Common-Emitter Amplifier With Pre-Embedding Inductors for Wider THz Bandwidth
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Solution Overview
Problem
Terahertz wireless communication systems face challenges in power amplification due to the rapid decrease in active device gain as the operating frequency approaches the maximum oscillation frequency of transistors, leading to poor performance of silicon-based amplifiers without gain enhancement technologies.
Innovation Solution
A common-emitter amplifier with unilateral pre-embedding inductors is introduced, which reduces the required value of parallel embedding inductors and enhances gain, while staggered tuning between stages expands the bandwidth of the amplifier.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If parallel embedding networks and series embedding networks (Y/Z-embedding networks) are adopted to increase the maximum available gain of an active double port network, then the gain is improved, but the required inductance values become too large, making implementation difficult
Solution Approach 1:
The patent divides the embedding network into two separate parts: a pre-embedding network connected to the base and a post-embedding network connected to the collector. This segmentation allows each network to use smaller, more manageable inductance values while achieving the same gain enhancement effect as a single large inductance value would provide.
Solution Approach 2:
The pre-embedding network is applied before the transistor stage to pre-condition the input signal and impedance. By performing the embedding action in advance at both the input and output sides, the patent reduces the burden on the transistor itself and enables the use of smaller inductors that are easier to implement at terahertz frequencies.
2Ease of manufacture
If inductance values required for realizing the Y/Z-embedding network are reduced, then the implementation difficulty is reduced, but the gain enhancement capability is compromised
Solution Approach 1:
The patent combines the effects of pre-embedding and post-embedding networks to achieve cumulative gain enhancement. By merging the impedance transformation effects of both networks, the system achieves the same gain enhancement as a single large inductance while using multiple smaller, more manageable inductors throughout the signal path.
3Power
If a common-emitter amplifier structure with Y/Z-embedding network is used to achieve gain enhancement, then the gain is improved, but the bandwidth is reduced due to resonance process limitations
Solution Approach 1:
The patent applies staggered tuning to make the amplifier stages operate at different optimized frequencies rather than a single fixed frequency. This dynamic approach allows the amplifier to maintain high gain across a broader frequency range by having each stage contribute to different portions of the bandwidth, effectively expanding the overall operating bandwidth while preserving gain enhancement benefits.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The proposed amplifier achieves improved gain performance by reducing the difficulty of implementing parallel embedding inductors at high frequencies and expands the bandwidth, effectively addressing the limitations of existing terahertz amplifiers.
Implementation Method 1
By introducing a unilateral pre-embedding inductor into a collector, the required value of a parallel embedding inductor is reduced
Implementation Method 2
the common-emitter amplifier structure with the Y/Z-embedding network relies on a resonance process of inductors and capacitors
Implementation Method 3
by performing staggered tuning between stages to expand bandwidth
Data Source
AI summary
A common-emitter amplifier with unilateral pre-embedding inductors includes: an input matching circuit, a first-stage amplification circuit, a first-stage interstage matching circuit, a second-stage amplification circuit, a second-stage interstage matching circuit, a third-stage amplification circuit, and an output matching circuit. The common-emitter amplifier is configured to: make an input signal sequentially enter bases of common-emitter transistors of the first-stage, second-stage, and third-stage amplification circuits, make the input signal be amplified stage by stage by the common-emitter transistors, and finally make an amplified input signal obtained by amplifying of each common-emitter transistor output through a collector of each common-emitter transistor. The common-emitter amplifier is configured to introduce interstage staggered tuning to expand bandwidth to address a narrowband problem. The unilateral pre-embedding inductors are configured to reduce a required value of the parallel embedding inductor to reduce difficulty of implementing the parallel embedding inductor, conducive to the realization of transmission lines.