CML Unveils RF Quadrature Modulator

13th November 2008

ES Admin

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CML Microcircuits unveiled an I/Q modulator at the Electronica exhibition in Munich, Germany, adding to its family of RF integrated circuits. The new CMX993 is a highly integrated, general purpose, RF quadrature modulator, offering 100MHz to 1GHz operation and excellent wide-band noise performance. Additional features include gain control and uncommitted differential amplifiers.

Targeted to meet the challenging requirements of wireless data (digital TV, CATV modulators, ISM transmitters, Wireless LAN, WLL) and two-way radio systems (APCO P25), the product’s I/Q architecture supports a wide range of modulation types. Various integrated, selectable functions are offered, to maintain performance across multiple modulations and bandwidths.

The quadrature modulator provides translation from baseband I/Q signals to a modulated RF signal. The wideband inputs can be driven single-ended or differentially for optimum performance. The device offers two integrated and matched double-balanced mixers, driven from a buffered quadrature split local oscillator. The ‘LO’ frequency is divided by either 2 or 4, with the mixers forming an I/Q vector modulator with programmable gain stages, offering 30dB of gain control in 2.5dB steps.

A digital control interface, C-BUS (SPI compatible interface), allows gain control as well as the power management of individual internal blocks for optimum system performance. The C-BUS interface operates from its own power supply, enabling the CMX993 to be interfaced to baseband devices of differing voltages.