Advanced tunneling diodes for high-frequency applications and wireless communication systems
University of Manchester, 2023
Online
Hochschulschrift
Zugriff:
The research was focused on developing and enhancing a critical InP-based technology, namely the Resonant Tunnelling Diode (RTD). This development was initially established through a detailed modelling investigation of Double Barrier Quantum Well (DBQW) InGaAs/AlAs RTDs to optimise the diode's DC and RF characteristics by utilising asymmetrical spacer structures that target low peak voltages and short transit times for use in high frequency and low dc power consumption applications. The results of the asymmetrical spacer RTDs indicated that thickening the emitter spacer significantly decreased the peak voltage and current, while thickening the collector spacer increased the peak voltage and current. A few modifications were made to the asymmetrical spacers RTDs to increase their negative differential conductance (NDC) and output power while maintaining low peak voltages. Reduced quantum well thickness aided in increasing the NDC, output power, and operating frequency, but at the expense of significantly increased peak voltage. The structure was then further modified by increasing the Indium content of the quantum well. This step enabled the achievement of NDC values in the range of 20 mS and 50 mS and output power in the range of 200 μW and 450 μW while maintaining a low peak voltage (i.e. 0.14 V to 0.35 V) and a high operating frequency (i.e. 575 GHz to 700 GHz). This work demonstrated that RTDs are suitable for high output power radio frequency (RF) applications and low power or ultra-low power radio frequency (RF) applications. This project also involved the modelling and theoretical analysis of an X-band reflection-based amplifier using InGaAs/AlAs RTD sample #300 with a 16 μm² mesa size. The model was constructed using a lumped element branch-line coupler with two active RTD loads. The analysis included component extraction from the RTD equivalent circuit and passive component modelling. By constructively combining the amplified in-phase electromagnetic waves at the output port, it was possible to predict a simulated gain of 13.5 dB at 10 GHz while consuming only 3.2 mW of DC power. This gain results in a figure of merit of 4.22 dB/mW, confirming the amplifier's superior performance compared to other X-band amplifiers using other technologies (e.g. 65nm CMOS, GaN transistors). Due to the high gain and low dc power consumption of the RTD amplifiers compared to other semiconductor technologies such as CMOS and GaN transistors, they could be an excellent candidate for 5G/6G wireless communication systems. A 2D electromagnetic model of an RTD oscillator based on a 4 μm² InGaAs/AlAs RTD (sample #300) coupled to a CPW resonator predicts an output power of 83 μW at 100 GHz fundamental frequency. The spectrum also shows that the first harmonic occurs at 200.4 GHz with extremely low power of 0.09 μW. The RTD oscillator's passive components, such as NiCr resistors, parallel plate capacitors, and CPW transmission lines, were all modelled. Due to the rapidly increasing data rates for 5G/6G wireless communication systems, implementing an ultra-high-speed RTD transmitter capable of operating at speeds exceeding 20 Gb/s becomes critical. Thus, the RTD oscillators developed in this thesis may aid 5G/6G technologies in overcoming the speed limitations of CMOS and GaN technologies.
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Advanced tunneling diodes for high-frequency applications and wireless communication systems
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Autor/in / Beteiligte Person: | Alqurashi, Ahmed ; Missous, Mohamed ; Majewski, Leszek |
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Veröffentlichung: | University of Manchester, 2023 |
Medientyp: | Hochschulschrift |
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