The maximum operating region in SiGe HBTs for RF power amplifiers

Abstract

Absfrocl -Microwave waveforms of SiGe HBTs have been directly measured. The maximum operating region has been experimentally investigated by sweeping the load lines and power of the input signal. The device is found to operate beyond the conventional BVceo, while GaAs HBTs cannot survive at that voltage. The conventional BVceo is found lo limit the average Vc of the maximum load lines, but has no influence on the peak voltsge. Another BVcw measured with a voltage generator is proposed to represent the avalanche breakdown instead of the conventional one. IEEE M T -S Digest0-7803-7239~5/02/$10.00 D 2002 IEEE

Low-power 20-Gb/s SiGe BiCMOS driver with 2.5 V output swing

“…In high-speed applications, there are fast transitions and a transistor might momentarily experience a large V CE . For example, [7] provides experimental data on the breakdown in a power amplifier and concludes that BV CEO is the limit for "average" C-E voltage. However, the case of a narrowband circuit, such as power amplifier, is different from broadband amplifiers where depending on the sequence of input data, a transistor can remain in a certain operating condition for a long time (i.e.…”

“…In (7), f T1 is the transit frequency at collector current of I M /2, which is smaller than f T,max by 10% to 30%, if the transistors of the output stage are designed to provide the maximum f T at I M . Using a technology with higher transit frequency can reduce the power dissipation in the EF stage whereas the power dissipated in the output stage may not be affected.…”

“…Also (7) gives I EF of 5 mA for I M = 100 mA, assuming a transit frequency of 110 GHz. This results in a supply current of 30 mA for the buffer, assuming equal bias current in all six EFs, for simplicity.…”

A 21-26-GHz SiGe bipolar power amplifier MMIC

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A New Circuit Model for Designing Fully Integrated Class-A Power Amplifier

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