Two new high linearity upconverting RF active mixers with integrated RF transformers from Linear Technology deliver linearity and low power consumption. The LT5519 and LT5520 active mixers provide a combination of low distortion, low LO (local oscillator) drive requirement, high port-to-port isolation, low conversion loss and ease of use. The LT5519 operates over the 0.7 GHz to 1.4 GHz range, while the LT5520 covers the 1.3 GHz to 2.3 GHz frequency bands without requiring external matching components. Moreover, their single-ended operation makes the design task easier. These devices respond to the performance demands of the wireless infrastructure market, and have applications in cellular base stations, cable modem and video-on-demand headend equipment and high-performance satellite transceivers.

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An RF output transformer is integrated on-chip to enable single-ended output operation for both the LT5519 and LT5520. The RF port is internally 50-Ohm matched over the devices' full operating frequency range so that no external frequency matching components are typically required.

The mixers have built-in LO amplifiers, eliminating the need for external LO buffers. When used in a radio transmitter, the devices' high LO to RF port-to-port isolation greatly reduces the LO leakage to the RF output, which can cause severe interference to radio equipment in other frequency bands and non-compliance with regulatory emission requirements. As a result, the total solution minimizes costly RF filtering, reduces external components, and lowers the overall cost.

The mixers operate from a single 5 V supply. They typically draw 60 mA of current when operating, while consuming only one microampere when in shutdown mode. The LT5519 and LT5520 are offered in a small 4 mm x 4 mm 16-lead plastic QFN surface-mount package. Pricing starts at $4.15 each in 1000-piece quantities