
• Voltage conversion gain > 4 dB
• Input IP3: 31 dBm @ 900 MHz
• Input IP2: 62 dBm @ 900 MHz
• Input P1dB: 13 dBm @ 900 MHz
• Noise figure (NF)12.0 dB @ 140 MHz14.7 dB @ 900 MHz
• LO input at 2 × fLO
• Quadrature demodulation accuracyPhase 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
Description
AI
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 NF = 13.2 dB, IP1dB = 12.7 dBm, and IIP3 = 32 dBm @ 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 ~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 >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 <−70 dBc. Differential dc-offsets at the I and Q outputs are <10 mV. Both of these factors contribute to the excellent IIP2 specifications > 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.The ADL5387 is fabricated using the Analog Devices, Inc. advanced silicon-germanium bipolar process and is available in a 24-lead exposed paddle LFCSP.APPLICATIONSQAM/QPSK RF/IF demodulatorsW-CDMA/CDMA/CDMA2000/GSMMicrowave point-to-(multi)point radiosBroadband wireless and WiMAXBroadband CATVs
