Power detector works across 9kHz to 7GHz in both directions

ADL5920 detector represents a change to conventional approaches by integrating a directional bridge-based coupler which integrates the coupling or sensing function with the detection function and provides an output that can drive an ADC directly.

Forward and reverse power in the bridge is measured using two high range RMS detectors. The ratio of the forward and reverse power levels is also measured and provided as a differential output voltage with an adjustable common mode level. Bridge and detector circuitry is internally DC coupled to allow for frequency measurements. By applying an optional -2.5V negative supply, ground referenced dc-coupled signals can be applied.

“For wideband operation or for frequency variants, ADL5920 detector eliminates the need to choose a different directional coupler for each frequency,” said the firm.

Power detector

The ADL5920 is an ultra-wide band bi-directional bridge detector that can simultaneously measure forward and reverse RMS power levels in a signal path along with return loss.

Maximum input signal on each of the RF ports (RFIP and RFOP) is +30dBm with handling capability for open and shorted loads.

Supplied in a 32 lead, 5  x 5mm LFCSP, power is 5V at 150mA (powered down via PWDN pin), and operation is over -40 to +85°C.

The part is sampling now, with production planned in December, and there is an evaluation board.

Spplications are expected in: broadband in-line power and return loss measurement in wireless transmitters, signal generators, network analysers and wireless communication testers.

At a glance

• Frequency Range: 9KHz to 7GHz
  Insertion Loss:  0.9dB@1GHz   1.9dB@6GHz
• Input and Output Return Loss/VSWR: <1 GHz   >15dB (<1:1.4), 1 to 3GHz    15dB (1:1.4), 3 to 6GHz: 13dB (1:1.6)
• OIP3: +70.5 dBm
• Directivity:  23dB@1GHz    14dB@3GHz    6dB@6GHz
• Max Input Power: +30 dBm
• Forward power measurement range: 50dB at 1GHz
• Linear-in-dB outputs for RMS and return loss