I am working on a design where I need to output a 3GHz sine wave with a constant amplitude (Automatic Gain control / AGC). The HMC993 would have been perfect (VGA with integrated log power detector), but is now obsolete and has no replacement part.
It seems now that there are less analog AGC circuits and more of the Variables Gain Amplifier (VGA) are turning to Digital Variable Gain Amplifier (DVGA). Am-I right, and isn't it a little bit more cumbersome to use multiples parts instead of, for exemple, the HMC993? Maybe there is a simple circuit that I haven't understood, any help would be appreciated.
Thanks for your inquiry. We have other VGA and Detector products that may work for your application. A couple of analog devices that may apply are: ADL5330 analog VGA and a log detector, AD8318 . Details are available on Analog.com. See also app note AN-1507: Stable, Closed-Loop, Automatic Power Control for RF Applications; available on the ADL5330 product page.