Cascaded single-stage amplifier with improved gain-frequency performance using frequency-dependent lossy artificial lines

A broadband GaAs high power millimeter wave amplifier with high gain and flatness

“…In our work, smaller resistors (R1, R4 and R5 in the gate bias circuits and R2 and R3 in the drain bias circuits, as shown in Fig. 2) are used to improve the gain flatness instead of the loss artificial TLs [9]. As a result, the measured S21 is improved to 21.8±0.6 dB in the 38-67 GHz band.…”

“…The second improvement worth noting is that to improve the gain flatness by introducing small resistors-capacitors in the bias circuits. It has been proven that the gain can be tempered to have a flat response by introducing transistor loss and using series RC networks that form the artificial transmission lines [9]. In our work, smaller resistors (R1, R4 and R5 in the gate bias circuits and R2 and R3 in the drain bias circuits, as shown in Fig.…”

“…*,*-* 4 that a method to improve the gain flatness is to increase transistor loss. We adopted small resistors-capacitors in the bias circuits, instead of Frequency-Dependent Lossy artificial lines [9]. The measured gain flatness is improved to 21.8±0.6 dB in the 38-67 GHz band.…”

“…The CDA was used to extend the frequency band followed by CSSDA for the gain stages. In 2007, Virdee et al [9] further revealed that the gain flatness could be improved by tuning the loss of the transistor in the CSSDA. This modified topology was called lossy CSSDA.…”

“…[10]. The brief history of the distributed amplifier and the detailed improvements are summarized in Fig.1. 1.Conventional Distributed Amplifier [2,3] 3.CSSDA [5][6][7] 4.CDA-CSSDA [8] 5.Lossy CSSDA [9] 8.CDA-Cascaded single-ended stages [10] This work 2.SSDA [4] Power Improvement Gain Flatness Improvement …”