1550 MHz to 2650 MHz Quadrature Modulator with 2100 MHz to 2600 MHz Fractional-N PLL & Integrated VCO

The ADRF6703 provides a quadrature modulator and synthesizer solution within a small 6 mm × 6 mm footprint while requiring minimal external components.

The ADRF6703 is designed for RF outputs from 1550 MHz to 2650 MHz. The low phase noise VCO and high performance quadrature modulator make the ADRF6703 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× fLO input 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 ADRF6703 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.

APPLICATIONS

* Cellular communications systems

GSM/EDGE, CDMA2000, W-CDMA, TD-SCDMA, LTE

* Broadband wireless access systems

* Satellite modems

* IQ modulator with integrated fractional-N PLL

* RF output frequency range: 1550 MHz to 2650 MHz

* Internal LO frequency range: 2100 MHz to 2600 MHz

* Output P1dB: 14.2 dBm @ 2140 MHz

* Output IP3: 33.2 dBm @ 2140 MHz