Found in Motorola documentation from the 90's, this circuit has a high input impedance. The power supply must be symmetrical. The circuit can be implemented with modern operational amplifiers.
This converter for the 150 MHz band was found in an American documentation. Transistors are...
The configuration shown is from the National Semiconductor Linear Applications Handbook. The...
We found this circuit in a 2003 publication. The indicated coil is for capturing the signals in an...