Next-generation WiMAX systems and LTE mobile data and voice systems are adopting OFDM modulation that supports a large number of subcarriers. The high peak-to-average ratio of these modulated signals causes PAs to be significantly backed off from their maximum transmit powers, thereby making the PA less efficient. To improve PA efficiency, an envelope detector has become increasing popular.

Analog Devices has introduced a highly integrated, high-performance RF detector for use in wireless, instrumentation, defense and other broadband applications. ADI's new ADL5511 TruPwr rms and envelope detector offers a high level of integration and functionality by combining two RF functions into one small chip, thereby simplifying designs and reducing BOM cost.

Operating within the 1 MHz to 4 GHz frequency range, ADI's new ADL5511 TruPwr rms and envelope detector provides a unique approach to improving PAE with a smaller footprint and reduced cost. It is a highly accurate, easy-to-use means of extracting the envelope of a modulated signal. The envelope output is presented as a voltage that is proportional to the envelope of the input signal. The rms output is a linear in V/V output voltage that is independent of the peak-to-average ratio of the input signal. The extracted envelope can be used for power amplifier linearization and efficiency enhancements; the rms output can be used for true power measurement.

The ADL5511 offers best-in-class performance including ±0.25 dB rms detection accuracy versus temperature, ±0.25 dB envelope detection accuracy versus temperature and a ± 1 dB dynamic range of 40 dB. The ADL5511 is specified across the industry's widest temperature range of -40° to +125°C, making it ideal for high-temperature environments found in rem ote radio heads and power amplifiers.

Analog Devices Inc.,
Norwood, MA
(800) 262-5645