Ultra-Wideband Two-Bit Phase Shifter With RC Orthogonal Network
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Solution Overview
Problem
Existing phase shifters face challenges in achieving wide bandwidth, high phase shifting accuracy, and compact size while maintaining low insertion loss and ease of control, particularly in microwave communication systems.
Innovation Solution
An ultra-wideband two-bit phase shifter design utilizing an active balun, differential amplifiers, a switch matrix, and an RC orthogonal network to convert single-ended signals into differential signals, achieving 90-degree, 180-degree, and 270-degree phase shifts with high precision and balanced amplitude through a simple control method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If transmission-line-type phase shifters are used, then the circuit structure is simple, but the operating bandwidth is narrow
Solution Approach 1:
The phase shifter is divided into multiple stages, each contributing a portion of the total phase shift. This segmentation allows the overall bandwidth to be expanded while maintaining manageable complexity in each individual stage.
Solution Approach 2:
Multiple phase shifting mechanisms are combined in a single integrated circuit, merging transmission line sections with switching networks to achieve both wide bandwidth and controlled phase shifting in one unified structure.
2Adaptability or versatility
If multi-stage series connection is used to expand bandwidth, then the operating bandwidth increases, but the circuit area and insertion loss increase
Solution Approach 1:
Phase shifting functions are nested within a compact switched capacitor network structure, where multiple phase shift stages are integrated in a nested arrangement that minimizes the overall circuit footprint while maintaining the required bandwidth.
Solution Approach 2:
The circuit transitions from planar transmission line layouts to a three-dimensional integrated structure using vertical stacking and layered capacitor arrangements, effectively reducing the circuit area while preserving bandwidth performance.
3Adaptability or versatility
If reflection-type phase shifters are used, then the bandwidth is expanded, but the circuit area becomes large
Solution Approach 1:
The quarter-wavelength transmission line sections inherent in reflection-type phase shifters are extracted and replaced with equivalent lumped element circuits, removing the space-consuming distributed structures while retaining the bandwidth expansion capability.
4Adaptability or versatility
If all-pass network phase shifters based on magnetic coupling are used, then the bandwidth reaches multiple octaves, but the phase shifting degree is limited
Solution Approach 1:
The phase shifter employs dynamically controllable switching elements that can rapidly reconfigure the signal path, enabling precise phase shifting control across the entire bandwidth range. This dynamic control mechanism overcomes the static limitations of magnetic coupling-based approaches.
Solution Approach 2:
The circuit utilizes switching capacitors that change their effective capacitance values based on control signals, thereby dynamically adjusting the phase shift amount. This parameter change mechanism enables precise control of phase shifting degree while maintaining wide bandwidth operation.
Data Source
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AI summary
An ultra-wideband two-bit phase shifter, comprising an active balun, a first differential amplifier, a second differential amplifier, a third differential amplifier, a switch matrix, an RC orthogonal network and a single-pole double-throw switch. The active balun receives a single-ended signal and converts the single-ended signal into a pair of differential signals, and two output signals are respectively connected to two input ports of the first differential amplifier; the first differential amplifier conducts wave shaping and gain compensation on the two received signals, and selects different branches by means of the switch matrix to realize a 180-degree phase shift; the differential signals generates two pairs of orthogonal signals by means of the cascaded RC orthogonal network through the switch matrix, and the two pairs of orthogonal signals are respectively cascaded to the second and third differential amplifiers; the single-pole double-throw switch selects different branches of the second and third differential amplifiers to generate a 90-degree phase shift, thereby realizing a 90-degree phase shift, a 180-degree phase shift and a 270-degree phase shift. The ultra-wideband two-bit phase shifter has the advantages of ultra-wideband, high phase-shifting accuracy, good amplitude balance, simple control method and high integration.