2.7GHz, 60dB mean-squared power detector responds in 500ns
( 01 Mar 2008 )
A new wide dynamic range mean-squared RF detector from Linear Technology sets a new level of accuracy and speed performance. The LT5570 provides accurate RMS (Root-Mean-Squared) power measurement of a 40MHz to 2.7GHz AC signal over 60dB dynamic range, even with a modulation crest-factor of up to 12dB. It offers best-in-class measurement accuracy of ±0.5dB over its full dynamic range and over a temperature range of -40° to +85°C. Moreover, the device allows exceptionally fast response with a full-scale rise time of 500ns.
The LT5570 provides a DC output proportional to the RMS value of the input signal power. Even if the input waveform has high crest-factor content, such as a 4-carrier W-CDMA modulated waveform, its RMS conformance accuracy is typically within 0.2dB, compared to that of a CW (continuous waveform) power. The device offers 61dB dynamic range at 880MHz, and 51dB at 2.14GHz. Its linear DC output is proportional to the input power in dBm with a scaling factor of 36.5mV/dB, typical. Minimum sensitivity is -53dBm at 880MHz, and -43dBm at 2.14GHz. The device offers exceptional linearity, deviating less than ±0.5dB from the ideal log-linear straight line, and over the device’s operating temperature extremes.
