Phase Shifter Variable Isolation Port Impedance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Phase shifters used in radio communication systems experience power loss when controlling phase in steps of 90 degrees due to the connection of 90-degree dividers to resistors, leading to unnecessary power consumption.
Innovation Solution
A phase shifter design where the impedance of the 90-degree divider's isolation port is variable, allowing for minimal loss during phase control in steps of 90 degrees by appropriately setting the impedance between the source and drain of the transistor, and using gain-variable amplifiers to adjust signal amplitudes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the 90-degree divider is connected to resistors for phase control, then the phase shifting function is achieved, but power loss increases due to unnecessary power consumption
Solution Approach 1:
The patent applies the dynamics principle by making the impedance of the isolation port variable rather than fixed. The impedance is dynamically adjusted based on the phase control amount: when the phase control amount is 0° or 90°, the impedance is set to a first value (e.g., low impedance to ground) to prevent power loss; when the phase control amount is other values, the impedance is set to a second value (e.g., high impedance or open) to maintain proper signal isolation. This dynamic adaptation resolves the contradiction by optimizing power efficiency only when needed while maintaining phase control accuracy otherwise.
Solution Approach 2:
The patent applies the parameter changes principle by changing the impedance parameter of the isolation port based on the phase control amount. Specifically, the impedance is switched between a first value (such as 0Ω or low impedance) when phase control is at 0° or 90°, and a second value (such as open circuit or high impedance) for other phase angles. This parameter transformation allows the system to minimize power loss at specific phase points while maintaining functional integrity across all phase control ranges.
2Loss of energy
If fixed impedance is used in the isolation port, then circuit simplicity is maintained, but transmission loss increases during phase control operations
Solution Approach 1:
The patent transforms the static impedance configuration into a dynamic one by introducing control logic that adjusts the isolation port impedance based on the phase control amount. This dynamic configuration reduces transmission loss by adapting the impedance state to the operational requirements, accepting the trade-off of increased circuit complexity as necessary for achieving lower energy loss in the phase shifter system.
Solution Approach 2:
The patent changes the impedance parameter of the isolation port from a fixed value to a variable value that depends on the phase control amount. By switching between a first impedance value (e.g., low impedance to ground) and a second impedance value (e.g., high impedance or open circuit), the system optimizes transmission efficiency while managing the added complexity through controlled parameter transformation.
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 solution reduces transmission loss and maintains high electric power levels during phase control in steps of 90 degrees, improving the efficiency of phase shifting operations.
Implementation Method 1
an impedance between a source and a drain of the transistor is set to a maximum value when the phase control amount is 0 degrees, and set to a minimum value when the phase control amount is 90 degrees
Implementation Method 2
gain-variable amplifiers to adjust signal amplitudes
Data Source
AI summary
A 0-to-90-degree phase shifter (13) includes a voltage-variable power supply (16), a transistor (17), a 90-degree divider (18), gain-variable amplifiers (19) (19-1 and 19-2), and a combiner (20). The 90-degree divider (18) divides an input signal into a signal to which a 90-degree phase is given and a signal to which no phase is given, and outputs the divided signals to the gain-variable amplifiers (19). The gain-variable amplifiers (19) (19-1 and 19-2) output signals whose amplitudes are changed according to a phase control amount to the combiner (20). The combiner (20) combines the signals input from the two gain-variable amplifiers (19) and outputs the combined signal. The impedance between the source and the drain of the transistor connected to the isolation port of the 90-degree divider (18) can be changed as appropriate.