Date: 15/05/2012

Wideband I/Q demodulator from Linear with IIP2 optimization & DC offset cancellation

Linear Technology has announced an ultra wide bandwidth direct conversion I/Q demodulator, the LTC5584. This device has linearity of 31dBm IIP3 and 70dBm IIP2. The demodulator offers demodulation bandwidth of over 530MHz, supporting the latest generation of LTE multimode, LTE advanced receivers and digital predistortion (DPD) receivers.

The LTC5584 have two built-in calibration features. One is advanced circuitry that enables the system designer to optimize the receiver's IIP2 performance, increasing from a nominal 70dBm to an unprecedented 80dBm or higher. The other is on-chip circuitry to null out the DC offset voltages at the I-Q outputs. The device exacts P1dB of 12.6dBm, along with its 13.6dB noise figure under a 0dBm in-band blocker, ensuring better receiver performance.

This device is suitable for multimode LTE and CDMA DPD receivers as well as other wideband receiver applications. They are also suitable for military receivers, broadband communications, point-to-point microwave data links, image-reject receivers and long range RFID readers.

Features of LTC5584:
1. Operating frequency: 30MHz - 1.4GHz (450MHz/700MHz LTE frequency bands covered)
2. Input IP3 (450MHz): 31dBm
3. Input IP2 (unadjusted): 70dBm
4. Input IP2 (adjusted): >80dBm
5. Conversion gain (NF): 5.4dB
6. Noise figure (NF): 9.9dB
7. I/Q amplitude mismatch: 0.02dB
8. I/Q phase mismatch: 0.25°
9. Operating temperature: -40°C to 105°C
10. Supply: 5V (supply current of 200mA)
11. Package: 24 lead 4 x 4 mm QFN

The LTC5584 is priced at $5.65 each in 1,000-piece quantities.