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In this paper, an aging small-signal model for degradation prediction of microwave heterojunction bipolar transistor (HBT) S-parameters based on prior knowledge neural networks (PKNNs) is explored. A dual-extreme learning machine (D-ELM) structure with an adaptive genetic algorithm (AGA) optimization process is used to simulate the fresh S-parameters of InP HBT devices and the degradation of S-parameters after accelerated aging, respectively. In addition to the reliability parametric inputs of the original aging problem, the S-parameter degradation trend obtained from the aging small-signal equivalent circuit is used as additional information to inject into the D-ELM structure. Good agreement was achieved between measured and predicted results of the degradation of S-parameters within a frequency range of 0.1 to 40 GHz. [ABSTRACT FROM AUTHOR]

• All the extrinsic parameters are determined by employing S-parameter measured only under cut-off and normal bias conditions. • The scaling rule for the intrinsic base-emitter capacitance and the parameter scanning method for the base–collector extrinsic capacitance are used to obtain all capacitance parameters. The extrinsic inductances and resistances are obtained by the direct extraction method. Finally, these more accurate parasitic values are used as the initial values for parameter optimization , and the optimal parasitic parameter values are obtained by fine-tuning. • The proposed method not only eliminates the critical measurement of the open-collector condition, but also greatly improves the efficiency and accuracy of parameter optimization. An improved parasitic parameters extraction method for InP heterojunction bipolar transistor (HBT) is developed. The difference between this method and previous methods is that all parasitic parameters can be extracted by relying only on the S-parameters measured under the cut-off and normal bias conditions. All the capacitance parameters in the equivalent circuit at the low-frequency cut-off can be extracted by combining the analytical closed formulas and the parameter scanning method. The intrinsic resistance R bi is obtained indirectly by extracting the extrinsic resistance R e based on the Z-parameter method in the normal bias conditions. By de-embedding the parasitic capacitances, all the values of parasitic inductances and extrinsic resistances are obtained by the direct extraction method under the cut-off condition. The proposed method not only eliminates the critical measurement of the open-collector condition, but also greatly improves the efficiency and accuracy of parameter optimization. For different sizes and bias conditions of InP HBT devices, the excellent agreement between simulated and measured results is verified all over the frequency range of 0.4–50 GHz. [ABSTRACT FROM AUTHOR]

In this paper, a fully integrated Ku-band voltage controlled oscillator (VCO) with low phase noise is presented in a GaAs heterojunction bipolar transistor (HBT) technology. A cross-coupled configuration is employed to achieve low phase noise, and to achieve high output power, the largest HBT and higher bias current are adopted. The implemented VCO demonstrates that the oscillation frequency is from 13.77GHz to 14.8GHz, with a maximum 4.83dBm output power at 13.77GHz. The phase noise of the VCO is 100.2dBc/Hz at 1MHz offset from 14.36GHz oscillation frequency. The VCO consumes 61.2mW from 6V supply and occupies an area of 0.51mmmm. Finally, the figure-of-merits (FOMs) for VCOs are discussed. [ABSTRACT FROM AUTHOR]

A rigorous and systematic analytical-based parameter extraction technique for the augmented small-signal equivalent-circuit model dedicated to III-V-based heterojunction bipolar transistors (HBTs) is presented. The proposed extraction method relies exclusively on S -parameters measured at low and high frequencies. The extraction algorithm is derived by peeling peripheral elements from the small-signal equivalent circuit with very few simplified approximations throughout the whole extraction process. All of the elements' parameters of the small-signal equivalent-circuit model considering the base-collector and base-emitter capacitances distributed effect are determined accurately through the developed extraction technique. Excellent agreement is obtained demonstrating the comparisons between the small-signal S -parameters measured and modeled results for 0.7 μm InGaAs/InP HBTs over a wide range of bias points within the frequency range of 0.1–40 GHz, which verifies the validity and the accuracy of this model and extraction technique. [ABSTRACT FROM AUTHOR]

For predicting the effects of gamma radiation on gallium–arsenide (GaAs) heterojunction bipolar transistors (HBTs), a novel model is presented in this paper, considering the radiation effects. Based on the analysis of radiation-induced degradation in forward base current and cutoff frequency, three semiempirical models to describe the variation of three sensitive model parameters are used for simulating the radiation effects within the framework of a simplified vertical bipolar inter-company model. Its validity was demonstrated by analysis of the experimental results of GaAs HBTs before and after gamma radiation. [ABSTRACT FROM AUTHOR]

In this article, 3 MeV proton irradiation-induced degradation in InP/InGaAs double heterojunction bipolar transistors (DHBTs) is studied, the fluence up to 5 × 10 12 protons/cm 2 , meanwhile 10 MeV proton irradiation is investigated in order to compare the differences induced by different proton energy irradiation. The devices exhibit good tolerance up to 5 × 10 11 protons/cm 2 . The concentration of vacancies at different proton fluences can be calculated from SRIM. Being donor-like defects, the In and Ga vacancies act as compensation center while As vacancy acts as an acceptor-like defect. Adding the vacancies model into Sentaurus device simulator, simulation results match well with the trends of measured data. [ABSTRACT FROM AUTHOR]

Highlights: [•] The irradiation effects on InGaP/GaAs SHBTs are focused on low-energy proton. [•] To analyze the irradiation-induced damage, the ideality factor of I BE is extracted. [•] The degradation of f T after irradiation at a fixed bias is presented theoretically. [•] The open-collector technique is used to extract the access resistances. [•] The lower the proton energy, the greater the influence on the devices. [ABSTRACT FROM AUTHOR]

Abstract: In this article, we report the effect of gamma irradiation on the DC characteristics of InGaP/GaAs single heterojunction bipolar transistors (SHBTs) based on the simulation with the extracted model parameters from experiment data before irradiation, after irradiation and after annealing. A simplified Vertical Bipolar Inter-Company (VBIC) static model is proposed to study the operational mechanism and the DC characteristics of SHBTs. The results show that the defects induced by irradiation are responsible for the changes on the DC characteristics of the devices. [Copyright &y& Elsevier]