Wideband mixer delivers IF bandwidth from DC to 6GHz
The LTC5548, a double balanced mixer that operates either as an up- or downconverter with a wide frequency range from 2 to 14GHz, has been introduced by Linear Technology. The LTC5548 features integrated balun transformers at the RF and LO ports, providing 50Ω match from 2 to 13.6GHz and from 1 to 12GHz at each port, respectively, while enabling single-ended operation.
The LTC5548's IF port is capable of DC to 6GHz, supporting wideband transmitters and receivers at the baseband. The mixer provides high linearity: 24.4dBm IIP3 at 5.8GHz; and 21.4dBm at 9GHz.
The LTC5548 simplifies microwave transmitter and receiver designs with its integrated LO buffer, requiring only a 0dBm drive, effectively eliminating an external high power LO amplifier circuit. The LTC5548 also has a selectable on-chip LO frequency doubler, enabling the device to use lower cost, commonly available low frequency synthesisers. The LTC5548 mixer features exceptional port-to-port isolation, minimising undesirable LO leakage, easing external filtering requirements.
The LTC5548’s performance is suited for a wide range of microwave applications, including broadband microwave backhaul, the emerging 5.8GHz unlicensed band and 14GHz LTE-A broadband wireless services, satellite broadband transceivers, radar systems, X-band and Ku band transceivers, spectrum analysers, RF test equipment and satellite modems.
The LTC5548 has exceptionally robust ESD handling capability of 2,000V ESD HBM on all pins. The mixer is powered from a single 3.3V supply, drawing a nominal supply current of 120mA. Additionally, the LTC5548 has an enable pin to shut down the IC. When deactivated, the device draws only 100µA maximum standby current. The enable pin can be driven directly to turn the device on and off rapidly in less than 0.2µs, supporting TDD or burst mode type radios. The device is rated for operation from -40 to +105°C case temperature.
The device comes in a tiny 12-lead 3x2mm plastic QFN package, providing a compact solution footprint, requiring minimal external components. The LTC5548 is priced from $9.50 each in 1,000 unit quantities. Samples and production quantities are available immediately.