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GENERAL DESCRIPTION The WS2017 is a third generation Tunable Impedance Matching Circuit. It is designed to be inserted in the RF signal chain between the antenna and the front-end module (FEM) of a mobile phone and provides superior transmit and receive chain optimization over the full 824 MHz – 2170 MHz mobile frequency range. WiSpry’s innovative tunable capacitor technology enables a completely new type of RF matching component that combines excellent RF performance from a high-Q parallel plate capacitor and fixed inductance network with versatile digital control of the capacitance values. The entire TX/RX signal chains can now be optimized resulting in superior TRP and TIS numbers with low physical volume antennas. The WS2017 can be quickly re-configured to compensate for antenna source impedance changes due to frequency band and different external load to cover hand, head and body effects. Using a modem serial control interface, the WS2017’s high-Q circuits transform mismatched and varying antenna impedances from being poorly matched to well-matched. The result is improved RF performance and greater energy efficiency. The antenna impedance match is digitally controlled by the programmable capacitive elements implemented in WiSpry’s CMOS-RF MEMS structure. The WS2017 features an integrated high voltage charge pump for electrostatic actuation and bi-directional SPI serial control bus. The SPI mode is compatible with most RF transceiver implementations. The ultra low power WS2017 can be driven by an existing single supply rail such as an LDO regulator output or directly from the battery supply. The charge pump, serial bus and driver circuits are all fully integrated on the same CMOS die as the MEMS capacitor elements, making the WS2017 a true single chip solution for antenna impedance matching. The WS2017 is intended primarily for openloop impedance control. Optional closed loop mode is achieved by adding external control and detection circuitry. By migrating from a compromised fixed match that covers all frequencies from 824 MHz to 2170 MHz and possible external loadings, to a realtime optimized solution with WS2017, the overall efficiency of the RF chain and antenna can be improved. FEATURES • • • • • • • • • • • • True single chip CMOS antenna tuner Improved TRP and TIS from 824 – 2170 MHz Corrects for VSWR up to 20:1 Covers GSM850, EGSM, DCS, PCS and WCDMA I, II, III, IV*, V, VI, VIII, IX, X*, XI. ** Precise digital control with 0.125 pF step size Ultra low harmonics and inter-modulation Fully integrated charge pump circuit Software control of “body effects” tuning Bidirectional, 3 and 4-Wire SPI dual mode serial bus Ultra low power sleep mode Optimized for effective PCB layout ADS die and package models available *Bands IV and X fall within the WS2018 frequency range but have extremely large duplex distance and may require a special matching methodology **Can be used for 700 MHz/2600 MHz LTE frequency bands, contact WiSpry Application support for guidance System Block Diagram APPLICATION With a WS2017 in the signal chain, different external and internal load variations such as head phantom, hand phantom, open/closed flip and slide effects as well as variations due to channel and band of operation can be reduced or eliminated providing an optimal antenna match regardless of operating band and user phone position. Handset Architecture with WS2017