RF amplifier delivers high power with 256 QAM modulation

August 25, 2014 // By Graham Prophet
SST12CP21 is a 2.4 GHz 256-QAM RF high-power amplifier that offers low EVM and current consumption for IEEE 802.11n systems. It delivers high linear output power of up to 23 dBm at 1.75% dynamic EVM, with MCS9 HT40 MHz bandwidth modulation at 5V and 320 mA current consumption.

The amplifier provides 25 dBm of linear power, at 3% EVM with 350 mA current consumption for 802.11g/n applications. This performance extends the range of 802.11b/g/n WLAN and MIMO systems, while consuming extremely low current at the maximum 256-QAM data rate. The SST12CP21 is also spectrum mask compliant up to 28 dBm for 802.11b/g communication. Board space is reduced by the 3 x 3 x 0.55 mm, 16-pin QFN package that matches a popular pin-out.

Achieving the maximum data rate and longest range while minimizing current consumption is essential to Wi-Fi MIMO access-point, router and set-top-box system designers, to enable multichannel and higher data rate WLAN systems. This amplifier also features 50Ω on-chip input match and simple output match, which is easy to use and reduces board size. The integrated linear power detector provides accurate output power control over temperature and 2-to-1 output mismatch.

“Microchip's RF power amplifiers have a strong position in the WLAN market, due to their reliability combined with high-power efficiencies that can only be achieved using InGaP/GaAs HBT,” said Daniel Chow, vice president of Microchip’s RF Division. “The SST12CP21 provides the same reliable operation over temperature, at an even lower EVM. In conjunction with its higher-efficiency operation of only 320 mA at 23 dBm at 1.75% EVM, and 350 mA at 25 dBm at 3% EVM, this new power amplifier extends the range of both 802.11n and ultra-high data rate, 256-QAM MIMO systems.”