Dual wideband mixer with programmable gain amplifiers enables 5G wireless access
Linear Technology has introduced the LTC5566, a new wideband, high dynamic range dual channel mixer with integrated programmable variable gain IF amplifiers. This dual mixer has a very wide, 300MHz to 6GHz input frequency range, specifically optimized and with extensive characterization at the emerging 3.6GHz and 4.5GHz 5G bands, as well as the established 4G bands. Moreover, the device supports bandwidths up to 400MHz to meet the needs of the growing sub-6GHz 5G wireless access equipment. This dual mixer has outstanding dynamic range, with Input P1dB of +11.5dBm and Input IP3 of +25.5dBm at 3.6GHz. At higher frequencies, up to 5.8GHz, its IIP3 sustains more than +24dBm. The device’s integrated IF amplifier boosts the overall power conversion gain to a maximum of 12dB. The gain of each channel is independently programmed in precise 0.5dB steps via the on-chip SPI bus. So, with each channel driving an A/D converter, the fine gain control provides a simple means to balance the gain of the two channels and calibrate to the optimum level with minimal external components.
The device is ideal for use in 5G wireless multichannel RRH (remote radio head) wireless access equipment that requires better performance and wider bandwidths at higher frequencies. Moreover, the device’s high level of integration enables high channel counts to be packed into a small enclosure. Other suitable applications include 4G LTE-Advanced, diversity receivers, distributed antenna systems and software-defined radio.
The device operates from a single 3.3V supply. With both channels on, the device draws a nominal supply current of 384mA. Each mixer can be turned on or off independently with separate control lines. Additionally, a low power mode is available, ensuring operation at a reduced supply current of 294mA, although with a slight decrease in IP3 performance. The product is rated for –40C to 105C case temperature operation and is offered in a 5mm x 5mm 32-lead plastic QFN package.