1.5 to 3.8 GHz Active Upconverting Mixer from Linear Technology

The LT5579’s uncompromising performance is well suited for current and next generation wireless transmitters in basestations, including GSM/EDGE, CDMA, CDMA2000, W-CDMA / UMTS and LTE. Additionally, its performance at higher frequencies supports a wide range of wireless broadband access equipment such as WiMAX or WiBro at 2.7GHz and 3.5GHz, cable CMTS and distribution systems, military radios, digital video broadcast systems, 2.4GHz ISM band transmitters, test instrumentations, micro-cells, pico-cells and wireless repeaters.

The LT5579 has integrated RF transformers at both its RF output and LO input to provide differential to single-ended conversion at both ports. This simplifies system design while eliminating or significantly reducing external matching components.

The LT5579’s active, double-balanced design provides several compelling cost-saving benefits. Compared to alternative passive mixers with a typical 8dB conversion loss, the LT5579 offers 2.6dB of gain. This 10dB or more gain advantage eliminates the cost of an extra stage of high power, high linearity RF amplifier. Second, unlike many mixers on the market, the LT5579 can be driven with high signal levels at as much as -5dBm without elevating its outstanding output noise floor above-158dBm/Hz. This feature enables users to drive the transmitter harder while preserving its dynamic range performance. Moreover, most passive mixers have poor LO leakage to the RF output, which is challenging to control, requiring multiple stages of RF filters to achieve adequate suppression. The LT5579’s double-balanced design results in -35dBm LO leakage at the device’s RF output, relaxing and reducing the external filter stages. Overall, the LT5579 offers outstanding performance, compact size and compelling solution cost.

The LT5579 operates from a single 3.3V supply. Typical quiescent supply current is 226mA.The device comes in a 24-lead 5mm x 5mm QFN surface mount package.