This paper describes new variolosser circuits which are suitable for use in high quality broadband IF amplifiers operating at several hundred MHz, and offering substantial improvements in power consumption, temperature stability, bandshape stability, minimum attenuation and attenuation range. Three variolossers of this type are used in the automatic gain control for the IF amplifier used in the short hop radio system experiment.
We present an analysis, a design procedure, and extensive measurements. As an example of the performance to be expected, one experimental varioloser has a minimum attenuation of 1.35 dB, a maximum attenuation of 19.5 dB, and is flat to ±0.15 dB over a 40 percent band centered at 300 MHz.