Passive Mixers Provide Gain From 700 To 2800 MHz

A pair of passive mixers incorporate a unique broadband local-oscillator (LO) amplifier to achieve broadband operation from 700 to 2800 MHz. The single-channel ADL5811 and dual-channel ADL5812 passive mixers integrate a broadband square-wave limiting LO amplifier with bandwidth of 450 to 2760 MHz, allowing the LO to be used above or below RF input signals. Using a high-linearity intermediate-frequency (IF) buffer amplifier, the result is better than 7 dB power conversion gain and input third-order intercept point of +24 dBm. These broadband passive mixers also feature 11 dB of single-sideband (SSB) noise figure. In addition, the mixers boast a programmable RF-balun structure that ensures an input 1-dB compression point of +12 dBm over the full RF bandwidth. The LO port of the ADL5811 and ADL5812 can be switched between single-ended and balanced operation using a three-wire serial port interface (SPI). Performance can be further optimized by digitally adjusting the DC bias voltage to the passive-mixer gates. To minimize power dissipation, each channel of the dual-channel ADL5812 can be enabled or disabled independent of the other. Programmability is gained through a Universal Serial Bus (USB)-based programming software, which provides a slider-bar tool. The engineer can select the frequency that is appropriate for the intended usage of the part, essentially talking to the mixer through a USB port. The passive mixers are designed for wideband wireless-infrastructure applications and software-defined-radio (SDR) applications including multiband/multi-standard cellular base-station receivers, wideband-radio-link downconverters, multi-mode cellular repeaters, and picocell applications. They are fabricated with a silicon BiCMOS process and supplied in 32-lead LFCSP packages measuring 5 x 5 mm. P&A: $8.03 for the ADL5811 and $10.98 for the ADL5812 in 1000Q.

Analog Devices, Inc.
3 Technology Way
Norwood, MA 02062
www.analog.com

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