High linearity mixer offers 3-20GHz bandwidth

Article By : Linear Technology

Linear Technology's LTC5553 delivers a linearity of 23.9 dBm IIP3 at 14GHz and 21.5 dBm at 17GHz while integrating an LO buffer requiring only 0dBm input drive.

Linear Technology Corp. claims its double balance mixer provides top-notch matched bandwidth capability from 3GHz to 20GHz and can be used either as an up- or downconverter.

The LTC5553 delivers a linearity of 23.9dBm IIP3 at 14GHz and 21.5dBm at 17GHz, the company said. The device integrates an LO buffer requiring only 0dBm input drive, eliminating an external high power LO amplifier circuit. The LTC5553 also integrates wideband balun transformers on chip. All ports operate single-ended, 50 Ω matched over their respective specified frequency range. In addition, the mixer has excellent port-to-port isolation, offering -32dBm LO to RF leakage at 17GHz, thus easing external filtering requirements. All of these features result in minimum external components, simplified design, and a very small solution size, Linear said.

The device's wide bandwidth and performance is ideal for a wide range of applications including 5G microwave backhaul, broadband wireless services, satellite broadband radios, radar systems, active antenna arrays, X and Ku band transceivers, test equipment, spectrum analysis, and satellite communications.

The LTC5553 is offered in a small 12-lead, 3 mm x 2 mm plastic QFN package. It is rated for operation from -40°C to 105°C case temperature to support extended environmental operating temperature. The mixer is powered from a single 3.3V supply, drawing a quiescent supply current of 132mA. Additionally, the device can be shut down via an enable pin. 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 time-division duplex (TDD) or burst mode type transmitters and receivers.

The LTC5553 is priced starting at $22 each in 1,000-piece quantities.