300mhz to 9ghz high linearity I/Q demodulator supports 1GHz bandwidth and achieves up to 60dB image rejection

A wideband, high linearity true zero-IF (ZIF) demodulator from Analog Devices has been launched, which it says has 1GHz instantaneous I and Q 1dB bandwidth.

According to Analog, the LTC5594 demodulator is capable of 37dB image rejection typical. Using an on-chip serial port allows correction of the I and Q phase and amplitude imbalance, Analog adds, meaning it can tuned to achieve an image rejection of better than 60dB. This is said to ease calibration while improving receiver performance and reducing FPGA resources needed to null the residual image.

The device, offered in a 32-lead, 5mm x 5mm plastic QFN package, also has integrated baseband amplifiers with adjustable gain. Analog claims this provides a maximum power conversion gain of 9.2dB at 5.8GHz, while delivering 37dBm output IP3 performance.

The RF input has an integrated wideband balun transformer, which is said to allow single-ended operation with 50Ω matching from 500MHz to 9GHz.

By changing one external matching component value, Analog explains the same input can be matched at lower frequencies from 300MHz to 500MHz and its high level integration results in minimum external components and small solution size.

Bethan Grylls