Microwave noise parameter modeling of a GaAs HEMT under optical illumination

Abstract

This article presents the experimental results of the modeling of noise parameters for a GaAs HEMT under light exposure. The noise model is based on the equivalent-circuit representation expanded by assigning an equivalent noise temperature to each resistor. To take into account for the significant increase of the gate current under light exposure, two resistances with the associated noise temperatures have been added at the input and feedback of the intrinsic section of the circuit. The validity of the developed technique has been confirmed by the achieved good agreement between measured and simulated microwave noise parameters with and without optical illumination. V C 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:151-154, 2016; View this article online at wileyonlinelibrary.com.

Comparative analysis of microwave low‐noise amplifiers under laser illumination

“…The DC characterization showed that, under light exposure, a current increase occurred for all devices due to the threshold voltage shift related with the photovoltaic effect (illuminated current I DS = 15, 27, and 40 mA, respectively) . Furthermore, both DC and RF transconductance g m increased with illumination as well .…”

Black‐box noise modeling of GaAs HEMTs under illumination

“…The resulting models are shown in Figure 3 As already pointed out, one of the purposes of the present work was to verify the applicability of the proposed methodology to properly represent the noisy behavior of a HEMT device under laser excitation. To this respect, few references can be found in the literature [23][24][25][26]: Reasonably, under laser illumination, generation and recombination phenomena might arise in the gate-source and gate-drain regions, thus originating two additional noise sources located in parallel to the relevant junctions. Those noise sources affect the noise parameters in a way that they do not satisfy the DC physical constraints as is usual for a well-behaving high-frequency HEMT or MESFET device (in the frequency and temperature ranges in which 1/f noise and quantum effects can be neglected).…”

“…Noise behavior of devices subjected to illumination is a topic that has not yet been investigated extensively [23][24][25][26]. As a consequence, applying conventional noise modeling techniques, that is, based on the concept of equivalent temperatures [33][34][35], has been postponed to a future work, whereas a general, black-box model was adopted to extract and represent device noise parameters.…”

“…gain control of amplifiers, frequency tuning or locking in oscillators, and phase shifting in phase shifters) [1][2][3][4][5][6]. Despite that several studies have been devoted to the investigation of the behavior of the GaAs HEMT under optical illumination , the noise performance has been barely analyzed with light [23][24][25][26], while the attention has been mainly focused on the DC, small signal, and large signal characteristics [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. In this context, the present paper is aimed at modeling the noise behavior of a GaAs pseudomorphic HEMT (pHEMT) with and without laser illumination.…”

Equivalent‐circuit–based modeling of the scattering and noise parameters for multi‐finger GaAs pHEMTs

“…To contribute to the advancement of this semiconductor technology, many studies have been developed over the years to experimentally characterize the microwave linear performance of GaAs HEMTs and pHEMTs in terms of scattering (S-) and noise (N-) parameter measurements and to reproduce the measured behavior with equivalent-circuit based models. [8][9][10][11][12][13][14][15][16][17][18] This study is focused on the characterization and modeling of advanced on-wafer GaAs pHEMTs at microwave frequencies. To investigate the scaling of the performance of the studied transistor technology, four interdigitated devices with different number of gate fingers are analyzed.…”