Cascaded Distributed Amplifier Blocks for Gain-Bandwidth Balance
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Solution Overview
Problem
Conventional distributed amplifiers face a challenge in improving gain without degrading bandwidth as the number of stages increases, leading to significant signal attenuation in the input and output transmission lines.
Innovation Solution
A distributed amplifier design with N amplifier blocks connected in cascade, where each block includes specific impedance settings and biasing configurations, such as 50Ω characteristic impedances and tailored power supply voltages, to enhance gain without affecting bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the number of stages is increased to improve gain, then the gain is improved, but the bandwidth deteriorates significantly
Solution Approach 1:
The distributed amplifier is divided into multiple independent amplifier blocks, each with its own transmission lines and unit cells. By segmenting the amplifier into blocks with optimal stage counts, the patent avoids the bandwidth deterioration that occurs when a single amplifier has too many stages, while still achieving high overall gain through cascaded connection of multiple blocks.
Solution Approach 2:
The patent transitions from a single-dimensional approach (one long transmission line with many stages) to a multi-dimensional approach (multiple parallel transmission lines in each block, cascaded in series). This dimensional change allows the amplifier to achieve both high gain and wide bandwidth by distributing the amplification function across multiple parallel paths within each block.
2Power
If the number of stages is increased, then the DC gain is improved, but the bandwidth deteriorates due to signal attenuation in transmission lines
Solution Approach 1:
By segmenting the amplifier into multiple blocks, each with a limited number of stages, the patent reduces the signal attenuation that occurs in the transmission lines of any single block. Each block can be optimized to have the optimal number of stages that minimizes attenuation while providing sufficient gain, and the cascaded structure accumulates the overall gain without compounding the attenuation problem.
Data Source
AI summary
An embodiment is a distributed amplifier including amplifier blocks, each of the amplifier blocks including a first transmission line to receive input of a signal to an input end, a second transmission line to output a signal from an output end, a first termination resistor having a first end connected to a terminal end of the first transmission line, a second termination resistor having a first end connected to an input end of the second transmission line, and unit cells arranged along the first and second transmission lines, each of the unit cells having an input terminal connected to the first transmission line and an output terminal connected to the second transmission line, the amplifier blocks are connected in cascade such that a terminal end of the second transmission line of one of the amplifier blocks is connected to the first transmission line of a subsequent amplifier block.