Analysis and design of matched-impedance wide-band amplifiers with multiple feedback loops using 0.35µm TSMC complimentary metal oxide semiconductor technology: article / Subhi Radzuan

The realization of matched impedance wide band amplifiers simulated using 0.35µm CMOS technology is reported. The technique of multiple feedback loops was used to archive terminal impedance matching and wide bandwidth. The experimental results showed that a small signal gain of 12.7dB a 3-dB bandwidth of 1.7GHz with in band input or output return loss less than 10dB were obtained. These values agreed well with those predicted from the analytic expressions that have derived for voltage gain, transimpedance gain. bandwidth, and input and output impedances. A general method for the determination of frequency responses of input/output return losses (or S₁₁. S₂₂) from the poles of voltage gain was proposed. The intrinsic overdamped characteristic of this amplifier was proved and emitter capacitive peaking was used to overcome this problem. The tradeoff between the input impedance matching and bandwidth was also found.