RF switch enables dual-band architecture for DOCSIS 3.1 Devices

Until now, no switch has met the linearity requirements necessary to support a dual-band architecture. This new device uses a dual-band architecture, and gives multi-service operators (MSOs) the flexibility to offer their customers new and expanded services while CPEs can comply with the new DOCSIS 3.1 cable industry standard.

MSOs also benefit from the switch supporting both DOCSIS 3.0 and 3.1, allowing for a simple and cost-effective transition to DOCSIS 3.1.

When upgrading to a different high-speed service plan, the customer currently is faced with the inconvenience of physically changing the CPE device to get the hardware necessary to support the higher upstream and downstream band requirements. The introduction of the PE42722 high-linearity switch marks the first time that dual upstream/downstream bands can reside in the same CPE device. Once CPE devices are equipped with the switch, the exchanging of hardware will no longer be necessary.

An additional benefit of the device is its compliance with the DOCSIS 3.0 and 3.1 cable standards. The cable industry faces the challenge of supporting the customer’s increasing demand for more high-speed home data. In order to meet this rise in data consumption, the industry announced the DOCSIS 3.1 standard in Oct. 2013.

These new DOCSIS 3.1 requirements put enormous pressure on the entire cable industry eco system, from CPE devices to the infrastructure. To ease the infrastructure transition to the higher speeds and eliminate the need to replace the CPE, these devices must incorporate the flexibility to accommodate multiple upstream/downstream frequency band definitions.

To create a dual-band architecture, a switch must be placed directly at the cable modem (CM) connector before the filters and needs to comply with the stringent DOCSIS 3.1 CM spurious emissions requirements of -50 dBmV. Such a low spurious level requires the switch harmonic performance to be better than -115dBc. Peregrine Semiconductor says that the PE42722 is the only RF switch available today that can achieve these high harmonic requirements.

Covering a frequency range of 5-1,794 MHz, the device readily supports an average input power greater than 65 dBmV. The switch’s low insertion loss (0.3 dB at 1218 MHz) preserves noise figure and receiver sensitivity and achieves superior signal quality, along with providing high isolation of 40 dB at 612 MHz. It also features a low current consumption of 130 µA, standard +1.8V and +3.3V logic support, a wide voltage supply range from 2.3 to 5.5V, and 1.5 kV ESD protection on all pins.