A packaged broadband monolithic variable gain amplifier implemented in AlGaAs/GaAs HBT technology

Broadband monolithic variable gain amplifiers (VGAs) were designed and fabricated using an AlGaAs/GaAs HBT technology. The VGAs were housed in high-speed packages. The packaged VGAs provided 10-16 dB adjustable gain with approximately /spl plusmn/1 dB gain variations and constant group delay in the DC-26 GHz band, and showed better than 10 dB input/output return losses in the amplifier passband. These VGAs can be used in fiber optic transmission systems with data rates up to 30 GBit/s.