A novel design technique for bandwidth enhancement in InGaP HBT broadband amplifier

A design technique, the cascode amplifier with series RLC peaking, for broadband amplifiers to achieve high gain-bandwidth product is proposed and demonstrated in this paper. Implemented with 27 /spl mu/m InGaP HBTs, the cascode amplifier with series RLC peaking enhances approximately 200% of the amplifier bandwidth compared with a normal cascode amplifier. The measurement results show that the cascode broadband amplifier with this technique has 7.5 dB small-signal gain over the operating frequency range from 30 kHz to 23 GHz. S/sub 11/ and S/sub 22/ ore lower than -10 dB, and S/sub 12/ is lower than -40 dB.