Analog Devices

The ADRF6701 provides a quadrature modulator and synthesizer solution within a small 6 mm × 6 mm footprint while requiring minimal external components.The ADRF6701 is designed for RF outputs from 400 MHz to 1250 MHz. The low phase noise VCO and high performance quadrature modulator make the ADRF6701 suitable for next generation communication systems requiring high signal dynamic range and linearity. The integration of the IQ modulator, PLL, and VCO provides for significant board savings and reduces the BOM and design complexity.The integrated fractional-N PLL/synthesizer generates a 2× fLOinput to the IQ modulator. The phase detector together with an external loop filter is used to control the VCO output. The VCO output is applied to a quadrature divider. To reduce spurious components, a sigma-delta (Σ-Δ) modulator controls the programmable PLL divider.The IQ modulator has wideband differential I and Q inputs, which support baseband as well as complex IF architectures. The single-ended modulator output is designed to drive a 50 Ω load impedance and can be disabled.The ADRF6701 is fabricated using an advanced silicon-germanium BiCMOS process. It is available in a 40-lead, exposed-paddle, Pb-free, 6 mm × 6 mm LFCSP package. Performance is specified from −40°C to +85°C. A lead-free evaluation board is available.APPLICATIONSCellular communications systemsGSM/EDGE, CDMA2000, W-CDMA, TD-SCDMA, LTEBroadband wireless access systemsSatellite modems

The ADRF6720-27 is a wideband quadrature modulator with an integrated synthesizer ideally suited for 3G and 4G communication systems. The ADRF6720-27 consists of a high linearity broadband modulator, an integrated fractional-N phase-locked loop (PLL), and four low phase noise multicore voltage controlled oscillators (VCOs).The ADRF6720-27 local oscillator (LO) signal can be generated internally via the on-chip integer-N and fractional-N synthesizers, or externally via a high frequency, low phase noise LO signal. The internal integrated synthesizer enables LO coverage from 356.25 MHz to 2855 MHz using the multicore VCOs. In the case of internal LO generation or external LO input, quadrature signals are generated with a divide by 2 phase splitter. When the ADRF6720-27 is operated with an external 1 × LO input, a polyphase filter generates the quadrature inputs to the mixer.The ADRF6720-27 offers digital programmability for carrier feedthrough optimization, sideband suppression, HD3/IP3 optimization, and high-side or low-side LO injection.The ADRF6720-27 is fabricated using an advanced silicon-germanium BiCMOS process. It is available in a 40-lead, RoHS-compliant, 6 mm × 6 mm LFCSP package with an exposed pad. Performance is specified over the −40°C to +85°C temperature range.Applications2G/3G/4G/LTE broadband communication systemsMicrowave point-to-point radiosSatellite modemsMilitary/aerospaceInstrumentation

The ADRF6750 is a highly integrated quadrature modulator, frequency synthesizer, and programmable attenuator. The device covers an operating frequency range from 950 MHz to 1575 MHz for use in satellite, cellular and broadband communications.The ADRF6750 modulator includes a high modulus fractional-N frequency synthesizer with integrated VCO, providing better than 1 Hz frequency resolution, and a 47 dB digitally controlled output attenuator with 1 dB steps.Control of all the on-chip registers is through a user-selected SPI interface or I2C interface. The device operates from a single power supply ranging from 4.75 V to 5.25 V.